Simplify shaders

Cocoa/GBGLShader.m

@@ -50,7 +50,7 @@ void main(void) {\n\
         // Attributes
         position_attribute = glGetAttribLocation(program, "aPosition");
         // Uniforms
-        resolution_uniform = glGetUniformLocation(program, "uResolution");
+        resolution_uniform = glGetUniformLocation(program, "output_resolution");
 
         glGenTextures(1, &texture);
         glBindTexture(GL_TEXTURE_2D, texture);
@@ -68,9 +68,9 @@ void main(void) {\n\
         glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
         glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
         glBindTexture(GL_TEXTURE_2D, 0);
-        previous_texture_uniform = glGetUniformLocation(program, "previousImage");
+        previous_texture_uniform = glGetUniformLocation(program, "previous_image");
 
-        mix_previous_uniform = glGetUniformLocation(program, "uMixPrevious");
+        mix_previous_uniform = glGetUniformLocation(program, "mix_previous");
 
         // Configure OpenGL
         [self configureOpenGL];

Makefile

@@ -286,7 +286,7 @@ $(BIN)/SDL/background.bmp: SDL/background.bmp
 	cp -f $^ $@
 
 $(BIN)/SDL/Shaders: Shaders
-	-@$(MKDIR) -p $(dir $@)
+	-@$(MKDIR) -p $@
 	cp -rf Shaders/*.fsh $@
 
 # Boot ROMs

SDL/shader.c

@@ -109,8 +109,8 @@ bool init_shader_with_name(shader_t *shader, const char *name)
     // Attributes
     shader->position_attribute = glGetAttribLocation(shader->program, "aPosition");
     // Uniforms
-    shader->resolution_uniform = glGetUniformLocation(shader->program, "uResolution");
+    shader->resolution_uniform = glGetUniformLocation(shader->program, "output_resolution");
-    shader->origin_uniform = glGetUniformLocation(shader->program, "uOrigin");
+    shader->origin_uniform = glGetUniformLocation(shader->program, "origin");
 
     glGenTextures(1, &shader->texture);
     glBindTexture(GL_TEXTURE_2D, shader->texture);
@@ -128,9 +128,9 @@ bool init_shader_with_name(shader_t *shader, const char *name)
     glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
     glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
     glBindTexture(GL_TEXTURE_2D, 0);
-    shader->previous_texture_uniform = glGetUniformLocation(shader->program, "previousImage");
+    shader->previous_texture_uniform = glGetUniformLocation(shader->program, "previous_image");
     
-    shader->mix_previous_uniform = glGetUniformLocation(shader->program, "uMixPrevious");
+    shader->mix_previous_uniform = glGetUniformLocation(shader->program, "mix_previous");
     
     // Program
     

Shaders/AAOmniScaleLegacy.fsh

@@ -4,14 +4,14 @@ float quickDistance(vec4 a, vec4 b)
     return abs(a.x - b.x) + abs(a.y - b.y) + abs(a.z - b.z);
 }
 
-vec4 omniScale(sampler2D image, vec2 texCoord)
+vec4 omniScale(sampler2D image, vec2 position)
 {
-    vec2 pixel = texCoord * textureDimensions - vec2(0.5, 0.5);
+    vec2 pixel = position * input_resolution - vec2(0.5, 0.5);
 
-    vec4 q11 = texture(image, (floor(pixel) + 0.5) / textureDimensions);
+    vec4 q11 = texture(image, (floor(pixel) + 0.5) / input_resolution);
-    vec4 q12 = texture(image, (vec2(floor(pixel.x), ceil(pixel.y)) + 0.5) / textureDimensions);
+    vec4 q12 = texture(image, (vec2(floor(pixel.x), ceil(pixel.y)) + 0.5) / input_resolution);
-    vec4 q21 = texture(image, (vec2(ceil(pixel.x), floor(pixel.y)) + 0.5) / textureDimensions);
+    vec4 q21 = texture(image, (vec2(ceil(pixel.x), floor(pixel.y)) + 0.5) / input_resolution);
-    vec4 q22 = texture(image, (ceil(pixel) + 0.5) / textureDimensions);
+    vec4 q22 = texture(image, (ceil(pixel) + 0.5) / input_resolution);
 
     vec2 pos = fract(pixel);
 
@@ -25,7 +25,7 @@ vec4 omniScale(sampler2D image, vec2 texCoord)
         int diagonalBias = 0;
         for (float y = -1.0; y < 3.0; y++) {
             for (float x = -1.0; x < 3.0; x++) {
-                vec4 color = texture(image, (pixel + vec2(x, y)) / textureDimensions);
+                vec4 color = texture(image, (pixel + vec2(x, y)) / input_resolution);
                 if (color == q11) diagonalBias++;
                 if (color == q12) diagonalBias--;
             }
@@ -104,16 +104,15 @@ vec4 omniScale(sampler2D image, vec2 texCoord)
     return q22;
 }
 
-vec4 scale(sampler2D image)
+vec4 scale(sampler2D image, vec2 position)
 {
-    vec2 texCoord = vec2(gl_FragCoord.x, uResolution.y - gl_FragCoord.y) / uResolution;
+    vec2 pixel = vec2(1.0, 1.0) / output_resolution;
-    vec2 pixel = vec2(1.0, 1.0) / uResolution;
     // 4-pixel super sampling
 
-    vec4 q11 = omniScale(image, texCoord + pixel * vec2(-0.25, -0.25));
+    vec4 q11 = omniScale(image, position + pixel * vec2(-0.25, -0.25));
-    vec4 q21 = omniScale(image, texCoord + pixel * vec2(+0.25, -0.25));
+    vec4 q21 = omniScale(image, position + pixel * vec2(+0.25, -0.25));
-    vec4 q12 = omniScale(image, texCoord + pixel * vec2(-0.25, +0.25));
+    vec4 q12 = omniScale(image, position + pixel * vec2(-0.25, +0.25));
-    vec4 q22 = omniScale(image, texCoord + pixel * vec2(+0.25, +0.25));
+    vec4 q22 = omniScale(image, position + pixel * vec2(+0.25, +0.25));
 
     return (q11 + q21 + q12 + q22) / 4.0;
 }

Shaders/AAScale2x.fsh

@@ -1,23 +1,22 @@
-vec4 scale2x(sampler2D image)
+vec4 scale2x(sampler2D image, vec2 position)
 {
     // o = offset, the width of a pixel
-    vec2 o = 1.0 / textureDimensions;
+    vec2 o = 1.0 / input_resolution;
-    vec2 texCoord = vec2(gl_FragCoord.x, uResolution.y - gl_FragCoord.y) / uResolution;
     
     // texel arrangement
     // A B C
     // D E F
     // G H I
-    vec4 A = texture(image, texCoord + vec2( -o.x,  o.y));
+    vec4 A = texture(image, position + vec2( -o.x,  o.y));
-    vec4 B = texture(image, texCoord + vec2(    0,  o.y));
+    vec4 B = texture(image, position + vec2(    0,  o.y));
-    vec4 C = texture(image, texCoord + vec2(  o.x,  o.y));
+    vec4 C = texture(image, position + vec2(  o.x,  o.y));
-    vec4 D = texture(image, texCoord + vec2( -o.x,    0));
+    vec4 D = texture(image, position + vec2( -o.x,    0));
-    vec4 E = texture(image, texCoord + vec2(    0,    0));
+    vec4 E = texture(image, position + vec2(    0,    0));
-    vec4 F = texture(image, texCoord + vec2(  o.x,    0));
+    vec4 F = texture(image, position + vec2(  o.x,    0));
-    vec4 G = texture(image, texCoord + vec2( -o.x, -o.y));
+    vec4 G = texture(image, position + vec2( -o.x, -o.y));
-    vec4 H = texture(image, texCoord + vec2(    0, -o.y));
+    vec4 H = texture(image, position + vec2(    0, -o.y));
-    vec4 I = texture(image, texCoord + vec2(  o.x, -o.y));
+    vec4 I = texture(image, position + vec2(  o.x, -o.y));
-    vec2 p = texCoord * textureDimensions;
+    vec2 p = position * input_resolution;
     // p = the position within a pixel [0...1]
     p = fract(p);
     if (p.x > .5) {
@@ -39,9 +38,7 @@ vec4 scale2x(sampler2D image)
     }
 }
 
-vec4 scale(sampler2D image)
+vec4 scale(sampler2D image, vec2 position)
 {
-    vec2 texCoord = vec2(gl_FragCoord.x, uResolution.y - gl_FragCoord.y) / uResolution;
+    return mix(texture(image, position), scale2x(image, position), 0.5);
-
-    return mix(texture(image, texCoord), scale2x(image), 0.5);
 }

Shaders/AAScale4x.fsh

@@ -1,21 +1,21 @@
-vec4 scale2x(sampler2D image, vec2 texCoord)
+vec4 scale2x(sampler2D image, vec2 position)
 {
     // o = offset, the width of a pixel
-    vec2 o = 1.0 / textureDimensions;
+    vec2 o = 1.0 / input_resolution;
     // texel arrangement
     // A B C
     // D E F
     // G H I
-    vec4 A = texture(image, texCoord + vec2( -o.x,  o.y));
+    vec4 A = texture(image, position + vec2( -o.x,  o.y));
-    vec4 B = texture(image, texCoord + vec2(    0,  o.y));
+    vec4 B = texture(image, position + vec2(    0,  o.y));
-    vec4 C = texture(image, texCoord + vec2(  o.x,  o.y));
+    vec4 C = texture(image, position + vec2(  o.x,  o.y));
-    vec4 D = texture(image, texCoord + vec2( -o.x,    0));
+    vec4 D = texture(image, position + vec2( -o.x,    0));
-    vec4 E = texture(image, texCoord + vec2(    0,    0));
+    vec4 E = texture(image, position + vec2(    0,    0));
-    vec4 F = texture(image, texCoord + vec2(  o.x,    0));
+    vec4 F = texture(image, position + vec2(  o.x,    0));
-    vec4 G = texture(image, texCoord + vec2( -o.x, -o.y));
+    vec4 G = texture(image, position + vec2( -o.x, -o.y));
-    vec4 H = texture(image, texCoord + vec2(    0, -o.y));
+    vec4 H = texture(image, position + vec2(    0, -o.y));
-    vec4 I = texture(image, texCoord + vec2(  o.x, -o.y));
+    vec4 I = texture(image, position + vec2(  o.x, -o.y));
-    vec2 p = texCoord * textureDimensions;
+    vec2 p = position * input_resolution;
     // p = the position within a pixel [0...1]
     p = fract(p);
     if (p.x > .5) {
@@ -37,32 +37,31 @@ vec4 scale2x(sampler2D image, vec2 texCoord)
     }
 }
 
-vec4 aaScale2x(sampler2D image, vec2 texCoord)
+vec4 aaScale2x(sampler2D image, vec2 position)
 {
-    return mix(texture(image, texCoord), scale2x(image, texCoord), 0.5);
+    return mix(texture(image, position), scale2x(image, position), 0.5);
 }
 
-vec4 scale(sampler2D image)
+vec4 scale(sampler2D image, vec2 position)
 {
     // o = offset, the width of a pixel
-    vec2 o = 1.0 / (textureDimensions * 2.);
+    vec2 o = 1.0 / (input_resolution * 2.);
-    vec2 texCoord = vec2(gl_FragCoord.x, uResolution.y - gl_FragCoord.y) / uResolution;
     
     // texel arrangement
     // A B C
     // D E F
     // G H I
-    vec4 A = aaScale2x(image, texCoord + vec2( -o.x,  o.y));
+    vec4 A = aaScale2x(image, position + vec2( -o.x,  o.y));
-    vec4 B = aaScale2x(image, texCoord + vec2(    0,  o.y));
+    vec4 B = aaScale2x(image, position + vec2(    0,  o.y));
-    vec4 C = aaScale2x(image, texCoord + vec2(  o.x,  o.y));
+    vec4 C = aaScale2x(image, position + vec2(  o.x,  o.y));
-    vec4 D = aaScale2x(image, texCoord + vec2( -o.x,    0));
+    vec4 D = aaScale2x(image, position + vec2( -o.x,    0));
-    vec4 E = aaScale2x(image, texCoord + vec2(    0,    0));
+    vec4 E = aaScale2x(image, position + vec2(    0,    0));
-    vec4 F = aaScale2x(image, texCoord + vec2(  o.x,    0));
+    vec4 F = aaScale2x(image, position + vec2(  o.x,    0));
-    vec4 G = aaScale2x(image, texCoord + vec2( -o.x, -o.y));
+    vec4 G = aaScale2x(image, position + vec2( -o.x, -o.y));
-    vec4 H = aaScale2x(image, texCoord + vec2(    0, -o.y));
+    vec4 H = aaScale2x(image, position + vec2(    0, -o.y));
-    vec4 I = aaScale2x(image, texCoord + vec2(  o.x, -o.y));
+    vec4 I = aaScale2x(image, position + vec2(  o.x, -o.y));
     vec4 R;
-    vec2 p = texCoord * textureDimensions * 2.;
+    vec2 p = position * input_resolution * 2.;
     // p = the position within a pixel [0...1]
     p = fract(p);
     if (p.x > .5) {

Shaders/Bilinear.fsh

@@ -1,13 +1,11 @@
-vec4 scale(sampler2D image)
+vec4 scale(sampler2D image, vec2 position)
 {
-    vec2 texCoord = vec2(gl_FragCoord.x, uResolution.y - gl_FragCoord.y) / uResolution;
+    vec2 pixel = position * input_resolution - vec2(0.5, 0.5);
 
-    vec2 pixel = texCoord * textureDimensions - vec2(0.5, 0.5);
+    vec4 q11 = texture(image, (floor(pixel) + 0.5) / input_resolution);
-
+    vec4 q12 = texture(image, (vec2(floor(pixel.x), ceil(pixel.y)) + 0.5) / input_resolution);
-    vec4 q11 = texture(image, (floor(pixel) + 0.5) / textureDimensions);
+    vec4 q21 = texture(image, (vec2(ceil(pixel.x), floor(pixel.y)) + 0.5) / input_resolution);
-    vec4 q12 = texture(image, (vec2(floor(pixel.x), ceil(pixel.y)) + 0.5) / textureDimensions);
+    vec4 q22 = texture(image, (ceil(pixel) + 0.5) / input_resolution);
-    vec4 q21 = texture(image, (vec2(ceil(pixel.x), floor(pixel.y)) + 0.5) / textureDimensions);
-    vec4 q22 = texture(image, (ceil(pixel) + 0.5) / textureDimensions);
 
     vec4 r1 = mix(q11, q21, fract(pixel.x));
     vec4 r2 = mix(q12, q22, fract(pixel.x));

Shaders/HQ2x.fsh

@@ -27,31 +27,30 @@ vec4 interp_3px(vec4 c1, float w1, vec4 c2, float w2, vec4 c3, float w3)
     return (c1 * w1 + c2 * w2 + c3 * w3) / (w1 + w2 + w3);
 }
 
-vec4 scale(sampler2D image)
+vec4 scale(sampler2D image, vec2 position)
 {
     // o = offset, the width of a pixel
-    vec2 o = 1.0 / textureDimensions;
+    vec2 o = 1.0 / input_resolution;
-    vec2 texCoord = vec2(gl_FragCoord.x, uResolution.y - gl_FragCoord.y) / uResolution;
     
     /* We always calculate the top left pixel.  If we need a different pixel, we flip the image */
 
     // p = the position within a pixel [0...1]
-    vec2 p = fract(texCoord * textureDimensions);
+    vec2 p = fract(position * input_resolution);
 
     if (p.x > 0.5) o.x = -o.x;
     if (p.y > 0.5) o.y = -o.y;
 
 
 
-    vec4 w0 = texture(image, texCoord + vec2( -o.x, -o.y));
+    vec4 w0 = texture(image, position + vec2( -o.x, -o.y));
-    vec4 w1 = texture(image, texCoord + vec2(    0, -o.y));
+    vec4 w1 = texture(image, position + vec2(    0, -o.y));
-    vec4 w2 = texture(image, texCoord + vec2(  o.x, -o.y));
+    vec4 w2 = texture(image, position + vec2(  o.x, -o.y));
-    vec4 w3 = texture(image, texCoord + vec2( -o.x,    0));
+    vec4 w3 = texture(image, position + vec2( -o.x,    0));
-    vec4 w4 = texture(image, texCoord + vec2(    0,    0));
+    vec4 w4 = texture(image, position + vec2(    0,    0));
-    vec4 w5 = texture(image, texCoord + vec2(  o.x,    0));
+    vec4 w5 = texture(image, position + vec2(  o.x,    0));
-    vec4 w6 = texture(image, texCoord + vec2( -o.x,  o.y));
+    vec4 w6 = texture(image, position + vec2( -o.x,  o.y));
-    vec4 w7 = texture(image, texCoord + vec2(    0,  o.y));
+    vec4 w7 = texture(image, position + vec2(    0,  o.y));
-    vec4 w8 = texture(image, texCoord + vec2(  o.x,  o.y));
+    vec4 w8 = texture(image, position + vec2(  o.x,  o.y));
 
     int pattern = 0;
     if (is_different(w0, w4)) pattern |= 1;

Shaders/LCD.fsh

@@ -2,29 +2,27 @@
 #define COLOR_HIGH 1.0
 #define SCANLINE_DEPTH 0.1
 
-vec4 scale(sampler2D image)
+vec4 scale(sampler2D image, vec2 position)
 {
-    vec2 texCoord = vec2(gl_FragCoord.x, uResolution.y - gl_FragCoord.y) / uResolution;
+    vec2 pos = fract(position * input_resolution);
+    vec2 sub_pos = fract(position * input_resolution * 6);
     
-    vec2 pos = fract(texCoord * textureDimensions);
+    vec4 center = texture(image, position);
-    vec2 sub_pos = fract(texCoord * textureDimensions * 6);
+    vec4 left = texture(image, position - vec2(1.0 / input_resolution.x, 0));
-    
+    vec4 right = texture(image, position + vec2(1.0 / input_resolution.x, 0));
-    vec4 center = texture(image, texCoord);
-    vec4 left = texture(image, texCoord - vec2(1.0 / textureDimensions.x, 0));
-    vec4 right = texture(image, texCoord + vec2(1.0 / textureDimensions.x, 0));
     
     if (pos.y < 1.0 / 6.0) {
-        center = mix(center, texture(image, texCoord + vec2(0, -1.0 / textureDimensions.y)), 0.5 - sub_pos.y / 2.0);
+        center = mix(center, texture(image, position + vec2(0, -1.0 / input_resolution.y)), 0.5 - sub_pos.y / 2.0);
-        left =   mix(left,   texture(image, texCoord + vec2(-1.0 / textureDimensions.x, -1.0 / textureDimensions.y)), 0.5 - sub_pos.y / 2.0);
+        left =   mix(left,   texture(image, position + vec2(-1.0 / input_resolution.x, -1.0 / input_resolution.y)), 0.5 - sub_pos.y / 2.0);
-        right =  mix(right,  texture(image, texCoord + vec2( 1.0 / textureDimensions.x, -1.0 / textureDimensions.y)), 0.5 - sub_pos.y / 2.0);
+        right =  mix(right,  texture(image, position + vec2( 1.0 / input_resolution.x, -1.0 / input_resolution.y)), 0.5 - sub_pos.y / 2.0);
         center *= sub_pos.y * SCANLINE_DEPTH + (1 - SCANLINE_DEPTH);
         left *= sub_pos.y * SCANLINE_DEPTH + (1 - SCANLINE_DEPTH);
         right *= sub_pos.y * SCANLINE_DEPTH + (1 - SCANLINE_DEPTH);
     }
     else if (pos.y > 5.0 / 6.0) {
-        center = mix(center, texture(image, texCoord + vec2(0, 1.0 / textureDimensions.y)), sub_pos.y / 2.0);
+        center = mix(center, texture(image, position + vec2(0, 1.0 / input_resolution.y)), sub_pos.y / 2.0);
-        left =   mix(left,   texture(image, texCoord + vec2(-1.0 / textureDimensions.x, 1.0 / textureDimensions.y)), sub_pos.y / 2.0);
+        left =   mix(left,   texture(image, position + vec2(-1.0 / input_resolution.x, 1.0 / input_resolution.y)), sub_pos.y / 2.0);
-        right =  mix(right,  texture(image, texCoord + vec2( 1.0 / textureDimensions.x, 1.0 / textureDimensions.y)), sub_pos.y / 2.0);
+        right =  mix(right,  texture(image, position + vec2( 1.0 / input_resolution.x, 1.0 / input_resolution.y)), sub_pos.y / 2.0);
         center *= (1.0 - sub_pos.y) * SCANLINE_DEPTH + (1 - SCANLINE_DEPTH);
         left *= (1.0 - sub_pos.y) * SCANLINE_DEPTH + (1 - SCANLINE_DEPTH);
         right *= (1.0 - sub_pos.y) * SCANLINE_DEPTH + (1 - SCANLINE_DEPTH);

Shaders/MasterShader.fsh

@@ -1,27 +1,28 @@
 #version 150
 uniform sampler2D image;
-uniform sampler2D previousImage;
+uniform sampler2D previous_image;
-uniform bool uMixPrevious;
+uniform bool mix_previous;
 
-uniform vec2 uResolution;
+uniform vec2 output_resolution;
-uniform vec2 uOrigin;
+uniform vec2 origin;
-const vec2 textureDimensions = vec2(160, 144);
+const vec2 input_resolution = vec2(160, 144);
 
 out vec4 frag_color;
 
 vec4 modified_frag_cord;
-#define gl_FragCoord modified_frag_cord
 #line 1
 {filter}
-#undef gl_FragCoord
 
-void main() {
+void main()
-    modified_frag_cord = gl_FragCoord - vec4(uOrigin.x, uOrigin.y, 0, 0);
+{
+    vec2 position = gl_FragCoord.xy - origin;
+    position /= output_resolution;
+    position.y = 1 - position.y;
     
-    if (uMixPrevious) {
+    if (mix_previous) {
-        frag_color = mix(scale(image), scale(previousImage), 0.5);
+        frag_color = mix(scale(image, position), scale(previous_image, position), 0.5);
     }
     else {
-        frag_color = scale(image);
+        frag_color = scale(image, position);
     }
 }

Shaders/MasterShader.metal

@@ -3,6 +3,7 @@
 #include <metal_math>
 
 using namespace metal;
+const float4 input_resolution = float4(160, 144);
 
 /* For GLSL compatibility */
 typedef float2 vec2;
@@ -17,7 +18,6 @@ typedef struct {
 // Vertex Function
 vertex rasterizer_data vertex_shader(uint index [[ vertex_id ]],
                                      constant vector_float2 *vertices [[ buffer(0) ]])
-
 {
     rasterizer_data out;
 

Shaders/NearestNeighbor.fsh

@@ -1,6 +1,4 @@
-vec4 scale(sampler2D image)
+vec4 scale(sampler2D image, vec2 position)
 {
-    vec2 texCoord = vec2(gl_FragCoord.x, uResolution.y - gl_FragCoord.y) / uResolution;
+    return texture(image, position);
-
-    return texture(image, texCoord);
 }

Shaders/OmniScale.fsh

@@ -24,16 +24,15 @@ bool is_different(vec4 a, vec4 b)
 
 #define P(m, r) ((pattern & (m)) == (r))
 
-vec4 scale(sampler2D image)
+vec4 scale(sampler2D image, vec2 position)
 {
     // o = offset, the width of a pixel
-    vec2 o = 1.0 / textureDimensions;
+    vec2 o = 1.0 / input_resolution;
-    vec2 texCoord = vec2(gl_FragCoord.x, uResolution.y - gl_FragCoord.y) / uResolution;
     
     /* We always calculate the top left quarter.  If we need a different quarter, we flip our co-ordinates */
 
     // p = the position within a pixel [0...1]
-    vec2 p = fract(texCoord * textureDimensions);
+    vec2 p = fract(position * input_resolution);
 
     if (p.x > 0.5) {
         o.x = -o.x;
@@ -44,17 +43,15 @@ vec4 scale(sampler2D image)
         p.y = 1.0 - p.y;
     }
 
-
+    vec4 w0 = texture(image, position + vec2( -o.x, -o.y));
-
+    vec4 w1 = texture(image, position + vec2(    0, -o.y));
-    vec4 w0 = texture(image, texCoord + vec2( -o.x, -o.y));
+    vec4 w2 = texture(image, position + vec2(  o.x, -o.y));
-    vec4 w1 = texture(image, texCoord + vec2(    0, -o.y));
+    vec4 w3 = texture(image, position + vec2( -o.x,    0));
-    vec4 w2 = texture(image, texCoord + vec2(  o.x, -o.y));
+    vec4 w4 = texture(image, position + vec2(    0,    0));
-    vec4 w3 = texture(image, texCoord + vec2( -o.x,    0));
+    vec4 w5 = texture(image, position + vec2(  o.x,    0));
-    vec4 w4 = texture(image, texCoord + vec2(    0,    0));
+    vec4 w6 = texture(image, position + vec2( -o.x,  o.y));
-    vec4 w5 = texture(image, texCoord + vec2(  o.x,    0));
+    vec4 w7 = texture(image, position + vec2(    0,  o.y));
-    vec4 w6 = texture(image, texCoord + vec2( -o.x,  o.y));
+    vec4 w8 = texture(image, position + vec2(  o.x,  o.y));
-    vec4 w7 = texture(image, texCoord + vec2(    0,  o.y));
-    vec4 w8 = texture(image, texCoord + vec2(  o.x,  o.y));
 
     int pattern = 0;
     if (is_different(w0, w4)) pattern |= 1 << 0;
@@ -83,7 +80,7 @@ vec4 scale(sampler2D image)
         return mix(mix(w0 * 0.375 + w3 * 0.25 + w4 * 0.375, w4 * 0.5 + w3 * 0.5, p.y * 2.0), w4, p.x * 2.0);
     if (P(0x2f,0x2f)) {
         float dist = length(p - vec2(0.5));
-        float pixel_size = length(1.0 / (uResolution / textureDimensions));
+        float pixel_size = length(1.0 / (output_resolution / input_resolution));
         if (dist < 0.5 - pixel_size / 2) {
             return w4;
         }
@@ -102,7 +99,7 @@ vec4 scale(sampler2D image)
     }
     if (P(0xbf,0x37) || P(0xdb,0x13)) {
         float dist = p.x - 2.0 * p.y;
-        float pixel_size = length(1.0 / (uResolution / textureDimensions)) * sqrt(5);
+        float pixel_size = length(1.0 / (output_resolution / input_resolution)) * sqrt(5);
         if (dist > pixel_size / 2) {
             return w1;
         }
@@ -114,7 +111,7 @@ vec4 scale(sampler2D image)
     }
     if (P(0xdb,0x49) || P(0xef,0x6d)) {
         float dist = p.y - 2.0 * p.x;
-        float pixel_size = length(1.0 / (uResolution / textureDimensions)) * sqrt(5);
+        float pixel_size = length(1.0 / (output_resolution / input_resolution)) * sqrt(5);
         if (p.y - 2.0 * p.x > pixel_size / 2) {
             return w3;
         }
@@ -126,7 +123,7 @@ vec4 scale(sampler2D image)
     }
     if (P(0xbf,0x8f) || P(0x7e,0x0e)) {
         float dist = p.x + 2.0 * p.y;
-        float pixel_size = length(1.0 / (uResolution / textureDimensions)) * sqrt(5);
+        float pixel_size = length(1.0 / (output_resolution / input_resolution)) * sqrt(5);
 
         if (dist > 1.0 + pixel_size / 2) {
             return w4;
@@ -150,7 +147,7 @@ vec4 scale(sampler2D image)
 
     if (P(0x7e,0x2a) || P(0xef,0xab)) {
         float dist = p.y + 2.0 * p.x;
-        float pixel_size = length(1.0 / (uResolution / textureDimensions)) * sqrt(5);
+        float pixel_size = length(1.0 / (output_resolution / input_resolution)) * sqrt(5);
 
         if (p.y + 2.0 * p.x > 1.0 + pixel_size / 2) {
             return w4;
@@ -186,7 +183,7 @@ vec4 scale(sampler2D image)
         P(0xbe,0x0a) || P(0xee,0x0a) || P(0x7e,0x0a) || P(0xeb,0x4b) ||
         P(0x3b,0x1b)) {
         float dist = p.x + p.y;
-        float pixel_size = length(1.0 / (uResolution / textureDimensions));
+        float pixel_size = length(1.0 / (output_resolution / input_resolution));
 
         if (dist > 0.5 + pixel_size / 2) {
             return w4;
@@ -214,19 +211,19 @@ vec4 scale(sampler2D image)
         return mix(mix(w4, w3, 0.5 - p.x), mix(w1, w0, 0.5 - p.x), 0.5 - p.y);
 
     float dist = p.x + p.y;
-    float pixel_size = length(1.0 / (uResolution / textureDimensions));
+    float pixel_size = length(1.0 / (output_resolution / input_resolution));
 
     if (dist > 0.5 + pixel_size / 2)
         return w4;
 
     /* We need more samples to "solve" this diagonal */
-    vec4 x0 = texture(image, texCoord + vec2( -o.x * 2.0, -o.y * 2.0));
+    vec4 x0 = texture(image, position + vec2( -o.x * 2.0, -o.y * 2.0));
-    vec4 x1 = texture(image, texCoord + vec2( -o.x      , -o.y * 2.0));
+    vec4 x1 = texture(image, position + vec2( -o.x      , -o.y * 2.0));
-    vec4 x2 = texture(image, texCoord + vec2(  0.0      , -o.y * 2.0));
+    vec4 x2 = texture(image, position + vec2(  0.0      , -o.y * 2.0));
-    vec4 x3 = texture(image, texCoord + vec2(  o.x      , -o.y * 2.0));
+    vec4 x3 = texture(image, position + vec2(  o.x      , -o.y * 2.0));
-    vec4 x4 = texture(image, texCoord + vec2( -o.x * 2.0, -o.y      ));
+    vec4 x4 = texture(image, position + vec2( -o.x * 2.0, -o.y      ));
-    vec4 x5 = texture(image, texCoord + vec2( -o.x * 2.0,  0.0      ));
+    vec4 x5 = texture(image, position + vec2( -o.x * 2.0,  0.0      ));
-    vec4 x6 = texture(image, texCoord + vec2( -o.x * 2.0,  o.y      ));
+    vec4 x6 = texture(image, position + vec2( -o.x * 2.0,  o.y      ));
 
     if (is_different(x0, w4)) pattern |= 1 << 8;
     if (is_different(x1, w4)) pattern |= 1 << 9;

Shaders/OmniScaleLegacy.fsh

@@ -4,16 +4,14 @@ float quickDistance(vec4 a, vec4 b)
     return abs(a.x - b.x) + abs(a.y - b.y) + abs(a.z - b.z);
 }
 
-vec4 scale(sampler2D image)
+vec4 scale(sampler2D image, vec2 position)
 {
-    vec2 texCoord = vec2(gl_FragCoord.x, uResolution.y - gl_FragCoord.y) / uResolution;
+    vec2 pixel = position * input_resolution - vec2(0.5, 0.5);
 
-    vec2 pixel = texCoord * textureDimensions - vec2(0.5, 0.5);
+    vec4 q11 = texture(image, (floor(pixel) + 0.5) / input_resolution);
-
+    vec4 q12 = texture(image, (vec2(floor(pixel.x), ceil(pixel.y)) + 0.5) / input_resolution);
-    vec4 q11 = texture(image, (floor(pixel) + 0.5) / textureDimensions);
+    vec4 q21 = texture(image, (vec2(ceil(pixel.x), floor(pixel.y)) + 0.5) / input_resolution);
-    vec4 q12 = texture(image, (vec2(floor(pixel.x), ceil(pixel.y)) + 0.5) / textureDimensions);
+    vec4 q22 = texture(image, (ceil(pixel) + 0.5) / input_resolution);
-    vec4 q21 = texture(image, (vec2(ceil(pixel.x), floor(pixel.y)) + 0.5) / textureDimensions);
-    vec4 q22 = texture(image, (ceil(pixel) + 0.5) / textureDimensions);
 
     vec2 pos = fract(pixel);
 
@@ -27,7 +25,7 @@ vec4 scale(sampler2D image)
         int diagonalBias = 0;
         for (float y = -1.0; y < 3.0; y++) {
             for (float x = -1.0; x < 3.0; x++) {
-                vec4 color = texture(image, (pixel + vec2(x, y)) / textureDimensions);
+                vec4 color = texture(image, (pixel + vec2(x, y)) / input_resolution);
                 if (color == q11) diagonalBias++;
                 if (color == q12) diagonalBias--;
             }

Shaders/Scale2x.fsh

@@ -1,25 +1,24 @@
 /* Shader implementation of Scale2x is adapted from https://gist.github.com/singron/3161079 */
 
-vec4 scale(sampler2D image)
+vec4 scale(sampler2D image, vec2 position)
 {
     // o = offset, the width of a pixel
-    vec2 o = 1.0 / textureDimensions;
+    vec2 o = 1.0 / input_resolution;
-    vec2 texCoord = vec2(gl_FragCoord.x, uResolution.y - gl_FragCoord.y) / uResolution;
     
     // texel arrangement
     // A B C
     // D E F
     // G H I
-    vec4 A = texture(image, texCoord + vec2( -o.x,  o.y));
+    vec4 A = texture(image, position + vec2( -o.x,  o.y));
-    vec4 B = texture(image, texCoord + vec2(    0,  o.y));
+    vec4 B = texture(image, position + vec2(    0,  o.y));
-    vec4 C = texture(image, texCoord + vec2(  o.x,  o.y));
+    vec4 C = texture(image, position + vec2(  o.x,  o.y));
-    vec4 D = texture(image, texCoord + vec2( -o.x,    0));
+    vec4 D = texture(image, position + vec2( -o.x,    0));
-    vec4 E = texture(image, texCoord + vec2(    0,    0));
+    vec4 E = texture(image, position + vec2(    0,    0));
-    vec4 F = texture(image, texCoord + vec2(  o.x,    0));
+    vec4 F = texture(image, position + vec2(  o.x,    0));
-    vec4 G = texture(image, texCoord + vec2( -o.x, -o.y));
+    vec4 G = texture(image, position + vec2( -o.x, -o.y));
-    vec4 H = texture(image, texCoord + vec2(    0, -o.y));
+    vec4 H = texture(image, position + vec2(    0, -o.y));
-    vec4 I = texture(image, texCoord + vec2(  o.x, -o.y));
+    vec4 I = texture(image, position + vec2(  o.x, -o.y));
-    vec2 p = texCoord * textureDimensions;
+    vec2 p = position * input_resolution;
     // p = the position within a pixel [0...1]
     p = fract(p);
     if (p.x > .5) {

Shaders/Scale4x.fsh

@@ -1,21 +1,21 @@
-vec4 scale2x(sampler2D image, vec2 texCoord)
+vec4 scale2x(sampler2D image, vec2 position)
 {
     // o = offset, the width of a pixel
-    vec2 o = 1.0 / textureDimensions;
+    vec2 o = 1.0 / input_resolution;
     // texel arrangement
     // A B C
     // D E F
     // G H I
-    vec4 A = texture(image, texCoord + vec2( -o.x,  o.y));
+    vec4 A = texture(image, position + vec2( -o.x,  o.y));
-    vec4 B = texture(image, texCoord + vec2(    0,  o.y));
+    vec4 B = texture(image, position + vec2(    0,  o.y));
-    vec4 C = texture(image, texCoord + vec2(  o.x,  o.y));
+    vec4 C = texture(image, position + vec2(  o.x,  o.y));
-    vec4 D = texture(image, texCoord + vec2( -o.x,    0));
+    vec4 D = texture(image, position + vec2( -o.x,    0));
-    vec4 E = texture(image, texCoord + vec2(    0,    0));
+    vec4 E = texture(image, position + vec2(    0,    0));
-    vec4 F = texture(image, texCoord + vec2(  o.x,    0));
+    vec4 F = texture(image, position + vec2(  o.x,    0));
-    vec4 G = texture(image, texCoord + vec2( -o.x, -o.y));
+    vec4 G = texture(image, position + vec2( -o.x, -o.y));
-    vec4 H = texture(image, texCoord + vec2(    0, -o.y));
+    vec4 H = texture(image, position + vec2(    0, -o.y));
-    vec4 I = texture(image, texCoord + vec2(  o.x, -o.y));
+    vec4 I = texture(image, position + vec2(  o.x, -o.y));
-    vec2 p = texCoord * textureDimensions;
+    vec2 p = position * input_resolution;
     // p = the position within a pixel [0...1]
     vec4 R;
     p = fract(p);
@@ -38,26 +38,25 @@ vec4 scale2x(sampler2D image, vec2 texCoord)
     }
 }
 
-vec4 scale(sampler2D image)
+vec4 scale(sampler2D image, vec2 position)
 {
     // o = offset, the width of a pixel
-    vec2 o = 1.0 / (textureDimensions * 2.);
+    vec2 o = 1.0 / (input_resolution * 2.);
-    vec2 texCoord = vec2(gl_FragCoord.x, uResolution.y - gl_FragCoord.y) / uResolution;
     
     // texel arrangement
     // A B C
     // D E F
     // G H I
-    vec4 A = scale2x(image, texCoord + vec2( -o.x,  o.y));
+    vec4 A = scale2x(image, position + vec2( -o.x,  o.y));
-    vec4 B = scale2x(image, texCoord + vec2(    0,  o.y));
+    vec4 B = scale2x(image, position + vec2(    0,  o.y));
-    vec4 C = scale2x(image, texCoord + vec2(  o.x,  o.y));
+    vec4 C = scale2x(image, position + vec2(  o.x,  o.y));
-    vec4 D = scale2x(image, texCoord + vec2( -o.x,    0));
+    vec4 D = scale2x(image, position + vec2( -o.x,    0));
-    vec4 E = scale2x(image, texCoord + vec2(    0,    0));
+    vec4 E = scale2x(image, position + vec2(    0,    0));
-    vec4 F = scale2x(image, texCoord + vec2(  o.x,    0));
+    vec4 F = scale2x(image, position + vec2(  o.x,    0));
-    vec4 G = scale2x(image, texCoord + vec2( -o.x, -o.y));
+    vec4 G = scale2x(image, position + vec2( -o.x, -o.y));
-    vec4 H = scale2x(image, texCoord + vec2(    0, -o.y));
+    vec4 H = scale2x(image, position + vec2(    0, -o.y));
-    vec4 I = scale2x(image, texCoord + vec2(  o.x, -o.y));
+    vec4 I = scale2x(image, position + vec2(  o.x, -o.y));
-    vec2 p = texCoord * textureDimensions * 2.;
+    vec2 p = position * input_resolution * 2.;
     // p = the position within a pixel [0...1]
     p = fract(p);
     if (p.x > .5) {

Shaders/SmoothBilinear.fsh

@@ -1,13 +1,11 @@
-vec4 scale(sampler2D image)
+vec4 scale(sampler2D image, vec2 position)
 {
-    vec2 texCoord = vec2(gl_FragCoord.x, uResolution.y - gl_FragCoord.y) / uResolution;
+    vec2 pixel = position * input_resolution - vec2(0.5, 0.5);
 
-    vec2 pixel = texCoord * textureDimensions - vec2(0.5, 0.5);
+    vec4 q11 = texture(image, (floor(pixel) + 0.5) / input_resolution);
-
+    vec4 q12 = texture(image, (vec2(floor(pixel.x), ceil(pixel.y)) + 0.5) / input_resolution);
-    vec4 q11 = texture(image, (floor(pixel) + 0.5) / textureDimensions);
+    vec4 q21 = texture(image, (vec2(ceil(pixel.x), floor(pixel.y)) + 0.5) / input_resolution);
-    vec4 q12 = texture(image, (vec2(floor(pixel.x), ceil(pixel.y)) + 0.5) / textureDimensions);
+    vec4 q22 = texture(image, (ceil(pixel) + 0.5) / input_resolution);
-    vec4 q21 = texture(image, (vec2(ceil(pixel.x), floor(pixel.y)) + 0.5) / textureDimensions);
-    vec4 q22 = texture(image, (ceil(pixel) + 0.5) / textureDimensions);
 
     vec2 s = smoothstep(0., 1., fract(pixel));