Add Sharp Bilinear Upscale post shader, thanks Silent

assets/shaders/defaultshaders.ini

@@ -243,3 +243,8 @@ SettingDefaultValue1=0.4
 SettingMaxValue1=0.8
 SettingMinValue1=0.3
 SettingStep1=0.05
+[UpscaleSharpBilinear]
+Name=Sharp Bilinear Upscaler
+Fragment=upscale_sharp_bilinear.fsh
+Vertex=upscale_sharp_bilinear.vsh
+OutputResolution=True

assets/shaders/upscale_sharp_bilinear.fsh

@@ -0,0 +1,25 @@
+#ifdef GL_ES
+#extension GL_OES_standard_derivatives : enable
+precision mediump float;
+precision mediump int;
+#endif
+
+uniform sampler2D sampler0;
+varying vec2 v_position;
+
+uniform vec2 u_texelDelta; // (1.0 / bufferWidth, 1.0 / bufferHeight)
+uniform vec2 u_pixelDelta; // (1.0 / targetWidth, 1.0 / targetHeight)
+
+// Returns pixel sharpened to nearest pixel boundary.
+vec2 sharpSample(vec4 texSize, vec2 coord) {
+	vec2 boxSize = clamp(fwidth(coord) * texSize.zw, 1e-5, 1.0);
+	coord = coord * texSize.zw - 0.5 * boxSize;
+	vec2 txOffset = smoothstep(vec2(1.0) - boxSize, vec2(1.0), fract(coord));
+	return (floor(coord) + 0.5 + txOffset) * texSize.xy;
+}
+
+void main() {
+	vec2 sharpPos = sharpSample(vec4(u_texelDelta, 1.0 / u_texelDelta), v_position);
+	vec4 color = texture2D(sampler0, sharpPos);
+	gl_FragColor = color;
+}

assets/shaders/upscale_sharp_bilinear.vsh

@@ -0,0 +1,9 @@
+attribute vec4 a_position;
+attribute vec2 a_texcoord0;
+
+varying vec2 v_position;
+
+void main() {
+	gl_Position = a_position;
+	v_position = a_texcoord0;
+}