diff --git a/CMakeLists.txt b/CMakeLists.txt
index 43508ae83f..7c8144d78a 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -138,13 +138,13 @@ OPTION(FSO_BUILD_WITH_DISCORD "Build with Discord support" ON)
 
 OPTION(FSO_BUILD_WITH_OPENGL "Enable compilation of the OpenGL renderer" ON)
 OPTION(FSO_BUILD_WITH_OPENGL_DEBUG "Enables debug option for OpenGL" OFF)
-OPTION(FSO_BUILD_WITH_OPENGL_ES "When building OpenGL, use OpenGL ES compatibility layer (External shaders only!)" OFF)
+OPTION(FSO_BUILD_WITH_OPENGL_ES "When building OpenGL, use OpenGL ES compatibility layer" OFF)
 
 OPTION(FSO_BUILD_WITH_VULKAN "Enable compilation of the Vulkan renderer" ON)
 
 if(NOT FSO_BUILD_WITH_OPENGL AND FSO_BUILD_WITH_OPENGL_ES)
 	# Disable GLES if not building with OpenGL
-	set(FSO_BUILD_WITH_OPENGL_ES OFF FORCE)
+	set(FSO_BUILD_WITH_OPENGL_ES OFF CACHE BOOL "" FORCE)
 endif()
 
 
diff --git a/code/def_files/data/effects/batched-f.sdr b/code/def_files/data/effects/batched-f.sdr
index 660787fe4e..e46e5208af 100644
--- a/code/def_files/data/effects/batched-f.sdr
+++ b/code/def_files/data/effects/batched-f.sdr
@@ -1,12 +1,16 @@
+#ifdef GL_ES
+precision highp float;
+precision highp sampler2DArray;
+#endif
 
 #include "gamma.sdr"
 
+layout(location=0) out vec4 fragOut0;
+
 #ifdef VULKAN
 layout (location = 0) in vec4 fragTexCoord;
 layout (location = 1) in vec4 fragColor;
 
-layout (location = 0) out vec4 fragOut0;
-
 layout (set = 1, binding = 1) uniform sampler2DArray baseMap;
 
 layout (set = 2, binding = 0, std140) uniform genericData {
@@ -17,8 +21,6 @@ layout (set = 2, binding = 0, std140) uniform genericData {
 in vec4 fragTexCoord;
 in vec4 fragColor;
 
-out vec4 fragOut0;
-
 uniform sampler2DArray baseMap;
 
 layout (std140) uniform genericData {
diff --git a/code/def_files/data/effects/batched-v.sdr b/code/def_files/data/effects/batched-v.sdr
index 9f1efb6f21..87bb3983ac 100644
--- a/code/def_files/data/effects/batched-v.sdr
+++ b/code/def_files/data/effects/batched-v.sdr
@@ -1,3 +1,7 @@
+#ifdef GL_ES
+precision highp float;
+#endif
+
 #ifdef VULKAN
 layout (location = 0) in vec4 vertPosition;
 layout (location = 1) in vec4 vertColor;
diff --git a/code/def_files/data/effects/bloom-comp-f.sdr b/code/def_files/data/effects/bloom-comp-f.sdr
index 20d8859a64..74fee1c1c1 100644
--- a/code/def_files/data/effects/bloom-comp-f.sdr
+++ b/code/def_files/data/effects/bloom-comp-f.sdr
@@ -1,11 +1,16 @@
+#ifdef GL_ES
+precision highp float;
+precision highp sampler2D;
+#endif
+
+layout(location=0) out vec4 fragOut0;
 
 #ifdef VULKAN
 layout(location = 0) in vec2 fragTexCoord;
-layout(location = 0) out vec4 fragOut0;
 layout(set = 1, binding = 1) uniform sampler2D bloomed;
 #else
 in vec4 fragTexCoord;
-out vec4 fragOut0;
+
 uniform sampler2D bloomed;
 #endif
 
diff --git a/code/def_files/data/effects/blur-f.sdr b/code/def_files/data/effects/blur-f.sdr
index 8063b8e4e0..47bcf42da0 100644
--- a/code/def_files/data/effects/blur-f.sdr
+++ b/code/def_files/data/effects/blur-f.sdr
@@ -1,9 +1,15 @@
+#ifdef GL_ES
+precision highp float;
+precision highp int;
+precision highp sampler2D;
+#endif
+
+layout(location = 0) out vec4 fragOut0;
+
 #ifdef VULKAN
 layout(location = 0) in vec2 fragTexCoord;
-layout(location = 0) out vec4 fragOut0;
 layout(set = 1, binding = 1) uniform sampler2D tex;
 #else
-out vec4 fragOut0;
 in vec4 fragTexCoord;
 uniform sampler2D tex;
 #endif
diff --git a/code/def_files/data/effects/brightpass-f.sdr b/code/def_files/data/effects/brightpass-f.sdr
index e1632a23d1..219f65bd06 100644
--- a/code/def_files/data/effects/brightpass-f.sdr
+++ b/code/def_files/data/effects/brightpass-f.sdr
@@ -1,12 +1,18 @@
+#ifdef GL_ES
+precision highp float;
+precision highp sampler2D;
+#endif
+
+layout(location = 0) out vec4 fragOut0;
+
 #ifdef VULKAN
 layout(location = 0) in vec2 fragTexCoord;
-layout(location = 0) out vec4 fragOut0;
 layout(set = 1, binding = 1) uniform sampler2D tex;
 #else
 in vec4 fragTexCoord;
-out vec4 fragOut0;
 uniform sampler2D tex;
 #endif
+
 const float Luminance = 0.08;
 const float fMiddleGray = 0.2;
 const float fWhiteCutoff = 0.4;
diff --git a/code/def_files/data/effects/copy-f.sdr b/code/def_files/data/effects/copy-f.sdr
index 28c29bdfac..52510a75a7 100644
--- a/code/def_files/data/effects/copy-f.sdr
+++ b/code/def_files/data/effects/copy-f.sdr
@@ -1,10 +1,16 @@
+#ifdef GL_ES
+precision highp float;
+precision highp sampler2D;
+precision highp sampler2DArray;
+#endif
+
+layout(location = 0) out vec4 fragOut0;
+
 #ifdef VULKAN
 layout(location = 0) in vec2 fragTexCoord;
-layout(location = 0) out vec4 fragOut0;
 layout(set = 1, binding = 1) uniform sampler2D tex;
 #else
 in vec4 fragTexCoord;
-out vec4 fragOut0;
 #ifdef COPY_ARRAY
 uniform sampler2DArray tex;
 #else
diff --git a/code/def_files/data/effects/decal-f.sdr b/code/def_files/data/effects/decal-f.sdr
index 34d65a67ba..6c1577bcd3 100644
--- a/code/def_files/data/effects/decal-f.sdr
+++ b/code/def_files/data/effects/decal-f.sdr
@@ -1,3 +1,9 @@
+#ifdef GL_ES
+precision highp float;
+precision highp int;
+precision highp sampler2D;
+precision highp sampler2DArray;
+#endif
 
 // NOTE: The technique and some of this code is based on this tutorial:
 // http://martindevans.me/game-development/2015/02/27/Drawing-Stuff-On-Other-Stuff-With-Deferred-Screenspace-Decals/
@@ -29,9 +35,14 @@ layout (set = 1, binding = 1) uniform sampler2DArray decalTextures;
 layout (set = 1, binding = 4) uniform sampler2D gDepthBuffer;
 layout (set = 1, binding = 6) uniform sampler2D gNormalBuffer;
 #else
-out vec4 fragOut0; // Diffuse buffer
-out vec4 fragOut1; // Normal buffer
-out vec4 fragOut2; // Emissive buffer
+layout (location=0) out vec4 fragOut0; // Diffuse buffer
+#ifndef GL_ES
+layout (location=1) out vec4 fragOut1; // Normal buffer
+layout (location=2) out vec4 fragOut2; // Emissive buffer
+#else
+layout (location=2) out vec4 fragOut1; // Normal buffer   -> COLOR_ATTACHMENT2
+layout (location=4) out vec4 fragOut2; // Emissive buffer -> COLOR_ATTACHMENT4
+#endif
 
 flat in mat4 invModelMatrix;
 flat in vec3 decalDirection;
@@ -124,7 +135,7 @@ vec3 getPixelNormal(vec3 frag_position, vec2 tex_coord, inout float alpha, out v
 	}
 
 	// Make a smooth alpha transition leading up to an edge
-	alpha = alpha * (1 - smoothstep(angle_fade_start, normal_angle_cutoff, angle));
+	alpha = alpha * (1.0 - smoothstep(angle_fade_start, normal_angle_cutoff, angle));
 
 	return normal;
 }
diff --git a/code/def_files/data/effects/decal-v.sdr b/code/def_files/data/effects/decal-v.sdr
index 42d9914632..46998b7983 100644
--- a/code/def_files/data/effects/decal-v.sdr
+++ b/code/def_files/data/effects/decal-v.sdr
@@ -1,3 +1,7 @@
+#ifdef GL_ES
+precision highp float;
+precision highp int;
+#endif
 
 #ifdef VULKAN
 // Binding 0: box vertex positions
diff --git a/code/def_files/data/effects/default-material-f.sdr b/code/def_files/data/effects/default-material-f.sdr
index cec7df3a76..5d8df90178 100644
--- a/code/def_files/data/effects/default-material-f.sdr
+++ b/code/def_files/data/effects/default-material-f.sdr
@@ -1,3 +1,10 @@
+#ifdef GL_ES
+#extension GL_EXT_clip_cull_distance : enable
+precision highp float;
+precision highp int;
+precision highp sampler2DArray;
+#endif
+
 #ifdef VULKAN
 layout(set = 2, binding = 0, std140)
 #else
@@ -20,22 +27,28 @@ uniform genericData {
 	uint clipEnabled;
 };
 
+layout(location = 0) out vec4 fragOut0;
+
 #ifdef VULKAN
 
 layout(set = 1, binding = 1) uniform sampler2DArray baseMap;
 
 layout(location = 0) in vec4 fragTexCoord;
 layout(location = 1) in vec4 fragColor;
-
-layout(location = 0) out vec4 fragOut0;
+#ifdef SDR_FLAG_SW_CLIP_FALLBACK
+layout(location = 2) in float vClipDist;
+#endif
 
 #else
 
+#ifdef SDR_FLAG_SW_CLIP_FALLBACK
+in float vClipDist;
+#endif
+
 uniform sampler2DArray baseMap;
 
 in vec4 fragTexCoord;
 in vec4 fragColor;
-out vec4 fragOut0;
 
 #endif
 
@@ -43,6 +56,11 @@ out vec4 fragOut0;
 
 void main()
 {
+#ifdef SDR_FLAG_SW_CLIP_FALLBACK
+	if (clipEnabled != 0u && vClipDist < 0.0) {
+		discard;
+	}
+#endif
 	vec4 baseColor = texture(baseMap, vec3(fragTexCoord.xy, float(baseMapIndex)));
 	if(alphaThreshold > baseColor.a) discard;
 	baseColor.rgb = (srgb == 1) ? srgb_to_linear(baseColor.rgb) : baseColor.rgb;
diff --git a/code/def_files/data/effects/default-material-v.sdr b/code/def_files/data/effects/default-material-v.sdr
index 902240860e..bf016f7ea4 100644
--- a/code/def_files/data/effects/default-material-v.sdr
+++ b/code/def_files/data/effects/default-material-v.sdr
@@ -1,3 +1,9 @@
+#ifdef GL_ES
+#extension GL_EXT_clip_cull_distance : enable
+precision highp float;
+precision highp int;
+#endif
+
 #ifdef VULKAN
 layout(set = 2, binding = 0, std140)
 #else
@@ -38,10 +44,15 @@ layout(location = 2) in vec4 vertTexCoord;
 
 layout(location = 0) out vec4 fragTexCoord;
 layout(location = 1) out vec4 fragColor;
+#ifdef SDR_FLAG_SW_CLIP_FALLBACK
+layout(location = 2) out float vClipDist;
+#endif
 
 #else
 
-out float gl_ClipDistance[1];
+#ifdef SDR_FLAG_SW_CLIP_FALLBACK
+out float vClipDist;
+#endif
 
 out vec4 fragTexCoord;
 in vec4 vertTexCoord;
@@ -58,13 +69,16 @@ void main()
 	gl_Position = projMatrix * modelViewMatrix * vertPosition;
 
 	if (clipEnabled != 0u) {
+		#ifndef SDR_FLAG_SW_CLIP_FALLBACK
 		gl_ClipDistance[0] = dot(clipEquation, modelMatrix * vertPosition);
+		#else
+		vClipDist = dot(clipEquation, modelMatrix * vertPosition);
+		#endif
 	} else {
-#ifdef VULKAN
-		// Vulkan has no glEnable(GL_CLIP_DISTANCE0) equivalent — clip distances are
-		// always evaluated when declared in the shader.  Must write a positive value
-		// when clipping is disabled to prevent undefined-value vertex culling.
+		#ifndef SDR_FLAG_SW_CLIP_FALLBACK
 		gl_ClipDistance[0] = 1.0;
-#endif
+		#else
+		vClipDist = 1.0;
+		#endif
 	}
 }
diff --git a/code/def_files/data/effects/deferred-clear-f.sdr b/code/def_files/data/effects/deferred-clear-f.sdr
index 4d49695ef9..3faddb831f 100644
--- a/code/def_files/data/effects/deferred-clear-f.sdr
+++ b/code/def_files/data/effects/deferred-clear-f.sdr
@@ -1,9 +1,14 @@
-out vec4 fragOut0;
-out vec4 fragOut1;
-out vec4 fragOut2;
-out vec4 fragOut3;
-out vec4 fragOut4;
-out vec4 fragOut5;
+#ifdef GL_ES
+precision highp float;
+#endif
+
+layout (location=0) out vec4 fragOut0;
+layout (location=1) out vec4 fragOut1;
+layout (location=2) out vec4 fragOut2;
+layout (location=3) out vec4 fragOut3;
+layout (location=4) out vec4 fragOut4;
+layout (location=5) out vec4 fragOut5;
+
 void main()
 {
 	fragOut0 = vec4(0.0, 0.0, 0.0, 1.0); // color
diff --git a/code/def_files/data/effects/deferred-f.sdr b/code/def_files/data/effects/deferred-f.sdr
index d5d4dba032..0ae8434b34 100644
--- a/code/def_files/data/effects/deferred-f.sdr
+++ b/code/def_files/data/effects/deferred-f.sdr
@@ -1,13 +1,21 @@
 //? #version 150
+#ifdef GL_ES
+precision highp float;
+precision highp int;
+precision highp sampler2D;
+precision highp samplerCube;
+precision highp sampler2DArrayShadow;
+#endif
+
 #include "lighting.sdr" //! #include "lighting.sdr"
 #include "gamma.sdr" //! #include "gamma.sdr"
 #include "shadows.sdr" //! #include "shadows.sdr"
 #include "z-compress.sdr" //! #include "z-compress.sdr"
 
-#ifdef VULKAN
+#ifndef GL_ES
 layout(location = 0) out vec4 fragOut0;
 #else
-out vec4 fragOut0;
+layout(location = 5) out vec4 fragOut0; //COLOR_ATTACHMENTn is on location n in ES, here it uses COLOR_ATTACHMENT5
 #endif
 
 #ifdef VULKAN
@@ -145,7 +153,7 @@ void GetLightInfo(vec3 position, in float alpha, in vec3 reflectDir, out vec3 li
 			dist = length(lightDirOut);
 			lightDist = dist;
 			// Energy conservation term
-			float alpha_adjust = clamp(alpha + (sourceRadius/(2*dist)), 0.0, 1.0);
+			float alpha_adjust = clamp(alpha + (sourceRadius/(2.0*dist)), 0.0, 1.0);
 			area_normalisation = alpha/alpha_adjust;
 			area_normalisation *= area_normalisation;
 			//end chunk
@@ -188,7 +196,7 @@ void GetLightInfo(vec3 position, in float alpha, in vec3 reflectDir, out vec3 li
 			float dist = length(lightDirOut);
 			lightDist = dist;
 			// Energy conservation term
-			float alpha_adjust = min(alpha + (sourceRadius/(2*dist)), 1.0);
+			float alpha_adjust = min(alpha + (sourceRadius/(2.0*dist)), 1.0);
 			area_normalisation = alpha/alpha_adjust;
 			// don't need to square as it's a line rather than a sphere.
 			//end chunk
@@ -235,11 +243,11 @@ void ComputeEnvLight(float alpha, float ao, vec3 light_dir, vec3 eyeDir, vec3 no
 	// so let s = (2/alpha^2 - 2)
 	// 1/2 log(s + 1) = 1/2 log(2/alpha^2 -1)
 
-	const float ENV_REZ = 512; // Ideally this would be #define'd and shader recompiled with envmap rez changes
-	const float REZ_BIAS = log2(ENV_REZ * sqrt(3));
+	const float ENV_REZ = 512.0; // Ideally this would be #define'd and shader recompiled with envmap rez changes
+	const float REZ_BIAS = log2(ENV_REZ * sqrt(3.0));
 
 	float alphaSqr = alpha * alpha;
-	float rough_bias = 0.5 * log2(2/alphaSqr - 1);
+	float rough_bias = 0.5 * log2(2.0/alphaSqr - 1.0);
 	float mip_bias = REZ_BIAS - rough_bias;
 
 	// Sample light, using mip bias to blur it.
@@ -257,7 +265,7 @@ void ComputeEnvLight(float alpha, float ao, vec3 light_dir, vec3 eyeDir, vec3 no
 	// Pseudo-IBL, so use k_IBL
 	float k = alpha * alpha/ 2.0f;
 
-	float NdotL = max(dot(light_dir, normal),0);
+	float NdotL = max(dot(light_dir, normal),0.0);
 
 	float g1vNL = GeometrySchlickGGX(NdotL, k);
 	vec3 specEnvLighting = specEnvColour.rgb * fresnel * g1vNL;
@@ -338,6 +346,6 @@ void main()
 		float NdotL = clamp(dot(normal, lightDir), 0.0, 1.0);
 		fragmentColor.rgb = computeLighting(specColor.rgb, diffColor, lightDir, normal.xyz, halfVec, eyeDir, roughness, fresnel, NdotL).rgb * diffuseLightColor * attenuation * area_normalisation;
 	}
-
+	
 	fragOut0 = max(fragmentColor, vec4(0.0));
 }
diff --git a/code/def_files/data/effects/deferred-v.sdr b/code/def_files/data/effects/deferred-v.sdr
index 2c9d4b02c6..98fa87d7f6 100644
--- a/code/def_files/data/effects/deferred-v.sdr
+++ b/code/def_files/data/effects/deferred-v.sdr
@@ -1,3 +1,7 @@
+#ifdef GL_ES
+precision highp float;
+precision highp int;
+#endif
 
 #include "lighting.sdr"
 
diff --git a/code/def_files/data/effects/effect-distort-f.sdr b/code/def_files/data/effects/effect-distort-f.sdr
index b43907a39d..d06ff7409d 100644
--- a/code/def_files/data/effects/effect-distort-f.sdr
+++ b/code/def_files/data/effects/effect-distort-f.sdr
@@ -1,10 +1,16 @@
+#ifdef GL_ES
+precision highp float;
+precision highp sampler2D;
+precision highp sampler2DArray;
+#endif
+
+layout(location = 0) out vec4 fragOut0;
+
 #ifdef VULKAN
 layout(location = 0) in vec4 fragTexCoord;
 layout(location = 1) in vec4 fragColor;
 layout(location = 2) in float fragOffset;
 
-layout(location = 0) out vec4 fragOut0;
-
 layout(set = 1, binding = 1) uniform sampler2DArray baseMap;
 layout(set = 1, binding = 4) uniform sampler2D depthMap;
 layout(set = 1, binding = 5) uniform sampler2D frameBuffer;
@@ -14,8 +20,6 @@ in vec4 fragTexCoord;
 in vec4 fragColor;
 in float fragOffset;
 
-out vec4 fragOut0;
-
 uniform sampler2DArray baseMap;
 uniform sampler2D depthMap;
 uniform sampler2D distMap;
diff --git a/code/def_files/data/effects/effect-distort-v.sdr b/code/def_files/data/effects/effect-distort-v.sdr
index 5673b1baf3..2eb075be1d 100644
--- a/code/def_files/data/effects/effect-distort-v.sdr
+++ b/code/def_files/data/effects/effect-distort-v.sdr
@@ -1,3 +1,7 @@
+#ifdef GL_ES
+precision highp float;
+#endif
+
 #ifdef VULKAN
 layout(location = 0) in vec4 vertPosition;
 layout(location = 1) in vec4 vertColor;
diff --git a/code/def_files/data/effects/effect-f.sdr b/code/def_files/data/effects/effect-f.sdr
index f46147830e..b8a73fbef8 100644
--- a/code/def_files/data/effects/effect-f.sdr
+++ b/code/def_files/data/effects/effect-f.sdr
@@ -1,15 +1,21 @@
+#ifdef GL_ES
+precision highp float;
+precision highp int;
+precision highp sampler2D;
+precision highp sampler2DArray;
+#endif
 
 #include "gamma.sdr"
 #include "z-compress.sdr"
 
+layout(location = 0) out vec4 fragOut0;
+
 #ifdef VULKAN
 layout(location = 0) in vec4 fragTexCoord;
 layout(location = 1) in vec4 fragColor;
 layout(location = 2) in float fragRadius;
 layout(location = 3) in vec4 fragPosition;
 
-layout(location = 0) out vec4 fragOut0;
-
 layout(set = 1, binding = 1) uniform sampler2DArray baseMap;
 layout(set = 1, binding = 4) uniform sampler2D depthMap;
 #else
@@ -18,8 +24,6 @@ in vec4 fragPosition;
 in vec4 fragTexCoord;
 in vec4 fragColor;
 
-out vec4 fragOut0;
-
 uniform sampler2DArray baseMap;
 uniform sampler2D depthMap;
 #endif
diff --git a/code/def_files/data/effects/effect-g.sdr b/code/def_files/data/effects/effect-g.sdr
index d1cb231129..44e8545ee7 100644
--- a/code/def_files/data/effects/effect-g.sdr
+++ b/code/def_files/data/effects/effect-g.sdr
@@ -1,3 +1,7 @@
+#ifdef GL_ES
+precision highp float;
+#endif
+
 layout (points) in;
 layout (triangle_strip, max_vertices = 4) out;
 
diff --git a/code/def_files/data/effects/effect-v.sdr b/code/def_files/data/effects/effect-v.sdr
index 86244a7ee8..3662e9e864 100644
--- a/code/def_files/data/effects/effect-v.sdr
+++ b/code/def_files/data/effects/effect-v.sdr
@@ -1,3 +1,6 @@
+#ifdef GL_ES
+precision highp float;
+#endif
 
 #ifdef VULKAN
 layout(location = 0) in vec4 vertPosition;
diff --git a/code/def_files/data/effects/envmap-sphere-warp-f.sdr b/code/def_files/data/effects/envmap-sphere-warp-f.sdr
index ab2b407161..8cc562e693 100644
--- a/code/def_files/data/effects/envmap-sphere-warp-f.sdr
+++ b/code/def_files/data/effects/envmap-sphere-warp-f.sdr
@@ -1,11 +1,14 @@
 #define M_PI 3.1415926535897932384626433832795
+#ifdef GL_ES
+precision highp float;
+precision highp samplerCube;
+#endif
+
 uniform samplerCube envmap;
 
 in vec4 fragTexCoord;
 
-out vec4 fragOut0;
-
-layout (location = 0) out vec4 outColor;
+layout(location=0) out vec4 fragOut0;
 
 void main() {
 	const float theta = -fragTexCoord.x * (2.0 * M_PI);
diff --git a/code/def_files/data/effects/fog-f.sdr b/code/def_files/data/effects/fog-f.sdr
index 6c822bb67e..c252e91b61 100644
--- a/code/def_files/data/effects/fog-f.sdr
+++ b/code/def_files/data/effects/fog-f.sdr
@@ -1,17 +1,20 @@
+#ifdef GL_ES
+precision highp float;
+precision highp sampler2D;
+#endif
 
 #include "gamma.sdr"
 
+layout(location=0) out vec4 fragOut0;
+
 #ifdef VULKAN
 layout(location = 0) in vec2 fragTexCoord;
-layout(location = 0) out vec4 fragOut0;
 
 layout(set = 1, binding = 1) uniform sampler2D tex;
 layout(set = 1, binding = 4) uniform sampler2D depth_tex;
 #else
 in vec4 fragTexCoord;
 
-out vec4 fragOut0;
-
 uniform sampler2D tex;
 uniform sampler2D depth_tex;
 #endif
@@ -40,7 +43,7 @@ void main()
 	// If the scene is in fog then we change the color we operate on based on the depth of the pixel
 	float depth_val = texture(depth_tex, fragTexCoord.xy).x;
 	// Transform depth value from [0, 1] to [-1, 1]
-	float depth_normalized = 2 * depth_val - 1;
+	float depth_normalized = 2.0 * depth_val - 1.0;
 	// Now we compute the depth value in projection space using the clipping plane information
 	float view_depth = 2.0 * zNear * zFar / (zFar + zNear - depth_normalized * (zFar - zNear));
 
@@ -50,7 +53,7 @@ void main()
 	if (isinf(view_depth)) {
 		fragOut0.rgb = color_in.rgb;
 	} else {
-		float fog_dist = clamp(1 - pow(fog_density, view_depth - fog_start) , 0.0, 1.0);
+		float fog_dist = clamp(1.0 - pow(fog_density, view_depth - fog_start) , 0.0, 1.0);
 		vec3 finalFogColor = srgb_to_linear(fog_color);
 
 		fragOut0.rgb = mix(color_in.rgb, finalFogColor, fog_dist);
diff --git a/code/def_files/data/effects/fxaa-f.sdr b/code/def_files/data/effects/fxaa-f.sdr
index 329b68384b..0cd59026d2 100644
--- a/code/def_files/data/effects/fxaa-f.sdr
+++ b/code/def_files/data/effects/fxaa-f.sdr
@@ -1,3 +1,12 @@
+#ifdef GL_ES
+#ifdef GL_EXT_gpu_shader5
+	#extension GL_EXT_gpu_shader5 : enable
+	#define FXAA_GATHER4_ALPHA 1
+#endif
+precision highp float;
+precision highp sampler2D;
+#endif
+
 #define FXAA_EARLY_EXIT 1
 #define FXAA_DISCARD 1
 #define FXAA_FAST_PIXEL_OFFSET 1 // With OpenGL 3.2 we can always do this
@@ -500,8 +509,12 @@ layout(std140, set = 2, binding = 0) uniform genericData {
 #else
 uniform sampler2D tex0;
 in vec2 v_rcpFrame;
+#ifdef GL_ES
+in vec2 v_pos;
+#else
 noperspective in vec2 v_pos;
-out vec4 fragOut0;
+#endif
+layout(location=0)out vec4 fragOut0;
 #endif
 
 void main() {
diff --git a/code/def_files/data/effects/fxaa-v.sdr b/code/def_files/data/effects/fxaa-v.sdr
index 22a9053f2a..fa5bc259b2 100644
--- a/code/def_files/data/effects/fxaa-v.sdr
+++ b/code/def_files/data/effects/fxaa-v.sdr
@@ -1,3 +1,6 @@
+#ifdef GL_ES
+precision highp float;
+#endif
 
 #ifdef VULKAN
 layout(location = 0) out vec2 fragTexCoord;
@@ -10,7 +13,11 @@ void main() {
 in vec4 vertPosition;
 
 out vec2 v_rcpFrame;
+#ifdef GL_ES
+out vec2 v_pos;
+#else
 noperspective out vec2 v_pos;
+#endif
 
 layout (std140) uniform genericData {
 	float rt_w;
diff --git a/code/def_files/data/effects/fxaapre-f.sdr b/code/def_files/data/effects/fxaapre-f.sdr
index 64dd348734..a9f6c03c50 100644
--- a/code/def_files/data/effects/fxaapre-f.sdr
+++ b/code/def_files/data/effects/fxaapre-f.sdr
@@ -1,6 +1,12 @@
+#ifdef GL_ES
+precision highp float;
+precision highp sampler2D;
+#endif
+
+layout(location=0) out vec4 fragOut0;
+
 #ifdef VULKAN
 layout(location = 0) in vec2 fragTexCoord;
-layout(location = 0) out vec4 fragOut0;
 // [0]=real color (passed through as-is), [1]=luma detection proxy (see
 // getAADetectionView; may be the same view as [0] when not HDR)
 layout(set = 1, binding = 1) uniform sampler2D fxaaTex[2];
@@ -8,9 +14,9 @@ layout(set = 1, binding = 1) uniform sampler2D fxaaTex[2];
 #define lumaTex fxaaTex[1]
 #else
 in vec4 fragTexCoord;
-out vec4 fragOut0;
 uniform sampler2D tex;
 #endif
+
 void main() {
 	vec4 color = texture(tex, fragTexCoord.xy);
 #ifdef VULKAN
diff --git a/code/def_files/data/effects/gamma-correct-f.sdr b/code/def_files/data/effects/gamma-correct-f.sdr
index dc6ec53425..2f5201fcd1 100644
--- a/code/def_files/data/effects/gamma-correct-f.sdr
+++ b/code/def_files/data/effects/gamma-correct-f.sdr
@@ -1,12 +1,17 @@
+#ifdef GL_ES
+precision highp float;
+precision highp sampler2D;
+#endif
+
 #include "gamma.sdr"
 
+layout(location=0)out vec4 fragOut0;
+
 #ifdef VULKAN
 layout(location = 0) in vec2 fragTexCoord;
-layout(location = 0) out vec4 fragOut0;
 layout(set = 1, binding = 1) uniform sampler2D tex;
 #else
 in vec4 fragTexCoord;
-out vec4 fragOut0;
 uniform sampler2D tex;
 #endif
 
diff --git a/code/def_files/data/effects/gamma.sdr b/code/def_files/data/effects/gamma.sdr
index a57ce437bd..7067fef93b 100644
--- a/code/def_files/data/effects/gamma.sdr
+++ b/code/def_files/data/effects/gamma.sdr
@@ -1,3 +1,6 @@
+#ifdef GL_ES
+precision highp float;
+#endif
 
 const float SRGB_GAMMA = 2.2;
 const float SRGB_GAMMA_INVERSE = 1.0 / SRGB_GAMMA;
diff --git a/code/def_files/data/effects/irrmap-f.sdr b/code/def_files/data/effects/irrmap-f.sdr
index 556480d22e..ea07011469 100644
--- a/code/def_files/data/effects/irrmap-f.sdr
+++ b/code/def_files/data/effects/irrmap-f.sdr
@@ -1,15 +1,21 @@
 //!#version 150
-#include "gamma.sdr" //! #include "gamma.sdr"
+#ifdef GL_ES
+precision highp float;
+precision highp int;
+precision highp samplerCube;
+#endif
+
+#include "gamma.sdr"
 #define PI 3.1415926535897932384626433832795
 
+layout(location = 0) out vec4 fragOut0;
+
 #ifdef VULKAN
 layout(location = 0) in vec2 fragTexCoord;
-layout(location = 0) out vec4 fragOut0;
 layout(set = 1, binding = 1) uniform samplerCube envmap;
 #else
 uniform samplerCube envmap;
 in vec4 fragTexCoord;
-out vec4 fragOut0;
 #endif
 
 #ifdef VULKAN
@@ -154,8 +160,8 @@ vec3( 0.7305,  0.6698,  0.1333)
 );
 
 void main() {
-	float xpos = 2 * gl_FragCoord.x/16 - 1; // remap to (-1, 1)
-	float ypos = 2 * gl_FragCoord.y/16 - 1;
+	float xpos = 2.0 * gl_FragCoord.x/16.0 - 1.0; // remap to (-1, 1)
+	float ypos = 2.0 * gl_FragCoord.y/16.0 - 1.0;
 	vec3 fragDir;
 	vec4 fragCol = vec4(0.0);
 
@@ -191,5 +197,5 @@ void main() {
 		vec3 sampDir = points[i] + (aPdotD - PdotD) * fragDir;
 		fragCol += aPdotD * vec4(srgb_to_linear(texture(envmap, sampDir)).rgb, 1.0);
 	}
-	fragOut0 = linear_to_srgb(PI * fragCol * (1.0/128));
+	fragOut0 = linear_to_srgb(PI * fragCol * (1.0/128.0));
 }
\ No newline at end of file
diff --git a/code/def_files/data/effects/lighting.sdr b/code/def_files/data/effects/lighting.sdr
index 799617b52e..2166b61de7 100644
--- a/code/def_files/data/effects/lighting.sdr
+++ b/code/def_files/data/effects/lighting.sdr
@@ -57,7 +57,7 @@ vec3 ComputeGGX(vec3 specColor, vec3 diffColor, vec3 light, vec3 normal, vec3 ha
 
 
 
-	vec3 specular = distribution * fresnel * geometry / (4*dotNV*dotNL + 0.0001);
+	vec3 specular = distribution * fresnel * geometry / (4.0*dotNV*dotNL + 0.0001);
 	
 	// Diffuse term - Lambertian, kD represents energy lost to specular reflection.
 	vec3 kD = vec3(1.0)-fresnel;
@@ -70,7 +70,7 @@ vec3 ComputeGGX(vec3 specColor, vec3 diffColor, vec3 light, vec3 normal, vec3 ha
 vec3 computeLighting(vec3 specColor, vec3 diffColor, vec3 light, vec3 normal, vec3 halfVec, vec3 view, float roughness, float fresnelFactor, float dotNL) 
 {
 	#ifdef FLAG_LIGHT_MODEL_BLINN_PHONG
-	return SpecularBlinnPhong(specColor, light, normal, halfVec, 32, fresnelFactor, dotNL);
+	return SpecularBlinnPhong(specColor, light, normal, halfVec, 32.0, fresnelFactor, dotNL);
 	#else
 	return ComputeGGX(specColor, diffColor, light, normal, halfVec, view, roughness, fresnelFactor, dotNL);
 	#endif
diff --git a/code/def_files/data/effects/ls-f.sdr b/code/def_files/data/effects/ls-f.sdr
index cc4ff755da..694ed7f454 100644
--- a/code/def_files/data/effects/ls-f.sdr
+++ b/code/def_files/data/effects/ls-f.sdr
@@ -1,7 +1,14 @@
+#ifdef GL_ES
+precision highp float;
+precision highp int;
+precision highp sampler2D;
+#endif
+
+layout(location = 0) out vec4 fragOut0;
 
 #ifdef VULKAN
 layout(location = 0) in vec2 fragTexCoord;
-layout(location = 0) out vec4 fragOut0;
+
 
 layout(set = 1, binding = 1) uniform sampler2D textures[16];
 #define scene textures[0]
@@ -9,8 +16,6 @@ layout(set = 1, binding = 1) uniform sampler2D textures[16];
 #else
 in vec4 fragTexCoord;
 
-out vec4 fragOut0;
-
 uniform sampler2D scene;
 uniform sampler2D cockpit;
 #endif
diff --git a/code/def_files/data/effects/main-f.sdr b/code/def_files/data/effects/main-f.sdr
index 746fe0973b..5b2beb5d91 100644
--- a/code/def_files/data/effects/main-f.sdr
+++ b/code/def_files/data/effects/main-f.sdr
@@ -1,4 +1,13 @@
 //? #version 150
+#ifdef GL_ES
+#extension GL_EXT_clip_cull_distance: enable
+precision highp float;
+precision highp int;
+precision highp sampler2D;
+precision highp sampler2DArray;
+precision highp sampler2DArrayShadow;
+#endif
+
 #include "shadows.sdr" //! #include "shadows.sdr"
 #include "lighting.sdr" //! #include "lighting.sdr"
 #include "gamma.sdr" //! #include "gamma.sdr"
@@ -112,6 +121,13 @@ uniform shadowCascadeParams {
 	vec4 smoothness_factors[(NUM_SHADOW_CASCADES + 4 - 1) / 4];
 };
 
+
+layout(location = 0) out vec4 fragOut0;
+layout(location = 1) out vec4 fragOut1;
+layout(location = 2) out vec4 fragOut2;
+layout(location = 3) out vec4 fragOut3;
+layout(location = 4) out vec4 fragOut4;
+
 #ifdef VULKAN
 layout(set = 1, binding = 1) uniform sampler2DArray materialTextures[16];
 #define sBasemap materialTextures[0]
@@ -139,13 +155,12 @@ layout(location = 0) in VertexOutput {
 	vec4 shadowUV[NUM_SHADOW_CASCADES];
 	vec4 shadowPos;
 #prereplace ENDIF_FLAG_COMPILED MODEL_SDR_FLAG_SHADOWS
+
+#ifdef SDR_FLAG_SW_CLIP_FALLBACK
+    float vClipDist;
+#endif
 } vertIn;
 
-layout(location = 0) out vec4 fragOut0;
-layout(location = 1) out vec4 fragOut1;
-layout(location = 2) out vec4 fragOut2;
-layout(location = 3) out vec4 fragOut3;
-layout(location = 4) out vec4 fragOut4;
 #else
 #prereplace IF_FLAG_COMPILED MODEL_SDR_FLAG_DIFFUSE
 uniform sampler2DArray sBasemap;
@@ -185,13 +200,10 @@ in VertexOutput {
 	vec4 shadowUV[NUM_SHADOW_CASCADES];
 	vec4 shadowPos;
 #prereplace ENDIF_FLAG_COMPILED MODEL_SDR_FLAG_SHADOWS
+#ifdef SDR_FLAG_SW_CLIP_FALLBACK
+    float vClipDist;
+#endif
 } vertIn;
-
-out vec4 fragOut0;
-out vec4 fragOut1;
-out vec4 fragOut2;
-out vec4 fragOut3;
-out vec4 fragOut4;
 #endif
 
 vec3 FresnelLazarovEnv(vec3 specColor, vec3 view, vec3 normal, float gloss)
@@ -283,6 +295,10 @@ vec3 CalculateLighting(vec3 normal, vec3 diffuseMaterial, vec3 specularMaterial,
 
 void main()
 {
+	#ifdef SDR_FLAG_SW_CLIP_FALLBACK
+		if (vertIn.vClipDist < 0.0) discard;
+	#endif
+
 	vec3 eyeDir = vec3(normalize(-vertIn.position).xyz);
 	vec2 texCoord = vertIn.texCoord.xy;
 
@@ -464,7 +480,7 @@ void main()
 		#prereplace ENDIF_FLAG //MODEL_SDR_FLAG_DIFFUSE
 		// This code will only be used by the forward renderer so we apply the fog effect to both the emissive and the base
 		// color.
-		float fogDensityFinal = clamp(1 - pow(fogDensity, vertIn.fogDist) , 0.0, 1.0);
+		float fogDensityFinal = clamp(1.0 - pow(fogDensity, vertIn.fogDist) , 0.0, 1.0);
 		baseColor.rgb = mix(emissiveColor.rgb + baseColor.rgb, finalFogColor, fogDensityFinal);
 		emissiveColor.rgb = vec3(0.0); // Zero the emissive color since it has already been added by the previous line
 		specColor.rgb *= fogDensityFinal;
@@ -509,11 +525,12 @@ void main()
 		#prereplace IF_NOT_FLAG MODEL_SDR_FLAG_LIGHT
 			#prereplace IF_FLAG MODEL_SDR_FLAG_SPEC
 				baseColor.rgb += pow(1.0 - clamp(dot(eyeDir, normal), 0.0, 1.0), 5.0 * clamp(glossData, 0.01, 1.0)) * specColor.rgb;
-				glossData = 0;
+				glossData = 0.0f;
 			#prereplace ENDIF_FLAG //MODEL_SDR_FLAG_SPEC
 			// If there is no lighting then we copy the color data so far into the emissive.
 			emissiveColor.rgb += baseColor.rgb;
-			aoFactors.x = 0;
+
+			aoFactors.x = 0.0f;
 			// and leave nothing for the light pass to add on top of it
 			baseColor.rgb = vec3(0.0);
 			specColor = vec4(0.0);
diff --git a/code/def_files/data/effects/main-g.sdr b/code/def_files/data/effects/main-g.sdr
index e348c386df..4c288fa4d4 100644
--- a/code/def_files/data/effects/main-g.sdr
+++ b/code/def_files/data/effects/main-g.sdr
@@ -1,4 +1,11 @@
+#ifdef GL_ES
+#extension GL_EXT_gpu_shader5: enable
+#extension GL_EXT_clip_cull_distance: enable
+precision highp float;
+precision highp int;
+#else
 #extension GL_ARB_gpu_shader5: enable
+#endif
 
 #conditional_include +"LARGE_SHADER" "main_large.sdr"
 #conditional_include -"LARGE_SHADER" "main_small.sdr"
@@ -100,6 +107,9 @@ in VertexOutput {
 	vec4 shadowUV[NUM_SHADOW_CASCADES];
 	vec4 shadowPos;
 #prereplace ENDIF_FLAG_COMPILED MODEL_SDR_FLAG_SHADOWS
+#ifdef SDR_FLAG_SW_CLIP_FALLBACK
+    float vClipDist;
+#endif
 } vertIn[];
 
 out VertexOutput {
@@ -117,6 +127,10 @@ out VertexOutput {
 	vec4 shadowUV[NUM_SHADOW_CASCADES];
 	vec4 shadowPos;
 #prereplace ENDIF_FLAG_COMPILED MODEL_SDR_FLAG_SHADOWS
+
+#ifdef SDR_FLAG_SW_CLIP_FALLBACK
+    float vClipDist;
+#endif
 } vertOut;
 
 #ifdef MODEL_SDR_FLAG_THICK_OUTLINES
@@ -166,8 +180,19 @@ out VertexOutput {
                 #prereplace ENDIF_FLAG //MODEL_SDR_FLAG_SHADOWS
 
 				if (use_clip_plane != 0) {
-					gl_ClipDistance[0] = gl_in[vert].gl_ClipDistance[0];
+					#ifdef SDR_FLAG_SW_CLIP_FALLBACK
+						vertOut.vClipDist = vertIn[vert].vClipDist;
+					#else
+						gl_ClipDistance[0] = gl_in[vert].gl_ClipDistance[0];
+					#endif
+				} else {
+					#ifdef SDR_FLAG_SW_CLIP_FALLBACK
+						vertOut.vClipDist = 1.0;
+					#else
+						gl_ClipDistance[0] = 1.0;
+					#endif
 				}
+
 				EmitVertex();
 			}
 
diff --git a/code/def_files/data/effects/main-v.sdr b/code/def_files/data/effects/main-v.sdr
index a0adda205a..3dbe2cd77e 100644
--- a/code/def_files/data/effects/main-v.sdr
+++ b/code/def_files/data/effects/main-v.sdr
@@ -1,8 +1,18 @@
 
 #ifndef VULKAN
 //? #version 150
+#ifdef GL_ES
+#extension GL_EXT_gpu_shader5: enable
+#extension GL_EXT_clip_cull_distance: enable
+precision highp float;
+precision highp int;
+precision highp samplerBuffer;
+precision highp sampler2DArrayShadow;
+#else
 #extension GL_ARB_gpu_shader5: enable
 #endif
+#endif
+
 #include "shadows.sdr"
 
 #conditional_include +"LARGE_SHADER" "main_large.sdr"
@@ -145,6 +155,10 @@ layout(location = 0) out VertexOutput {
 	vec4 shadowUV[NUM_SHADOW_CASCADES];
 	vec4 shadowPos;
 #prereplace ENDIF_FLAG_COMPILED MODEL_SDR_FLAG_SHADOWS
+
+#ifdef SDR_FLAG_SW_CLIP_FALLBACK
+    float vClipDist;
+#endif
 } vertOut;
 #else
 #prereplace IF_FLAG_COMPILED MODEL_SDR_FLAG_TRANSFORM
@@ -166,6 +180,10 @@ out VertexOutput {
 	vec4 shadowUV[NUM_SHADOW_CASCADES];
 	vec4 shadowPos;
 #prereplace ENDIF_FLAG_COMPILED MODEL_SDR_FLAG_SHADOWS
+
+#ifdef SDR_FLAG_SW_CLIP_FALLBACK
+    float vClipDist;
+#endif
 } vertOut;
 
 #define TEXELS_PER_MATRIX 4
@@ -247,12 +265,20 @@ void main()
 		}
 	#prereplace ENDIF_FLAG //MODEL_SDR_FLAG_TRANSFORM
 
-	// Clip plane
-	if(use_clip_plane != 0) {
-		gl_ClipDistance[0] = dot(clip_equation, modelMatrix * orient * vertex);
-	} else {
-		gl_ClipDistance[0] = 1.0;
-	}
+	#ifndef SDR_FLAG_SW_CLIP_FALLBACK
+		if (use_clip_plane != 0) {
+			gl_ClipDistance[0] = dot(clip_equation, modelMatrix * orient * vertex);
+		} else {
+			gl_ClipDistance[0] = 1.0;
+		}
+	#else
+		if (use_clip_plane != 0) {
+			vertOut.vClipDist = dot(clip_equation, modelMatrix * orient * vertex);
+		} else {
+			vertOut.vClipDist = 1.0;
+		}
+	#endif
+
 
 	vertOut.position = position;
 	vertOut.normal = normal;
diff --git a/code/def_files/data/effects/msaa-f.sdr b/code/def_files/data/effects/msaa-f.sdr
index 85ce8d36af..ddee352792 100644
--- a/code/def_files/data/effects/msaa-f.sdr
+++ b/code/def_files/data/effects/msaa-f.sdr
@@ -1,7 +1,10 @@
-#include "z-compress.sdr"
+#ifdef GL_ES
+precision highp float;
+precision highp int;
+precision highp sampler2DMS;
+#endif
 
-#ifdef VULKAN
-layout(location = 0) in vec2 fragTexCoord;
+#include "z-compress.sdr"
 
 layout(location = 0) out vec4 fragOut0;
 layout(location = 1) out vec4 fragOut1;
@@ -9,6 +12,9 @@ layout(location = 2) out vec4 fragOut2;
 layout(location = 3) out vec4 fragOut3;
 layout(location = 4) out vec4 fragOut4;
 
+#ifdef VULKAN
+layout(location = 0) in vec2 fragTexCoord;
+
 layout(set = 1, binding = 1) uniform sampler2DMS msaaTex[6];
 #define texColor    msaaTex[0]
 #define texPos      msaaTex[1]
@@ -23,12 +29,7 @@ layout(std140, set = 2, binding = 0) uniform genericData {
 };
 #else
 in vec4 fragTexCoord;
-out vec4 fragOut0;
-out vec4 fragOut1;
-out vec4 fragOut2;
-out vec4 fragOut3;
-out vec4 fragOut4;
-out vec4 fragOut5;
+layout(location=5)out vec4 fragOut5;
 
 uniform sampler2DMS texColor;
 uniform sampler2DMS texPos;
@@ -176,7 +177,7 @@ float getMedianDist(ivec2 texel) {
 
 //Fallback, do front first
 float getMedianDist(ivec2 texel) {
-	float minDist = -1000000;
+	float minDist = -1000000.0;
 	for(int i = 0; i < samples; i++) {
 		minDist = max(minDist, uncompress_depth_value(texelFetch(texPos, texel, i).z));
 	}
@@ -190,7 +191,7 @@ float getMedianDist(ivec2 texel) {
 
 void main()
 {
-	vec2 texSize = textureSize(texColor);
+	vec2 texSize = vec2(textureSize(texColor));
 #ifdef VULKAN
 	ivec2 texel = ivec2(texSize * fragTexCoord);
 #else
@@ -206,7 +207,7 @@ void main()
 	vec4 normal = vec4(0);
 	vec4 specular = vec4(0);
 	vec4 emissive = vec4(0);
-	float depth = 0;
+	float depth = 0.0;
 
 	for(int i = 0; i < SAMPLE_CNT; i++) {
 		vec4 localPos = texelFetch(texPos, texel, i);
diff --git a/code/def_files/data/effects/nanovg-f.sdr b/code/def_files/data/effects/nanovg-f.sdr
index dbe4170306..4ba74a86c9 100644
--- a/code/def_files/data/effects/nanovg-f.sdr
+++ b/code/def_files/data/effects/nanovg-f.sdr
@@ -1,3 +1,8 @@
+#ifdef GL_ES
+precision highp float;
+precision highp int;
+precision highp sampler2DArray;
+#endif
 
 #ifdef VULKAN
 layout (location = 0) in vec2 ftcoord;
diff --git a/code/def_files/data/effects/nanovg-v.sdr b/code/def_files/data/effects/nanovg-v.sdr
index 2974de708e..89a56d5a4c 100644
--- a/code/def_files/data/effects/nanovg-v.sdr
+++ b/code/def_files/data/effects/nanovg-v.sdr
@@ -1,3 +1,7 @@
+#ifdef GL_ES
+precision highp float;
+precision highp int;
+#endif
 
 #ifdef VULKAN
 layout (location = 0) in vec4 vertPosition;
diff --git a/code/def_files/data/effects/normals.sdr b/code/def_files/data/effects/normals.sdr
index 8123bd1374..185dc5cbff 100644
--- a/code/def_files/data/effects/normals.sdr
+++ b/code/def_files/data/effects/normals.sdr
@@ -7,6 +7,6 @@
 vec3 unpackNormal(vec2 normal_sample) {
 	vec3 normal;
 	normal.xy = normal_sample * 2.0 - 1.0;
-	normal.z = sqrt(1 - normal_sample.x * normal_sample.x - normal_sample.y * normal_sample.y);
+	normal.z = sqrt(1.0 - normal_sample.x * normal_sample.x - normal_sample.y * normal_sample.y);
 	return normal;
 }
diff --git a/code/def_files/data/effects/passthrough-f.sdr b/code/def_files/data/effects/passthrough-f.sdr
index 6e3134e068..3b06379b9b 100644
--- a/code/def_files/data/effects/passthrough-f.sdr
+++ b/code/def_files/data/effects/passthrough-f.sdr
@@ -1,9 +1,14 @@
+#ifdef GL_ES
+precision highp float;
+precision highp int;
+precision highp sampler2D;
+#endif
 
 #include "gamma.sdr"
 
 in vec4 fragTexCoord;
 in vec4 fragColor;
-out vec4 fragOut0;
+layout(location=0) out vec4 fragOut0;
 
 uniform sampler2D baseMap;
 
diff --git a/code/def_files/data/effects/post-f.sdr b/code/def_files/data/effects/post-f.sdr
index 6e12a5e20f..29bc2a78ae 100644
--- a/code/def_files/data/effects/post-f.sdr
+++ b/code/def_files/data/effects/post-f.sdr
@@ -1,11 +1,16 @@
+#ifdef GL_ES
+precision highp float;
+precision highp sampler2D;
+#endif
+
+layout(location = 0) out vec4 fragOut0;
+
 #ifdef VULKAN
 layout(location = 0) in vec2 fragTexCoord;
-layout(location = 0) out vec4 fragOut0;
 layout(set = 1, binding = 1) uniform sampler2D tex;
 layout(set = 1, binding = 4) uniform sampler2D depth_tex;
 #else
 in vec4 fragTexCoord;
-out vec4 fragOut0;
 uniform sampler2D tex;
 uniform sampler2D depth_tex;
 #endif
diff --git a/code/def_files/data/effects/rocketui-f.sdr b/code/def_files/data/effects/rocketui-f.sdr
index 688d2ec5fe..a3559ab4b8 100644
--- a/code/def_files/data/effects/rocketui-f.sdr
+++ b/code/def_files/data/effects/rocketui-f.sdr
@@ -1,10 +1,17 @@
+#ifdef GL_ES
+precision highp float;
+precision highp int;
+precision highp sampler2DArray;
+#endif
+
+layout(location = 0) out vec4 fragOut0;
 
 #ifdef VULKAN
 layout(location = 0) in vec2 fragTexCoord;
 layout(location = 1) in vec4 fragColor;
 layout(location = 2) in vec2 fragScreenPosition;
 
-layout(location = 0) out vec4 fragOut0;
+
 
 layout(set = 1, binding = 1) uniform sampler2DArray baseMap;
 #else
@@ -12,8 +19,6 @@ in vec2 fragTexCoord;
 in vec4 fragColor;
 in vec2 fragScreenPosition;
 
-out vec4 fragOut0;
-
 uniform sampler2DArray baseMap;
 #endif
 
diff --git a/code/def_files/data/effects/rocketui-v.sdr b/code/def_files/data/effects/rocketui-v.sdr
index 07ae245966..df966d8a1d 100644
--- a/code/def_files/data/effects/rocketui-v.sdr
+++ b/code/def_files/data/effects/rocketui-v.sdr
@@ -1,3 +1,7 @@
+#ifdef GL_ES
+precision highp float;
+precision highp int;
+#endif
 
 #ifdef VULKAN
 layout(location = 0) in vec2 vertPosition;
diff --git a/code/def_files/data/effects/shadow_map-f.sdr b/code/def_files/data/effects/shadow_map-f.sdr
index fff405831f..23067e898a 100644
--- a/code/def_files/data/effects/shadow_map-f.sdr
+++ b/code/def_files/data/effects/shadow_map-f.sdr
@@ -1,5 +1,24 @@
 //? #version 150
+#ifdef GL_ES
+#extension GL_EXT_clip_cull_distance: enable
+precision highp float;
+#endif
+
+#ifdef SDR_FLAG_SW_CLIP_FALLBACK
+#ifdef VULKAN
+layout(location = 0) in VertexOutput {
+	float vClipDist;
+} vertIn;
+#else
+in VertexOutput {
+	float vClipDist;
+} vertIn;
+#endif
+#endif
 
 void main()
 {
+#ifdef SDR_FLAG_SW_CLIP_FALLBACK
+	if (vertIn.vClipDist < 0.0) discard;
+#endif
 }
diff --git a/code/def_files/data/effects/shadow_map-g.sdr b/code/def_files/data/effects/shadow_map-g.sdr
index 6375b79300..4b196e9463 100644
--- a/code/def_files/data/effects/shadow_map-g.sdr
+++ b/code/def_files/data/effects/shadow_map-g.sdr
@@ -1,9 +1,16 @@
 //? #version 150
+#ifdef GL_ES
+#extension GL_EXT_gpu_shader5: enable
+#extension GL_EXT_clip_cull_distance: enable
+precision highp float;
+precision highp int;
+#else
 #extension GL_ARB_gpu_shader5: enable
+#endif
 
 layout (triangles) in;
 layout (triangle_strip, max_vertices = 3) out;
-#ifdef GL_ARB_gpu_shader5
+#if defined(GL_ARB_gpu_shader5) || defined(GL_EXT_gpu_shader5)
 layout(invocations = NUM_SHADOW_CASCADES) in;
 #endif
 
@@ -24,16 +31,25 @@ layout (std140) uniform shadowCascadeParams {
 };
 
 in VertexOutput {
-#if !defined(GL_ARB_gpu_shader5)
+#if !defined(GL_ARB_gpu_shader5) && !defined(GL_EXT_gpu_shader5)
     float instance;
 #endif
 	float clipModel;
 	vec3 normal;
+#ifdef SDR_FLAG_SW_CLIP_FALLBACK
+	float vClipDist;
+#endif
 } vertIn[];
 
+#ifdef SDR_FLAG_SW_CLIP_FALLBACK
+out VertexOutput {
+	float vClipDist;
+} vertOut;
+#endif
+
 void main(void)
 {
-#ifdef GL_ARB_gpu_shader5
+#if defined(GL_ARB_gpu_shader5) || defined(GL_EXT_gpu_shader5)
     if (gl_InvocationID >= cascade_count) return;
     int cascade_id = cascade_offset + gl_InvocationID;
 #else
@@ -49,7 +65,12 @@ void main(void)
 		}
 
 		gl_Layer = cascade_id;
-		gl_ClipDistance[0] = gl_in[vert].gl_ClipDistance[0];
+		
+		#ifdef SDR_FLAG_SW_CLIP_FALLBACK
+			vertOut.vClipDist = vertIn[vert].vClipDist;
+		#else
+			gl_ClipDistance[0] = gl_in[vert].gl_ClipDistance[0];
+		#endif
 
 		EmitVertex();
 	}
diff --git a/code/def_files/data/effects/shadow_map-v.sdr b/code/def_files/data/effects/shadow_map-v.sdr
index 736ff37f16..3d846ad3af 100644
--- a/code/def_files/data/effects/shadow_map-v.sdr
+++ b/code/def_files/data/effects/shadow_map-v.sdr
@@ -1,9 +1,16 @@
 //? #version 150
+#ifdef GL_ES
+#extension GL_EXT_gpu_shader5: enable
+#extension GL_EXT_clip_cull_distance: enable
+precision highp float;
+precision highp int;
+precision highp samplerBuffer;
+#else
 #extension GL_ARB_gpu_shader5: enable
-
 #ifndef GEOMETRY_FALLBACK
 #extension GL_ARB_shader_viewport_layer_array : enable
 #endif
+#endif
 
 #ifdef VULKAN
 layout(location = 0) in vec4 vertPosition;
@@ -66,12 +73,25 @@ uniform samplerBuffer transform_tex;
 // supports writing gl_Layer from the vertex shader, see CAPABILITY_FAST_SHADOWS).
 #ifdef GEOMETRY_FALLBACK
 out VertexOutput {
-#if !defined(GL_ARB_gpu_shader5)
+#if !defined(GL_ARB_gpu_shader5) && !defined(GL_EXT_gpu_shader5)
 	float instance;
 #endif
 	float clipModel;
 	vec3 normal;
+#ifdef SDR_FLAG_SW_CLIP_FALLBACK
+    float vClipDist;
+#endif
 } vertOut;
+#elif defined(SDR_FLAG_SW_CLIP_FALLBACK)
+#ifdef VULKAN
+layout(location = 0) out VertexOutput {
+	float vClipDist;
+} vertOut;
+#else
+out VertexOutput {
+	float vClipDist;
+} vertOut;
+#endif
 #endif
 
 #define TEXELS_PER_MATRIX 4
@@ -112,7 +132,7 @@ void main()
 #ifdef VULKAN
 	int instanceIndex = gl_InstanceIndex;
 #else
-	#if !defined(GL_ARB_gpu_shader5)
+	#if !defined(GL_ARB_gpu_shader5) && !defined(GL_EXT_gpu_shader5)
 		#ifdef APPLE
 			vertOut.instance = float(gl_InstanceIDARB);
 		#else
@@ -133,11 +153,19 @@ void main()
         gl_Position = position;
     }
 
+#ifndef SDR_FLAG_SW_CLIP_FALLBACK
 	if (use_clip_plane != 0) {
 		gl_ClipDistance[0] = dot(clip_equation, modelMatrix * orient * vertex);
 	} else {
 		gl_ClipDistance[0] = 1.0;
 	}
+#else
+	if (use_clip_plane != 0) {
+		vertOut.vClipDist = dot(clip_equation, modelMatrix * orient * vertex);
+	} else {
+		vertOut.vClipDist = 1.0;
+	}
+#endif
 
 #ifdef GEOMETRY_FALLBACK
     vertOut.normal = normal;
diff --git a/code/def_files/data/effects/shield-impact-f.sdr b/code/def_files/data/effects/shield-impact-f.sdr
index e847867a9b..fbdc1ecd14 100644
--- a/code/def_files/data/effects/shield-impact-f.sdr
+++ b/code/def_files/data/effects/shield-impact-f.sdr
@@ -1,21 +1,22 @@
+#ifdef GL_ES
+precision highp float;
+precision highp int;
+precision highp sampler2DArray;
+#endif
 
 #include "gamma.sdr"
 
 const float EMISSIVE_GAIN = 2.0;
 
+layout(location = 0) out vec4 fragOut0;
+
 #ifdef VULKAN
 layout(location = 0) in vec4 fragImpactUV;
 layout(location = 1) in float fragNormOffset;
-
-layout(location = 0) out vec4 fragOut0;
-
 layout(set = 1, binding = 1) uniform sampler2DArray shieldMap;
 #else
 in vec4 fragImpactUV;
 in float fragNormOffset;
-
-out vec4 fragOut0;
-
 uniform sampler2DArray shieldMap;
 #endif
 
diff --git a/code/def_files/data/effects/shield-impact-v.sdr b/code/def_files/data/effects/shield-impact-v.sdr
index 22f423cb3f..ee078d041a 100644
--- a/code/def_files/data/effects/shield-impact-v.sdr
+++ b/code/def_files/data/effects/shield-impact-v.sdr
@@ -1,3 +1,7 @@
+#ifdef GL_ES
+precision highp float;
+precision highp int;
+#endif
 
 #ifdef VULKAN
 layout(location = 0) in vec4 vertPosition;
diff --git a/code/def_files/data/effects/smaa-blend-f.sdr b/code/def_files/data/effects/smaa-blend-f.sdr
index 055d4b617b..cbb8f3a591 100644
--- a/code/def_files/data/effects/smaa-blend-f.sdr
+++ b/code/def_files/data/effects/smaa-blend-f.sdr
@@ -1,3 +1,7 @@
+#ifdef GL_ES
+precision highp float;
+precision highp sampler2D;
+#endif
 
 #ifdef VULKAN
 layout(std140, set = 2, binding = 0) uniform genericData {
@@ -16,13 +20,13 @@ layout (std140) uniform genericData {
 
 #include "SMAA.sdr"
 
+layout(location=0) out vec4 fragOut0;
+
 #ifdef VULKAN
 layout(location = 0) in vec2 fragTexCoord;
 layout(location = 1) in vec2 fragPixcoord;
 layout(location = 2) in vec4 fragOffset[3];
 
-layout(location = 0) out vec4 fragOut0;
-
 // [0]=edgesTex, [1]=areaTex, [2]=searchTex
 layout(set = 1, binding = 1) uniform sampler2D smaaTex[3];
 #define edgesTex smaaTex[0]
@@ -33,8 +37,6 @@ in vec2 fragTexCoord;
 in vec2 fragPixcoord;
 in vec4 fragOffset[3];
 
-out vec4 fragOut0;
-
 uniform sampler2D edgesTex;
 uniform sampler2D areaTex;
 uniform sampler2D searchTex;
diff --git a/code/def_files/data/effects/smaa-edge-f.sdr b/code/def_files/data/effects/smaa-edge-f.sdr
index 3628177a08..24e27ee0dc 100644
--- a/code/def_files/data/effects/smaa-edge-f.sdr
+++ b/code/def_files/data/effects/smaa-edge-f.sdr
@@ -1,3 +1,7 @@
+#ifdef GL_ES
+precision highp float;
+precision highp sampler2D;
+#endif
 
 #ifdef VULKAN
 layout(std140, set = 2, binding = 0) uniform genericData {
@@ -16,19 +20,17 @@ layout (std140) uniform genericData {
 
 #include "SMAA.sdr"
 
+layout(location = 0) out vec4 fragOut0;
+
 #ifdef VULKAN
 layout(location = 0) in vec2 fragTexCoord;
 layout(location = 1) in vec4 fragOffset[3];
 
-layout(location = 0) out vec4 fragOut0;
-
 layout(set = 1, binding = 1) uniform sampler2D colorTex;
 #else
 in vec2 fragTexCoord;
 in vec4 fragOffset[3];
 
-out vec4 fragOut0;
-
 uniform sampler2D colorTex;
 #endif
 
diff --git a/code/def_files/data/effects/smaa-neighbour-f.sdr b/code/def_files/data/effects/smaa-neighbour-f.sdr
index 56813d9ca5..18973d57d4 100644
--- a/code/def_files/data/effects/smaa-neighbour-f.sdr
+++ b/code/def_files/data/effects/smaa-neighbour-f.sdr
@@ -1,3 +1,7 @@
+#ifdef GL_ES
+precision highp float;
+precision highp sampler2D;
+#endif
 
 #ifdef VULKAN
 layout(std140, set = 2, binding = 0) uniform genericData {
@@ -16,11 +20,12 @@ layout (std140) uniform genericData {
 
 #include "SMAA.sdr"
 
+layout(location = 0) out vec4 fragOut0;
+
 #ifdef VULKAN
 layout(location = 0) in vec2 fragTexCoord;
 layout(location = 1) in vec4 fragOffset;
 
-layout(location = 0) out vec4 fragOut0;
 
 // [0]=colorTex, [1]=blendTex
 layout(set = 1, binding = 1) uniform sampler2D smaaTex[2];
@@ -30,8 +35,6 @@ layout(set = 1, binding = 1) uniform sampler2D smaaTex[2];
 in vec2 fragTexCoord;
 in vec4 fragOffset;
 
-out vec4 fragOut0;
-
 uniform sampler2D colorTex;
 uniform sampler2D blendTex;
 #endif
diff --git a/code/def_files/data/effects/smaa-resolve-f.sdr b/code/def_files/data/effects/smaa-resolve-f.sdr
index fffe936741..4151d19ea4 100644
--- a/code/def_files/data/effects/smaa-resolve-f.sdr
+++ b/code/def_files/data/effects/smaa-resolve-f.sdr
@@ -1,10 +1,15 @@
+#ifdef GL_ES
+precision highp float;
+precision highp sampler2D;
+#endif
+
+layout(location = 0) out vec4 fragOut0;
+
 #ifdef VULKAN
 layout(location = 0) in vec2 fragTexCoord;
-layout(location = 0) out vec4 fragOut0;
 layout(set = 1, binding = 1) uniform sampler2D tex;
 #else
 in vec4 fragTexCoord;
-out vec4 fragOut0;
 uniform sampler2D tex;
 #endif
 
diff --git a/code/def_files/data/effects/tonemapping-f.sdr b/code/def_files/data/effects/tonemapping-f.sdr
index 98d7a04838..93d12a134c 100644
--- a/code/def_files/data/effects/tonemapping-f.sdr
+++ b/code/def_files/data/effects/tonemapping-f.sdr
@@ -1,13 +1,18 @@
+#ifdef GL_ES
+precision highp float;
+precision highp int;
+precision highp sampler2D;
+#endif
 
 #include "gamma.sdr"
 
+layout(location=0) out vec4 fragOut0;
+
 #ifdef VULKAN
 layout(location = 0) in vec2 fragTexCoord;
-layout(location = 0) out vec4 fragOut0;
 layout(set = 1, binding = 1) uniform sampler2D tex;
 #else
 in vec4 fragTexCoord;
-out vec4 fragOut0;
 uniform sampler2D tex;
 #endif
 
diff --git a/code/def_files/data/effects/video-f.sdr b/code/def_files/data/effects/video-f.sdr
index 8ea4044baa..0322b26813 100644
--- a/code/def_files/data/effects/video-f.sdr
+++ b/code/def_files/data/effects/video-f.sdr
@@ -1,6 +1,12 @@
+#ifdef GL_ES
+precision highp float;
+precision highp sampler2DArray;
+#endif
+
+layout(location = 0) out vec4 fragOut0;
+
 #ifdef VULKAN
 layout(location = 0) in vec4 fragTexCoord;
-layout(location = 0) out vec4 fragOut0;
 
 layout(set = 1, binding = 1) uniform sampler2DArray textures[16];
 #define ytex textures[0]
@@ -8,7 +14,6 @@ layout(set = 1, binding = 1) uniform sampler2DArray textures[16];
 #define vtex textures[2]
 #else
 in vec4 fragTexCoord;
-out vec4 fragOut0;
 uniform sampler2DArray ytex;
 uniform sampler2DArray utex;
 uniform sampler2DArray vtex;
diff --git a/code/def_files/data/effects/volumetric-f.sdr b/code/def_files/data/effects/volumetric-f.sdr
index b00e721317..6fe0c0e5e5 100644
--- a/code/def_files/data/effects/volumetric-f.sdr
+++ b/code/def_files/data/effects/volumetric-f.sdr
@@ -1,7 +1,14 @@
+#ifdef GL_ES
+precision highp float;
+precision highp int;
+precision highp sampler2D;
+precision highp sampler3D;
+#endif
+
+layout(location = 0) out vec4 fragOut0;
 
 #ifdef VULKAN
 layout(location = 0) in vec2 fragTexCoord;
-layout(location = 0) out vec4 fragOut0;
 layout(set = 1, binding = 1) uniform sampler2D tex2D[16];
 #define composite tex2D[0]
 #define emissive tex2D[1]
@@ -10,7 +17,7 @@ layout(set = 1, binding = 5) uniform sampler3D volume_tex;
 layout(set = 1, binding = 6) uniform sampler3D noise_volume_tex;
 #else
 in vec4 fragTexCoord;
-out vec4 fragOut0;
+
 layout (binding = 0) uniform sampler2D composite;
 layout (binding = 1) uniform sampler2D emissive;
 layout (binding = 2) uniform sampler2D depth_tex;
@@ -77,7 +84,7 @@ void main()
 #else
 	vec4 eyeDirection = p_inv * vec4(fragTexCoord.xy * 2.0 - 1.0, -1, 1);
 #endif
-    eyeDirection.w = 0;
+    eyeDirection.w = 0.0;
     vec3 rayDirection = normalize((v_inv * eyeDirection).xyz);
 
 	vec4 color_in = texture(composite, fragTexCoord.xy);
@@ -103,14 +110,14 @@ void main()
 #endif
 
 	//The t at which the ray enters the nebula cube
-	float maxtMin = max(0,max(tMin.x, max(tMin.y, tMin.z)));
+	float maxtMin = max(0.0, max(tMin.x, max(tMin.y, tMin.z)));
 	//The t at which the ray leaves the nebula cube
 	float mintMax = min(fragDepth, min(tMax.x, min(tMax.y, tMax.z)));
 
 	//The cumulative one minus alpha value of the nebula. Corresponds to the multiplier of the current step when additively drawing to a fragment for which the steps closer to the camera are already drawn.
-	float cumOMAlpha = 1;
+	float cumOMAlpha = 1.0;
 	//The cumulative distance already travelled through the nebula.
-	float cumnebdist = 0;
+	float cumnebdist = 0.0;
 	//The color of the current fragment
 	vec3 cumcolor = vec3(0, 0, 0);
 
@@ -121,6 +128,14 @@ void main()
 
 	vec3 sidestep = 1.0 / vec3(textureSize(volume_tex, 0));
 
+#ifdef GL_ES
+	// The emissive texture has a complete mip chain generated by the engine.
+	ivec2 emissiveSize = textureSize(emissive, 0);
+	float maxEmissiveLod = float(findMSB(max(emissiveSize.x, emissiveSize.y)));
+#else
+	float maxEmissiveLod = float(textureQueryLevels(emissive) - 1);
+#endif
+
 	for(float stept = maxtMin; stept < mintMax;) {
 		//Step setup
 		vec3 position = camera + rayDirection * stept - nebPos;
@@ -159,7 +174,7 @@ void main()
 #ifdef NOISE
 			//Mix the actual nebula color with the noise color depending on the product of the noise channels multiplied with intensity, smooth-clamped from 0 to 1
 			vec3 stepcolor_neb = mix(nebulaColor, noiseColor,
-				smoothstep(0, 1, (textureGrad(noise_volume_tex, position / noiseColorScale1, gradX, gradY).r + textureGrad(noise_volume_tex, position / noiseColorScale2, gradX, gradY).g) / 2.0 * noiseIntensity));
+				smoothstep(0.0, 1.0, (textureGrad(noise_volume_tex, position / noiseColorScale1, gradX, gradY).r + textureGrad(noise_volume_tex, position / noiseColorScale2, gradX, gradY).g) / 2.0 * noiseIntensity));
 #else
 			vec3 stepcolor_neb = nebulaColor;
 #endif
@@ -169,19 +184,19 @@ void main()
 			//From the current position in the volumetric cloud, sample towards the sun to test whether or not the current part of the nebula is bright or not
 			for(int dlstep = 1; dlstep <= directionalLightSampleSteps; dlstep++){
 				//TODO Sample these in a cone towards the sun, not just a line. Also add the high-distance sample for concave nebulae
-				vec3 dlsteppos = (position - globalLightDirection * (dlstep * directionalLightStepSize)) / nebSize + 0.5;
-				float dlstepalpha = textureGrad(volume_tex, dlsteppos, gradX, gradY).a * step(0, dlsteppos.x) * step(dlsteppos.x, 1) * step(0, dlsteppos.y) * step(dlsteppos.y, 1) * step(0, dlsteppos.z) * step(dlsteppos.z, 1);
+				vec3 dlsteppos = (position - globalLightDirection * (float(dlstep) * directionalLightStepSize)) / nebSize + 0.5;
+				float dlstepalpha = textureGrad(volume_tex, dlsteppos, gradX, gradY).a * step(0.0, dlsteppos.x) * step(dlsteppos.x, 1.0) * step(0.0, dlsteppos.y) * step(dlsteppos.y, 1.0) * step(0.0, dlsteppos.z) * step(dlsteppos.z, 1.0);
 				directionalLightDepth += dlstepalpha * directionalLightStep;
 			}
-			stepcolor_diffuse *= beer_powder_norm * (1 - exp(-directionalLightDepth * 2.0)) * exp(-directionalLightDepth);
+			stepcolor_diffuse *= beer_powder_norm * (1.0 - exp(-directionalLightDepth * 2.0)) * exp(-directionalLightDepth);
 
 			//Emissive
 			cumnebdist += stepcolor_alpha * stepsize_current;
-			vec3 emissive_lod = textureLod(emissive, fragTexCoord.xy, clamp(cumnebdist * emissiveSpreadFactor, 0, float(textureQueryLevels(emissive) - 1))).rgb;
-			vec3 stepcolor_emissive = clamp(emissive_lod.rgb * pow(alphalim, 1.0 / (opacitydistance / ((fragDepth - stept) * emissiveFalloff + 0.01))) * emissiveIntensity, 0, 1);
+			vec3 emissive_lod = textureLod(emissive, fragTexCoord.xy, clamp(cumnebdist * emissiveSpreadFactor, 0.0, maxEmissiveLod)).rgb;
+			vec3 stepcolor_emissive = clamp(emissive_lod.rgb * pow(alphalim, 1.0 / (opacitydistance / ((fragDepth - stept) * emissiveFalloff + 0.01))) * emissiveIntensity, 0.0, 1.0);
 
 			//Step finish
-			vec3 stepcolor = clamp(stepcolor_diffuse + stepcolor_emissive, 0, 1);
+			vec3 stepcolor = clamp(stepcolor_diffuse + stepcolor_emissive, 0.0, 1.0);
 			cumcolor += stepalpha * cumOMAlpha * stepcolor;
 		}
 
diff --git a/code/graphics/opengl/es_compatibility.h b/code/graphics/opengl/es_compatibility.h
index a864be1545..5ccece3378 100644
--- a/code/graphics/opengl/es_compatibility.h
+++ b/code/graphics/opengl/es_compatibility.h
@@ -32,6 +32,7 @@
 #define GL_CLAMP_VERTEX_COLOR					0x891A
 #define GL_CLAMP_FRAGMENT_COLOR					0x891B
 #define GL_FIXED_ONLY							0x891D
+#define GLAD_GL_ARB_shader_viewport_layer_array 0 // Disabled, no gl_layer in vertex shader //0x8DAE
 
 //Enums Redefinitions
 #define GL_CLIP_DISTANCE0						GL_CLIP_DISTANCE0_EXT // GL_EXT_clip_cull_distance
@@ -48,6 +49,7 @@
 #define GLAD_GL_ARB_texture_storage				GL_TRUE // ES 3.2
 #define GLAD_GL_ARB_draw_buffers_blend			GL_TRUE // ES 3.2 (glBlendFunci and glBlendEquationi)
 #define GLAD_GL_ARB_vertex_attrib_binding		GL_TRUE // ES 3.1
+#define GL_DEPTH_CLAMP							GL_DEPTH_CLAMP_EXT
 
 //Functions Redefinitions
 #define glBlendFunciARB					glBlendFunci // ES 3.2
@@ -234,9 +236,7 @@ inline void glDrawBuffer(GLenum buf)
 	}
 }
 
-// does not exist on ES, ES uses layout(location=) directly on shader
-// Notes: 
-// -This function is not required to run.
+// ES uses layout(location = ) directly on shader
 #define glBindFragDataLocation(program, colorNumber, name) ((void)0)
 
 // glPolygonMode() is not supported on ES,  no wireframe, GL_FILL is default, GL_POINTS, and GL_LINES needs an alternative path
@@ -254,6 +254,7 @@ static inline void glQueryCounter(GLuint id, GLenum target)
 	#else
 		(void)id;
 	#endif
+		(void)target;
 }
 
 // glGetCompressedTexImage not present on GLES and no equivalent
diff --git a/code/graphics/opengl/gropengl.cpp b/code/graphics/opengl/gropengl.cpp
index 73f1e100c8..509406d4cd 100644
--- a/code/graphics/opengl/gropengl.cpp
+++ b/code/graphics/opengl/gropengl.cpp
@@ -1453,7 +1453,9 @@ bool gr_opengl_init(std::unique_ptr<os::GraphicsOperations>&& graphicsOps)
 			"Deferred lightning is enabled in settings but the gpu does not support the minimum of 6 draw buffers. "
 			"This will result in rendering errors.");
 	}
-
+	
+	mprintf(("  Depth Clamp support : %s\n", GLAD_GL_EXT_depth_clamp ? NOX("YES") : NOX("NO")));
+	mprintf(("  HW Cull distance support : %s\n", GLAD_GL_EXT_clip_cull_distance ? NOX("YES") : NOX("NO")));
 	mprintf(("  Precompiled shaders support : %s\n", GLAD_GL_OES_get_program_binary ? NOX("YES") : NOX("NO")));
 	mprintf(("  Immutable buffer storage support : %s\n", GLAD_GL_EXT_buffer_storage ? NOX("YES") : NOX("NO")));
 	mprintf(("  BGRA8888 format support: %s\n", GLAD_GL_EXT_texture_format_BGRA8888 ? NOX("YES") : NOX("NO")));
diff --git a/code/graphics/opengl/gropenglshader.cpp b/code/graphics/opengl/gropenglshader.cpp
index 41c3142d15..335bbceb42 100644
--- a/code/graphics/opengl/gropenglshader.cpp
+++ b/code/graphics/opengl/gropenglshader.cpp
@@ -178,10 +178,20 @@ static SCP_string opengl_shader_get_header(shader_type type_id, int flags, bool
 
 #ifndef USE_OPENGL_ES
 	sflags << "#version " << GLSL_version << " core\n";
+	if (GLSL_version < 330) {
+		sflags << "#extension GL_ARB_explicit_attrib_location : enable\n";
+	}
 #else
 	sflags << "#version " << GLSL_version << " es\n";
 #endif
 	sflags << "#define OPENGL\n";
+
+#ifdef USE_OPENGL_ES
+	if (!GLAD_GL_EXT_clip_cull_distance) {
+		sflags << "#define SDR_FLAG_SW_CLIP_FALLBACK\n";
+	}
+#endif
+
 	sflags << shader_get_shadow_cascade_defines();
 	sflags << shader_get_rt_shadow_light_limit_define();
 
diff --git a/code/graphics/opengl/gropenglstate.cpp b/code/graphics/opengl/gropenglstate.cpp
index 824bc09b36..060eb6dd42 100644
--- a/code/graphics/opengl/gropenglstate.cpp
+++ b/code/graphics/opengl/gropenglstate.cpp
@@ -360,6 +360,13 @@ GLboolean opengl_state::ClipDistance(GLint num, bool state)
 
 	GLboolean save_state = clipdistance_Status[num];
 
+#ifdef USE_OPENGL_ES
+	if (!GLAD_GL_EXT_clip_cull_distance) {
+		clipdistance_Status[num] = state;
+		return save_state;
+	}
+#endif
+
 	if (state != clipdistance_Status[num]) {
 		if (state) {
 			glEnable(GL_CLIP_DISTANCE0+num);
diff --git a/code/graphics/opengl/gropengltnl.cpp b/code/graphics/opengl/gropengltnl.cpp
index 7061314fb8..d2f64076d9 100644
--- a/code/graphics/opengl/gropengltnl.cpp
+++ b/code/graphics/opengl/gropengltnl.cpp
@@ -732,7 +732,13 @@ void gr_opengl_shadow_map_start(matrix4 *shadow_view_matrix, const matrix *light
 
 		glClear(GL_DEPTH_BUFFER_BIT);
 
+#ifdef USE_OPENGL_ES
+		if (GLAD_GL_EXT_depth_clamp) {
+			glEnable(GL_DEPTH_CLAMP);
+		}
+#else
 		glEnable(GL_DEPTH_CLAMP);
+#endif
 
 		Glowpoint_override_save = Glowpoint_override;
 		Glowpoint_override = true;
@@ -753,7 +759,13 @@ void gr_opengl_shadow_map_end()
 {
 	gr_end_view_matrix();
 
+#ifdef USE_OPENGL_ES
+	if (GLAD_GL_EXT_depth_clamp) {
+		glDisable(GL_DEPTH_CLAMP);
+	}
+#else
 	glDisable(GL_DEPTH_CLAMP);
+#endif
 
 	gr_zbuffer_set(ZBUFFER_TYPE_FULL);
 	GL_state.PopFramebufferState();
@@ -1136,6 +1148,12 @@ void opengl_tnl_set_material_nanovg(nanovg_material* material_info) {
 void opengl_tnl_set_material_decal(decal_material* material_info) {
 	opengl_tnl_set_material(material_info, false);
 
+#ifdef USE_OPENGL_ES
+	// ES decal outputs use G-buffer locations instead of packed draw-buffer indices.
+	GL_state.SetAlphaBlendModei(2, material_info->get_blend_mode(1));
+	GL_state.SetAlphaBlendModei(4, material_info->get_blend_mode(2));
+#endif
+
 	float u_scale, v_scale;
 	uint32_t array_index;
 
diff --git a/code/graphics/vulkan/VulkanRendererSetup.cpp b/code/graphics/vulkan/VulkanRendererSetup.cpp
index bcb5b57d6c..9ce690fa02 100644
--- a/code/graphics/vulkan/VulkanRendererSetup.cpp
+++ b/code/graphics/vulkan/VulkanRendererSetup.cpp
@@ -459,8 +459,11 @@ bool VulkanRenderer::initialize()
 	setTextureManager(m_textureManager.get());
 
 	// Initialize shader manager
+	if (m_deviceFeatures.shaderClipDistance != VK_TRUE) {
+		mprintf(("Vulkan: HW clip distance not supported, using software clip distance fallback\n"));
+	}
 	m_shaderManager = std::make_unique<VulkanShaderManager>();
-	if (!m_shaderManager->init(m_device.get())) {
+	if (!m_shaderManager->init(m_device.get(), m_deviceFeatures.shaderClipDistance == VK_TRUE)) {
 		nprintf(("vulkan", "Failed to initialize Vulkan shader manager!\n"));
 		return false;
 	}
diff --git a/code/graphics/vulkan/VulkanShader.cpp b/code/graphics/vulkan/VulkanShader.cpp
index da9a29bc5d..d1e7763fb0 100644
--- a/code/graphics/vulkan/VulkanShader.cpp
+++ b/code/graphics/vulkan/VulkanShader.cpp
@@ -34,7 +34,7 @@ void vulkan_recompile_all_shaders(const std::function<void(size_t, size_t)>& pro
 VulkanShaderManager::VulkanShaderManager() = default;
 VulkanShaderManager::~VulkanShaderManager() = default;
 
-bool VulkanShaderManager::init(vk::Device device)
+bool VulkanShaderManager::init(vk::Device device, bool hwClipDistance)
 {
 	if (m_initialized) {
 		return true;
@@ -44,7 +44,7 @@ bool VulkanShaderManager::init(vk::Device device)
 
 	// Initialize runtime shader compiler
 	m_compiler = std::make_unique<VulkanShaderCompiler>();
-	if (!m_compiler->init()) {
+	if (!m_compiler->init(hwClipDistance)) {
 		nprintf(("vulkan", "VulkanShaderManager: Failed to initialize shader compiler!\n"));
 		return false;
 	}
diff --git a/code/graphics/vulkan/VulkanShader.h b/code/graphics/vulkan/VulkanShader.h
index 0f3e13381c..25a1c724ee 100644
--- a/code/graphics/vulkan/VulkanShader.h
+++ b/code/graphics/vulkan/VulkanShader.h
@@ -59,7 +59,7 @@ public:
 	 * @param device Vulkan logical device
 	 * @return true on success
 	 */
-	bool init(vk::Device device);
+	bool init(vk::Device device, bool hwClipDistance);
 
 	/**
 	 * @brief Shutdown and release all shader modules
diff --git a/code/graphics/vulkan/VulkanShaderCompiler.cpp b/code/graphics/vulkan/VulkanShaderCompiler.cpp
index 2ff077b19e..5be2672e50 100644
--- a/code/graphics/vulkan/VulkanShaderCompiler.cpp
+++ b/code/graphics/vulkan/VulkanShaderCompiler.cpp
@@ -102,8 +102,9 @@ VulkanShadercLibrary::VulkanShadercLibrary()
 VulkanShaderCompiler::VulkanShaderCompiler() = default;
 VulkanShaderCompiler::~VulkanShaderCompiler() = default;
 
-bool VulkanShaderCompiler::init()
+bool VulkanShaderCompiler::init(bool hwClipDistance)
 {
+	m_hwClipDistance = hwClipDistance;
 	if (m_initialized) {
 		return true;
 	}
@@ -148,6 +149,13 @@ SCP_string VulkanShaderCompiler::buildHeader(vk::ShaderStageFlagBits /*stage*/,
 	// shaderc automatically predefines VULKAN=100 when targeting Vulkan,
 	// so we do NOT define it here — doing so causes a "Macro redefined" error.
 
+	// gl_ClipDistance[] requires the shaderClipDistance device feature. When the
+	// device supports it, use the hardware clip path, otherwise
+	// the shaders fall back to the vClipDist varying (software clipping).
+	if (!m_hwClipDistance) {
+		header += "#define SDR_FLAG_SW_CLIP_FALLBACK\n";
+	}
+
 	// Blinn-Phong lighting model (matches OpenGL's opengl_shader_get_header)
 	if (Detail.lighting < 3) {
 		header += "#define FLAG_LIGHT_MODEL_BLINN_PHONG\n";
diff --git a/code/graphics/vulkan/VulkanShaderCompiler.h b/code/graphics/vulkan/VulkanShaderCompiler.h
index 73837ef7b6..a4913e2371 100644
--- a/code/graphics/vulkan/VulkanShaderCompiler.h
+++ b/code/graphics/vulkan/VulkanShaderCompiler.h
@@ -23,7 +23,7 @@ public:
 	VulkanShaderCompiler();
 	~VulkanShaderCompiler();
 
-	bool init();
+	bool init(bool hwClipDistance);
 	void shutdown();
 
 	/**
@@ -69,6 +69,7 @@ private:
 
 	std::unique_ptr<VulkanShadercLibrary> m_shaderc;
 	bool m_initialized = false;
+	bool m_hwClipDistance = false;
 };
 
 } // namespace graphics::vulkan
diff --git a/freespace2/SDLGraphicsOperations.cpp b/freespace2/SDLGraphicsOperations.cpp
index 32702c0fa3..4c5a45c2b7 100644
--- a/freespace2/SDLGraphicsOperations.cpp
+++ b/freespace2/SDLGraphicsOperations.cpp
@@ -328,8 +328,9 @@ std::unique_ptr<os::OpenGLContext> SDLGraphicsOperations::createOpenGLContext(os
 
 	Assertion(ImGui::GetCurrentContext() != nullptr, "Can't use ImGui without a valid context!");
 
-	#ifndef USE_OPENGL_ES
 	ImGui_ImplSDL3_InitForOpenGL(viewport->toSDLWindow(), ctx);
+
+	#ifndef USE_OPENGL_ES
 	ImGui_ImplOpenGL3_Init();
 	#else
 	ImGui_ImplOpenGL3_Init("#version 300 es");
diff --git a/lib/opengl/gl/glad_es/include/glad/glad.h b/lib/opengl/gl/glad_es/include/glad/glad.h
index 550c4ad13b..5f5cdf5d54 100644
--- a/lib/opengl/gl/glad_es/include/glad/glad.h
+++ b/lib/opengl/gl/glad_es/include/glad/glad.h
@@ -1,6 +1,6 @@
 /*
 
-    OpenGL ES loader generated by glad 0.1.36 on Wed Aug 27 15:16:54 2025.
+    OpenGL ES loader generated by glad 0.1.36 on Sat Jul  4 19:49:32 2026.
 
     Language/Generator: C/C++
     Specification: gl
@@ -10,6 +10,7 @@
         GL_EXT_buffer_storage,
         GL_EXT_clip_cull_distance,
         GL_EXT_color_buffer_float,
+        GL_EXT_depth_clamp,
         GL_EXT_disjoint_timer_query,
         GL_EXT_gpu_shader5,
         GL_EXT_multisampled_render_to_texture,
@@ -27,9 +28,9 @@
     Reproducible: False
 
     Commandline:
-        --profile="core" --api="gles2=3.2" --generator="c" --spec="gl" --extensions="GL_EXT_buffer_storage,GL_EXT_clip_cull_distance,GL_EXT_color_buffer_float,GL_EXT_disjoint_timer_query,GL_EXT_gpu_shader5,GL_EXT_multisampled_render_to_texture,GL_EXT_multisampled_render_to_texture2,GL_EXT_texture_compression_bptc,GL_EXT_texture_compression_s3tc,GL_EXT_texture_filter_anisotropic,GL_EXT_texture_format_BGRA8888,GL_KHR_debug,GL_KHR_texture_compression_astc_ldr,GL_OES_get_program_binary"
+        --profile="core" --api="gles2=3.2" --generator="c" --spec="gl" --extensions="GL_EXT_buffer_storage,GL_EXT_clip_cull_distance,GL_EXT_color_buffer_float,GL_EXT_depth_clamp,GL_EXT_disjoint_timer_query,GL_EXT_gpu_shader5,GL_EXT_multisampled_render_to_texture,GL_EXT_multisampled_render_to_texture2,GL_EXT_texture_compression_bptc,GL_EXT_texture_compression_s3tc,GL_EXT_texture_filter_anisotropic,GL_EXT_texture_format_BGRA8888,GL_KHR_debug,GL_KHR_texture_compression_astc_ldr,GL_OES_get_program_binary"
     Online:
-        https://glad.dav1d.de/#profile=core&language=c&specification=gl&loader=on&api=gles2%3D3.2&extensions=GL_EXT_buffer_storage&extensions=GL_EXT_clip_cull_distance&extensions=GL_EXT_color_buffer_float&extensions=GL_EXT_disjoint_timer_query&extensions=GL_EXT_gpu_shader5&extensions=GL_EXT_multisampled_render_to_texture&extensions=GL_EXT_multisampled_render_to_texture2&extensions=GL_EXT_texture_compression_bptc&extensions=GL_EXT_texture_compression_s3tc&extensions=GL_EXT_texture_filter_anisotropic&extensions=GL_EXT_texture_format_BGRA8888&extensions=GL_KHR_debug&extensions=GL_KHR_texture_compression_astc_ldr&extensions=GL_OES_get_program_binary
+        https://glad.dav1d.de/#profile=core&language=c&specification=gl&loader=on&api=gles2%3D3.2&extensions=GL_EXT_buffer_storage&extensions=GL_EXT_clip_cull_distance&extensions=GL_EXT_color_buffer_float&extensions=GL_EXT_depth_clamp&extensions=GL_EXT_disjoint_timer_query&extensions=GL_EXT_gpu_shader5&extensions=GL_EXT_multisampled_render_to_texture&extensions=GL_EXT_multisampled_render_to_texture2&extensions=GL_EXT_texture_compression_bptc&extensions=GL_EXT_texture_compression_s3tc&extensions=GL_EXT_texture_filter_anisotropic&extensions=GL_EXT_texture_format_BGRA8888&extensions=GL_KHR_debug&extensions=GL_KHR_texture_compression_astc_ldr&extensions=GL_OES_get_program_binary
 */
 
 
@@ -2257,6 +2258,7 @@ GLAPI PFNGLTEXSTORAGE3DMULTISAMPLEPROC glad_glTexStorage3DMultisample;
 #define GL_CLIP_DISTANCE5_EXT 0x3005
 #define GL_CLIP_DISTANCE6_EXT 0x3006
 #define GL_CLIP_DISTANCE7_EXT 0x3007
+#define GL_DEPTH_CLAMP_EXT 0x864F
 #define GL_QUERY_COUNTER_BITS_EXT 0x8864
 #define GL_CURRENT_QUERY_EXT 0x8865
 #define GL_QUERY_RESULT_EXT 0x8866
@@ -2366,6 +2368,10 @@ GLAPI int GLAD_GL_EXT_clip_cull_distance;
 #define GL_EXT_color_buffer_float 1
 GLAPI int GLAD_GL_EXT_color_buffer_float;
 #endif
+#ifndef GL_EXT_depth_clamp
+#define GL_EXT_depth_clamp 1
+GLAPI int GLAD_GL_EXT_depth_clamp;
+#endif
 #ifndef GL_EXT_disjoint_timer_query
 #define GL_EXT_disjoint_timer_query 1
 GLAPI int GLAD_GL_EXT_disjoint_timer_query;
diff --git a/lib/opengl/gl/glad_es/src/glad.c b/lib/opengl/gl/glad_es/src/glad.c
index e7bae0f786..df24c8490e 100644
--- a/lib/opengl/gl/glad_es/src/glad.c
+++ b/lib/opengl/gl/glad_es/src/glad.c
@@ -1,6 +1,6 @@
 /*
 
-    OpenGL ES loader generated by glad 0.1.36 on Wed Aug 27 15:16:54 2025.
+    OpenGL ES loader generated by glad 0.1.36 on Sat Jul  4 19:49:32 2026.
 
     Language/Generator: C/C++
     Specification: gl
@@ -10,6 +10,7 @@
         GL_EXT_buffer_storage,
         GL_EXT_clip_cull_distance,
         GL_EXT_color_buffer_float,
+        GL_EXT_depth_clamp,
         GL_EXT_disjoint_timer_query,
         GL_EXT_gpu_shader5,
         GL_EXT_multisampled_render_to_texture,
@@ -27,9 +28,9 @@
     Reproducible: False
 
     Commandline:
-        --profile="core" --api="gles2=3.2" --generator="c" --spec="gl" --extensions="GL_EXT_buffer_storage,GL_EXT_clip_cull_distance,GL_EXT_color_buffer_float,GL_EXT_disjoint_timer_query,GL_EXT_gpu_shader5,GL_EXT_multisampled_render_to_texture,GL_EXT_multisampled_render_to_texture2,GL_EXT_texture_compression_bptc,GL_EXT_texture_compression_s3tc,GL_EXT_texture_filter_anisotropic,GL_EXT_texture_format_BGRA8888,GL_KHR_debug,GL_KHR_texture_compression_astc_ldr,GL_OES_get_program_binary"
+        --profile="core" --api="gles2=3.2" --generator="c" --spec="gl" --extensions="GL_EXT_buffer_storage,GL_EXT_clip_cull_distance,GL_EXT_color_buffer_float,GL_EXT_depth_clamp,GL_EXT_disjoint_timer_query,GL_EXT_gpu_shader5,GL_EXT_multisampled_render_to_texture,GL_EXT_multisampled_render_to_texture2,GL_EXT_texture_compression_bptc,GL_EXT_texture_compression_s3tc,GL_EXT_texture_filter_anisotropic,GL_EXT_texture_format_BGRA8888,GL_KHR_debug,GL_KHR_texture_compression_astc_ldr,GL_OES_get_program_binary"
     Online:
-        https://glad.dav1d.de/#profile=core&language=c&specification=gl&loader=on&api=gles2%3D3.2&extensions=GL_EXT_buffer_storage&extensions=GL_EXT_clip_cull_distance&extensions=GL_EXT_color_buffer_float&extensions=GL_EXT_disjoint_timer_query&extensions=GL_EXT_gpu_shader5&extensions=GL_EXT_multisampled_render_to_texture&extensions=GL_EXT_multisampled_render_to_texture2&extensions=GL_EXT_texture_compression_bptc&extensions=GL_EXT_texture_compression_s3tc&extensions=GL_EXT_texture_filter_anisotropic&extensions=GL_EXT_texture_format_BGRA8888&extensions=GL_KHR_debug&extensions=GL_KHR_texture_compression_astc_ldr&extensions=GL_OES_get_program_binary
+        https://glad.dav1d.de/#profile=core&language=c&specification=gl&loader=on&api=gles2%3D3.2&extensions=GL_EXT_buffer_storage&extensions=GL_EXT_clip_cull_distance&extensions=GL_EXT_color_buffer_float&extensions=GL_EXT_depth_clamp&extensions=GL_EXT_disjoint_timer_query&extensions=GL_EXT_gpu_shader5&extensions=GL_EXT_multisampled_render_to_texture&extensions=GL_EXT_multisampled_render_to_texture2&extensions=GL_EXT_texture_compression_bptc&extensions=GL_EXT_texture_compression_s3tc&extensions=GL_EXT_texture_filter_anisotropic&extensions=GL_EXT_texture_format_BGRA8888&extensions=GL_KHR_debug&extensions=GL_KHR_texture_compression_astc_ldr&extensions=GL_OES_get_program_binary
 */
 
 #include <stdio.h>
@@ -501,6 +502,7 @@ PFNGLWAITSYNCPROC glad_glWaitSync = NULL;
 int GLAD_GL_EXT_buffer_storage = 0;
 int GLAD_GL_EXT_clip_cull_distance = 0;
 int GLAD_GL_EXT_color_buffer_float = 0;
+int GLAD_GL_EXT_depth_clamp = 0;
 int GLAD_GL_EXT_disjoint_timer_query = 0;
 int GLAD_GL_EXT_gpu_shader5 = 0;
 int GLAD_GL_EXT_multisampled_render_to_texture = 0;
@@ -969,6 +971,7 @@ static int find_extensionsGLES2(void) {
 	GLAD_GL_EXT_buffer_storage = has_ext("GL_EXT_buffer_storage");
 	GLAD_GL_EXT_clip_cull_distance = has_ext("GL_EXT_clip_cull_distance");
 	GLAD_GL_EXT_color_buffer_float = has_ext("GL_EXT_color_buffer_float");
+	GLAD_GL_EXT_depth_clamp = has_ext("GL_EXT_depth_clamp");
 	GLAD_GL_EXT_disjoint_timer_query = has_ext("GL_EXT_disjoint_timer_query");
 	GLAD_GL_EXT_gpu_shader5 = has_ext("GL_EXT_gpu_shader5");
 	GLAD_GL_EXT_multisampled_render_to_texture = has_ext("GL_EXT_multisampled_render_to_texture");