GLES 3.0 Support on HW Renderer

updated makefiles for:
- android
- ios
- emscripten
- rpi4

tested on emscripten, GLES3 must be explicitly enabled for android and ios

fixed some things in glsm (libretro-common)

colors are not 100% perfect on GLES3 due to it not including the 1555 ABGR color format. GLES3 uses 5551 instead.

Makefile

@@ -1,6 +1,8 @@
 DEBUG = 0
 FRONTEND_SUPPORTS_RGB565 = 1
 HAVE_OPENGL = 0
+GLES = 0
+GLES3 = 0 # HW renderer now supported on GLES3
 HAVE_VULKAN = 0
 HAVE_JIT = 0
 HAVE_CHD = 1
@@ -173,6 +175,8 @@ else ifneq (,$(findstring ios,$(platform)))
    endif
    ifeq ($(HAVE_OPENGL),1)
       GL_LIB := -framework OpenGLES
+      GLES = 1
+      GLES3 = 0
    endif
 
    CC = cc -arch $(iarch) -isysroot $(IOSSDK)
@@ -324,12 +328,18 @@ else ifeq ($(platform), gcw0)
 else ifeq ($(platform), emscripten)
    TARGET  := $(TARGET_NAME)_libretro_$(platform).bc
    fpic    := -fPIC
-   SHARED  := -shared -Wl,--no-undefined -Wl,--version-script=link.T
+   FLAGS   += -DEMSCRIPTEN
-   LDFLAGS += $(PTHREAD_FLAGS)
+   FLAGS   += -msimd128 -ftree-vectorize
-   STATIC_LINKING = 1
+
+   HAVE_OPENGL = 1
+   GLES = 1
+   GLES3 = 1
    HAVE_LIGHTREC = 0
    NEED_THREADING = 0
    HAVE_CDROM = 0
+   THREADED_RECOMPILER = 0
+
+   STATIC_LINKING = 1
 
 # Raspberry Pi 4 in 64bit mode
 else ifeq ($(platform), rpi4_64)
@@ -342,7 +352,7 @@ else ifeq ($(platform), rpi4_64)
    LDFLAGS += $(PTHREAD_FLAGS) -ldl -lrt
    HAVE_LIGHTREC = 1
    FLAGS += -DHAVE_SHM
-   GLES = 1
+   GLES3 = 1
    GL_LIB := -lGLESv2
    HAVE_CDROM = 0
 

Makefile.common

@@ -40,11 +40,15 @@ ZLIB_SOURCES_C = \
 		 $(ZLIB_DIR)/zutil.c
 
 ifeq ($(HAVE_OPENGL), 1)
-   ifeq ($(GLES), 1)
+   ifeq ($(GLES3), 1)
+      GLFLAGS  := -DHAVE_OPENGLES -DHAVE_OPENGLES3
+      CFLAGS   += $(GLFLAGS)
+      CXXFLAGS += $(GLFLAGS)
+      SOURCES_C += $(LIBRETRO_COMM_DIR)/glsym/glsym_es3.c
+   else ifeq ($(GLES), 1)
       GLFLAGS  := -DHAVE_OPENGLES -DHAVE_OPENGLES2
       CFLAGS   += $(GLFLAGS)
       CXXFLAGS += $(GLFLAGS)
-
       SOURCES_C += $(LIBRETRO_COMM_DIR)/glsym/glsym_es2.c
    else
       GLFLAGS   := -DHAVE_OPENGL -DCORE

jni/Android.mk

@@ -2,6 +2,10 @@ LOCAL_PATH := $(call my-dir)
 
 CORE_DIR := $(LOCAL_PATH)/..
 
+# set these
+HAVE_HW = 0
+HAVE_OPENGLES3 = 0
+
 DEBUG                    := 0
 FRONTEND_SUPPORTS_RGB565 := 1
 NEED_CD                  := 1
@@ -10,6 +14,7 @@ NEED_DEINTERLACER        := 1
 NEED_THREADING           := 1
 NEED_TREMOR              := 1
 GLES                     := 0
+GLES3                    := 0
 HAVE_OPENGL              := 0
 HAVE_VULKAN              := 0
 HAVE_CHD                 := 1
@@ -23,9 +28,12 @@ ifeq ($(TARGET_ARCH),x86)
 endif
 
 ifeq ($(HAVE_HW),1)
-  # gles support will not compile
+  ifeq ($(HAVE_OPENGLES3),1)
-  #GLES        := 1
+    HAVE_OPENGL := 1
-  #HAVE_OPENGL := 1
+    GLES        := 1
+    GLES3       := 1
+    GL_LIB := -lGLESv3
+  endif
 
   ifneq ($(TARGET_ARCH_ABI),armeabi)
     HAVE_VULKAN := 1

libretro-common/glsm/glsm.c

@@ -646,18 +646,18 @@ void rglBlendFunc(GLenum sfactor, GLenum dfactor)
  * Core in:
  * OpenGL    : 1.4
  */
-void rglBlendFuncSeparate(GLenum sfactor, GLenum dfactor)
+void rglBlendFuncSeparate(GLenum srcRGB, GLenum dstRGB, GLenum srcAlpha, GLenum dstAlpha)
 {
 #ifdef GLSM_DEBUG
    log_cb(RETRO_LOG_INFO, "glBlendFuncSeparate.\n");
 #endif
    glsm_ctl(GLSM_CTL_IMM_VBO_DRAW, NULL);
    gl_state.blendfunc_separate.used     = true;
-   gl_state.blendfunc_separate.srcRGB   = sfactor;
+   gl_state.blendfunc_separate.srcRGB   = srcRGB;
-   gl_state.blendfunc_separate.dstRGB   = dfactor;
+   gl_state.blendfunc_separate.dstRGB   = dstRGB;
-   gl_state.blendfunc_separate.srcAlpha = sfactor;
+   gl_state.blendfunc_separate.srcAlpha = srcAlpha;
-   gl_state.blendfunc_separate.dstAlpha = dfactor;
+   gl_state.blendfunc_separate.dstAlpha = dstAlpha;
-   glBlendFunc(sfactor, dfactor);
+   glBlendFuncSeparate(srcRGB, dstRGB, srcAlpha, dstAlpha);
 }
 
 /*
@@ -1030,7 +1030,7 @@ void rglBindFragDataLocation(GLuint program, GLuint colorNumber,
 #ifdef GLSM_DEBUG
    log_cb(RETRO_LOG_INFO, "glBindFragDataLocation.\n");
 #endif
-#if !defined(HAVE_OPENGLES2)
+#if !defined(HAVE_OPENGLES2) && !defined(HAVE_OPENGLES3)
    glBindFragDataLocation(program, colorNumber, name);
 #endif
 }

libretro-common/include/glsm/glsm.h

@@ -31,7 +31,7 @@
 
 RETRO_BEGIN_DECLS
 
-#ifdef HAVE_OPENGLES2
+#if defined(HAVE_OPENGLES2) || defined(HAVE_OPENGLES3)
 typedef double GLdouble;
 typedef double GLclampd;
 #endif

libretro_options.h

@@ -1,13 +1,22 @@
 #ifndef LIBRETRO_OPTIONS_H__
 #define LIBRETRO_OPTIONS_H__
 
+#ifdef HAVE_OPENGLES3
+#define MEDNAFEN_CORE_RENDERER "-GLES3"
+#else
+#define MEDNAFEN_CORE_RENDERER ""
+#endif
+
+#define MEDNAFEN_CORE_SETVERSION "0.9.44.1"
+
 #define MEDNAFEN_CORE_NAME_MODULE "psx"
 #ifdef HAVE_HW
 #define MEDNAFEN_CORE_NAME "Beetle PSX HW"
+#define MEDNAFEN_CORE_VERSION MEDNAFEN_CORE_SETVERSION MEDNAFEN_CORE_RENDERER
 #else
 #define MEDNAFEN_CORE_NAME "Beetle PSX"
+#define MEDNAFEN_CORE_VERSION MEDNAFEN_CORE_SETVERSION
 #endif
-#define MEDNAFEN_CORE_VERSION "0.9.44.1"
 #define MEDNAFEN_CORE_EXTENSIONS "exe|cue|toc|ccd|m3u|pbp|chd"
 #define MEDNAFEN_CORE_GEOMETRY_BASE_W 320
 #define MEDNAFEN_CORE_GEOMETRY_BASE_H 240

rsx/rsx_lib_gl.cpp

@@ -61,7 +61,7 @@
 #include "libretro.h"
 #include "libretro_options.h"
 
-#if 0 || defined(__APPLE__)
+#if 0 || defined(__APPLE__) || defined(HAVE_OPENGLES3)
 #define NEW_COPY_RECT
 static const GLushort indices[6] = {0, 1, 2, 2, 1, 3};
 #else
@@ -706,7 +706,13 @@ static void DrawBuffer_map__no_bind(DrawBuffer<T> *drawbuffer)
          offset_bytes,
          buffer_size,
          GL_MAP_WRITE_BIT |
-         GL_MAP_INVALIDATE_RANGE_BIT);
+#ifdef EMSCRIPTEN
+         // in emscripten, glMapBufferRange is only supported when access is MAP_WRITE|INVALIDATE_BUFFER
+         GL_MAP_INVALIDATE_BUFFER_BIT
+#else
+         GL_MAP_INVALIDATE_RANGE_BIT
+#endif
+         );
 
    assert(m != NULL);
 
@@ -799,6 +805,7 @@ static void DrawBuffer_bind_attributes(DrawBuffer<T> *drawbuffer)
                   element_size,
                   (GLvoid*)attr.offset);
             break;
+#ifndef HAVE_OPENGLES3
          case GL_DOUBLE:
             glVertexAttribLPointer( index,
                   attr.components,
@@ -806,6 +813,7 @@ static void DrawBuffer_bind_attributes(DrawBuffer<T> *drawbuffer)
                   element_size,
                   (GLvoid*)attr.offset);
             break;
+#endif
       }
    }
 }
@@ -885,10 +893,18 @@ static void Framebuffer_init(struct Framebuffer *fb,
 
    glBindFramebuffer(GL_DRAW_FRAMEBUFFER, fb->id);
 
+#ifdef HAVE_OPENGLES3
+   glFramebufferTexture2D( GL_DRAW_FRAMEBUFFER,
+                           GL_COLOR_ATTACHMENT0,
+                           GL_TEXTURE_2D,
+                           color_texture->id,
+                           0);
+#else
    glFramebufferTexture(   GL_DRAW_FRAMEBUFFER,
                            GL_COLOR_ATTACHMENT0,
                            color_texture->id,
                            0);
+#endif
 
    GLenum col_attach_0 = GL_COLOR_ATTACHMENT0;
 
@@ -983,10 +999,18 @@ static void GlRenderer_draw(GlRenderer *renderer)
    /* Bind the out framebuffer */
    Framebuffer_init(&_fb, &renderer->fb_out);
 
+#ifdef HAVE_OPENGLES3
+   glFramebufferTexture2D( GL_DRAW_FRAMEBUFFER,
+         GL_DEPTH_STENCIL_ATTACHMENT,
+         GL_TEXTURE_2D,
+         renderer->fb_out_depth.id,
+         0);
+#else
    glFramebufferTexture(   GL_DRAW_FRAMEBUFFER,
          GL_DEPTH_STENCIL_ATTACHMENT,
          renderer->fb_out_depth.id,
          0);
+#endif
 
    glClear(GL_DEPTH_BUFFER_BIT);
 
@@ -1117,7 +1141,19 @@ static void GlRenderer_upload_textures(
          (GLsizei) dimensions[0],
          (GLsizei) dimensions[1],
          GL_RGBA,
+#ifdef HAVE_OPENGLES3
+         GL_UNSIGNED_SHORT_5_5_5_1,
+         // bits are always in the order that they show
+         // REV indicates the channels are in reversed order
+         // RGBA
+         // 16 bit unsigned short: R5 G5 B5 A1
+         // RRRRRGGGGGBBBBBA
+#else
          GL_UNSIGNED_SHORT_1_5_5_5_REV,
+         // ABGR
+         // 16 bit unsigned short: A1 B5 G5 R5
+         // ABBBBBGGGGGRRRRR
+#endif
          (void*)pixel_buffer);
 
    uint16_t x_start    = top_left[0];
@@ -1152,7 +1188,9 @@ static void GlRenderer_upload_textures(
 
    glDisable(GL_SCISSOR_TEST);
    glDisable(GL_BLEND);
+#ifndef HAVE_OPENGLES3
    glPolygonMode(GL_FRONT_AND_BACK, GL_FILL);
+#endif
 
    /* Bind the output framebuffer */
    Framebuffer _fb;
@@ -1161,7 +1199,9 @@ static void GlRenderer_upload_textures(
    if (!DRAWBUFFER_IS_EMPTY(renderer->image_load_buffer))
       DrawBuffer_draw(renderer->image_load_buffer, GL_TRIANGLE_STRIP);
 
+#ifndef HAVE_OPENGLES3
    glPolygonMode(GL_FRONT_AND_BACK, renderer->command_polygon_mode);
+#endif
    glEnable(GL_SCISSOR_TEST);
 
 #ifdef DEBUG
@@ -1404,7 +1444,9 @@ static bool GlRenderer_new(GlRenderer *renderer, DrawConfig config)
       DrawBuffer_enable_attribute(command_buffer, "dither");
    }
 
+#ifndef HAVE_OPENGLES3
    GLenum command_draw_mode = wireframe ? GL_LINE : GL_FILL;
+#endif
 
    if (command_buffer->program)
    {
@@ -1445,7 +1487,9 @@ static bool GlRenderer_new(GlRenderer *renderer, DrawConfig config)
    renderer->vertex_index_pos = 0;
    renderer->command_draw_mode = GL_TRIANGLES;
    renderer->semi_transparency_mode =  SemiTransparencyMode_Average;
+#ifndef HAVE_OPENGLES3
    renderer->command_polygon_mode = command_draw_mode;
+#endif
    renderer->output_buffer = output_buffer;
    renderer->image_load_buffer = image_load_buffer;
    renderer->config = config;
@@ -1917,7 +1961,9 @@ static bool retro_refresh_variables(GlRenderer *renderer)
       glUniform1ui(renderer->command_buffer->program->uniforms["dither_scaling"], dither_scaling);
    }
 
+#ifndef HAVE_OPENGLES3
    renderer->command_polygon_mode = wireframe ? GL_LINE : GL_FILL;
+#endif
 
    glLineWidth((GLfloat) upscaling);
 
@@ -2479,7 +2525,9 @@ void rsx_gl_prepare_frame(void)
    /* In case we're upscaling we need to increase the line width
     * proportionally */
    glLineWidth((GLfloat)renderer->internal_upscaling);
+#ifndef HAVE_OPENGLES3
    glPolygonMode(GL_FRONT_AND_BACK, renderer->command_polygon_mode);
+#endif
    glEnable(GL_SCISSOR_TEST);
    glEnable(GL_DEPTH_TEST);
    glDepthFunc(GL_LEQUAL);
@@ -2568,7 +2616,9 @@ void rsx_gl_finalize_frame(const void *fb, unsigned width,
    bind_libretro_framebuffer(renderer);
 
    glDisable(GL_SCISSOR_TEST);
+#ifndef HAVE_OPENGLES3
    glPolygonMode(GL_FRONT_AND_BACK, GL_FILL);
+#endif
    glDisable(GL_DEPTH_TEST);
    glDisable(GL_BLEND);
 
@@ -2662,7 +2712,9 @@ void rsx_gl_finalize_frame(const void *fb, unsigned width,
 
       glDisable(GL_SCISSOR_TEST);
       glDisable(GL_BLEND);
+#ifndef HAVE_OPENGLES3
       glPolygonMode(GL_FRONT_AND_BACK, GL_FILL);
+#endif
 
       Framebuffer_init(&_fb, &renderer->fb_texture);
 
@@ -3184,7 +3236,11 @@ void rsx_gl_load_image(
          dimensions,
          (size_t) VRAM_WIDTH_PIXELS,
          GL_RGBA,
+#ifdef HAVE_OPENGLES3
+         GL_UNSIGNED_SHORT_5_5_5_1,
+#else
          GL_UNSIGNED_SHORT_1_5_5_5_REV,
+#endif
          vram);
 
    uint16_t x_start    = top_left[0];
@@ -3216,7 +3272,9 @@ void rsx_gl_load_image(
 
    glDisable(GL_SCISSOR_TEST);
    glDisable(GL_BLEND);
+#ifndef HAVE_OPENGLES3
    glPolygonMode(GL_FRONT_AND_BACK, GL_FILL);
+#endif
 
    /* Bind the output framebuffer */
    Framebuffer_init(&_fb, &renderer->fb_out);
@@ -3224,7 +3282,9 @@ void rsx_gl_load_image(
    if (!DRAWBUFFER_IS_EMPTY(renderer->image_load_buffer))
       DrawBuffer_draw(renderer->image_load_buffer, GL_TRIANGLE_STRIP);
 
+#ifndef HAVE_OPENGLES3
    glPolygonMode(GL_FRONT_AND_BACK, renderer->command_polygon_mode);
+#endif
    glEnable(GL_SCISSOR_TEST);
 
 #ifdef DEBUG
@@ -3281,10 +3341,18 @@ void rsx_gl_fill_rect(
       Framebuffer _fb;
       Framebuffer_init(&_fb, &renderer->fb_out);
 
+#ifdef HAVE_OPENGLES3
+      glFramebufferTexture2D(GL_DRAW_FRAMEBUFFER,
+            GL_DEPTH_STENCIL_ATTACHMENT,
+            GL_TEXTURE_2D,
+            renderer->fb_out_depth.id,
+            0);
+#else
       glFramebufferTexture(GL_DRAW_FRAMEBUFFER,
             GL_DEPTH_STENCIL_ATTACHMENT,
             renderer->fb_out_depth.id,
             0);
+#endif
 
       glClearColor(   (float) col[0] / 255.0,
             (float) col[1] / 255.0,
@@ -3360,10 +3428,18 @@ void rsx_gl_copy_rect(
 
    glGenFramebuffers(1, &fb);
    glBindFramebuffer(GL_READ_FRAMEBUFFER, fb);
+#ifdef HAVE_OPENGLES3
+   glFramebufferTexture2D(GL_READ_FRAMEBUFFER,
+         GL_COLOR_ATTACHMENT0,
+         GL_TEXTURE_2D,
+         renderer->fb_out.id,
+         0);
+#else
    glFramebufferTexture(GL_READ_FRAMEBUFFER,
          GL_COLOR_ATTACHMENT0,
          renderer->fb_out.id,
          0);
+#endif
 
    glReadBuffer(GL_COLOR_ATTACHMENT0);
 
@@ -3371,6 +3447,7 @@ void rsx_gl_copy_rect(
     * GL_TEXTURE_2D? Something tells me this is undefined
     * behaviour. I could use glReadPixels and glWritePixels instead
     * or something like that. */
+   /* former seems to work just fine on GLES 3.0 */
    glBindTexture(GL_TEXTURE_2D, renderer->fb_out.id);
    glCopyTexSubImage2D( GL_TEXTURE_2D, 0, new_dst_x, new_dst_y,
                         new_src_x, new_src_y, new_w, new_h);

rsx/shaders_gl/command_fragment.glsl.h

@@ -16,7 +16,7 @@
 #define command_fragment_name_ command_fragment
 #endif
 
-static const char * command_fragment_name_ = GLSL(
+static const char * command_fragment_name_ = GLSL_FRAGMENT(
 uniform sampler2D fb_texture;
 
 // Scaling to apply to the dither pattern
@@ -73,7 +73,17 @@ uint rebuild_psx_color(vec4 color) {
   uint g = uint(floor(color.g * 31. + 0.5));
   uint b = uint(floor(color.b * 31. + 0.5));
 
+)
+#ifdef HAVE_OPENGLES3
+STRINGIZE(
+  return (r << 11) | (g << 6) | (b << 1) | a;
+)
+#else
+STRINGIZE(
   return (a << 15) | (b << 10) | (g << 5) | r;
+)
+#endif
+STRINGIZE(
 }
 
 // Texture color 0x0000 is special in the Playstation GPU, it denotes
@@ -84,6 +94,20 @@ bool is_transparent(vec4 texel) {
   return rebuild_psx_color(texel) == 0U;
 }
 
+// reinterpret 5551 color for GLES (doesn't support 1555 REV)
+vec4 reinterpret_color(vec4 color) {
+  // rebuild as 5551
+  uint pre_bits = rebuild_psx_color(color);
+
+  // interpret as 1555
+  float a = float((pre_bits & 0x8000U) >> 15) / 31.;
+  float b = float((pre_bits & 0x7C00U) >> 10) / 31.;
+  float g = float((pre_bits & 0x3E0U) >> 5) / 31.;
+  float r = float(pre_bits & 0x1FU) / 31.;
+
+  return vec4(r, g, b, a);
+}
+
 // PlayStation dithering pattern. The offset is selected based on the
 // pixel position in VRAM, by blocks of 4x4 pixels. The value is added
 // to the 8bit color components before they're truncated to 5 bits.
@@ -157,7 +181,18 @@ vec4 sample_texel(vec2 coords) {
       // Look up the real color for the texel in the CLUT
       texel = vram_get_pixel(clut_x, clut_y);
    }
+
+)
+#ifdef HAVE_OPENGLES3
+STRINGIZE(
+   return reinterpret_color(texel);
+)
+#else
+STRINGIZE(
    return texel;
+)
+#endif
+STRINGIZE(
 }
 )
 
@@ -788,7 +823,7 @@ vec4 get_texel_jinc2(out float opacity)
 STRINGIZE(
 void main() {
    vec4 color;
-   float opacity=1;
+   float opacity=1.;
    
       if (frag_texture_blend_mode == BLEND_MODE_NO_TEXTURE)
       {

rsx/shaders_gl/command_vertex.glsl.h

@@ -7,7 +7,7 @@
 #define command_vertex_name_ command_vertex
 #endif
 
-static const char * command_vertex_name_ = GLSL(
+static const char * command_vertex_name_ = GLSL_VERTEX(
 // Vertex shader for rendering GPU draw commands in the framebuffer
 in vec4 position;
 in uvec3 color;
@@ -55,8 +55,8 @@ void main() {
    // Convert VRAM coordinates (0;1023, 0;511) into OpenGL coordinates
    // (-1;1, -1;1)
    float wpos = position.w;
-   float xpos = (pos.x / 512) - 1.0;
+   float xpos = (pos.x / 512.) - 1.0;
-   float ypos = (pos.y / 256) - 1.0;
+   float ypos = (pos.y / 256.) - 1.0;
 
    // position.z increases as the primitives near the camera so we
    // reverse the order to match the common GL convention

rsx/shaders_gl/image_load_fragment.glsl.h

@@ -1,6 +1,6 @@
 #include "shaders_common.h"
 
-static const char *image_load_fragment = GLSL(
+static const char *image_load_fragment = GLSL_FRAGMENT(
       uniform sampler2D fb_texture;
       uniform uint internal_upscaling;
       in vec2 frag_fb_coord;
@@ -12,6 +12,7 @@ static const char *image_load_fragment = GLSL(
       }
 
       void main() {
+      // GLES 5551 note: color reinterpretation can be done here
       frag_color = vram_get_pixel(int(frag_fb_coord.x), int(frag_fb_coord.y));
       }
 );

rsx/shaders_gl/image_load_vertex.glsl.h

@@ -1,6 +1,6 @@
 #include "shaders_common.h"
 
-static const char *image_load_vertex = GLSL(
+static const char *image_load_vertex = GLSL_VERTEX(
       // Vertex shader for uploading textures from the VRAM texture buffer
       // into the output framebuffer
 
@@ -10,8 +10,8 @@ static const char *image_load_vertex = GLSL(
 
       void main() {
       // Convert VRAM position into OpenGL coordinates
-      float xpos = (float(position.x) / 512) - 1.0;
+      float xpos = (float(position.x) / 512.) - 1.0;
-      float ypos = (float(position.y) / 256) - 1.0;
+      float ypos = (float(position.y) / 256.) - 1.0;
 
       gl_Position.xyzw = vec4(xpos, ypos, 0.0, 1.0);
 

rsx/shaders_gl/output_fragment.glsl.h

@@ -1,6 +1,6 @@
 #include "shaders_common.h"
 
-static const char *output_fragment = GLSL(
+static const char *output_fragment = GLSL_FRAGMENT(
    // We're sampling from the internal framebuffer texture
    uniform sampler2D fb;
    // Framebuffer sampling: 0: Normal 16bpp mode, 1: Use 24bpp mode
@@ -24,7 +24,17 @@ static const char *output_fragment = GLSL(
       uint g = uint(floor(color.g * 31. + 0.5));
       uint b = uint(floor(color.b * 31. + 0.5));
 
+)
+#ifdef HAVE_OPENGLES3
+STRINGIZE(
+      return (r << 11) | (g << 6) | (b << 1) | a;
+)
+#else
+STRINGIZE(
       return (a << 15) | (b << 10) | (g << 5) | r;
+)
+#endif
+STRINGIZE(
    }
 
    void main() {
@@ -35,6 +45,7 @@ static const char *output_fragment = GLSL(
          // texture. The alpha/mask bit is ignored here.
 	vec2 off = vec2(offset) / vec2(1024., 512.);
 
+	// GLES 5551 note: color reinterpretation shouldn't be done here
 	color = texture(fb, frag_fb_coord + off).rgb;
       } else {
          // In this mode we have to interpret the framebuffer as containing

rsx/shaders_gl/output_vertex.glsl.h

@@ -1,6 +1,6 @@
 #include "shaders_common.h"
 
-static const char *output_vertex = GLSL(
+static const char *output_vertex = GLSL_VERTEX(
    // Vertex shader for rendering GPU draw commands in the framebuffer
    in vec2 position;
    in uvec2 fb_coord;
@@ -12,8 +12,8 @@ static const char *output_vertex = GLSL(
 
       // Convert the PlayStation framebuffer coordinate into an OpenGL
       // texture coordinate
-      float fb_x_coord = float(fb_coord.x) / 1024;
+      float fb_x_coord = float(fb_coord.x) / 1024.;
-      float fb_y_coord = float(fb_coord.y) / 512;
+      float fb_y_coord = float(fb_coord.y) / 512.;
 
       frag_fb_coord = vec2(fb_x_coord, fb_y_coord);
    }

rsx/shaders_gl/shaders_common.h

@@ -1,7 +1,13 @@
 #ifndef _SHADERS_COMMON
 #define _SHADERS_COMMON
 
-#define GLSL(src) "#version 330 core\n" #src
+#ifdef HAVE_OPENGLES3
+#define GLSL_VERTEX(src) "#version 300 es\n" #src
+#define GLSL_FRAGMENT(src) "#version 300 es\n#ifdef GL_ES\n#ifdef GL_FRAGMENT_PRECISION_HIGH\nprecision highp float;\n#else\nprecision mediump float;\n#endif\n#endif\n" #src
+#else
+#define GLSL_VERTEX(src) "#version 330 core\n" #src
+#define GLSL_FRAGMENT(src) "#version 330 core\n" #src
+#endif
 #define STRINGIZE(src) #src
 
 #endif