Fix compare shader(s)

compare.glsl

@@ -4,16 +4,16 @@
 
 // try isampler2D, ivec4 etc.? Probably not
 uniform vec2 size;
+uniform vec2 offs;
 uniform sampler2D base;
 uniform sampler2D curr;
 
 void main(void)
 {
-	vec2 pos = gl_FragCoord.xy/size;
+	vec2 pos = (gl_FragCoord.xy-offs)/size;
-// 	vec4 color = texture(curr, pos);  // fails for some reason!?
+	pos.y = 1.0 - pos.y;
-// 	vec4 basecolor = texture(base, pos);  // fails too...
+	vec4 color = texture2D(curr, pos);
-// 	color.xyz = abs(color.xyz - basecolor.xyz);
+	vec4 basecolor = texture2D(base, pos);
-// 	gl_FragColor = color;
+	color.xyz = abs(color.xyz - basecolor.xyz);
-// 	gl_FragColor = basecolor;
+	gl_FragColor = color;
-	gl_FragColor = vec4(1.0);
 }

compare_med.glsl

@@ -0,0 +1,20 @@
+// Compute the pixelwise diff between two textures.
+// Computes the diff for each color chanel separately (r, g, b).
+// Assumes both images are not transparent.
+
+// try isampler2D, ivec4 etc.? Probably not
+uniform vec2 size;
+uniform vec2 offs;
+uniform sampler2D base;
+uniform sampler2D curr;
+
+void main(void)
+{
+	vec2 pos = (gl_FragCoord.xy-offs)/size;
+	pos.y = 1.0 - pos.y;
+	vec4 color = texture2D(curr, pos);
+	vec4 basecolor = texture2D(base, pos);
+	color.xyz = color.xyz - basecolor.xyz;
+	color.xyz = (vec3(1.0, 1.0, 1.0) + color.xyz)/2.0;
+	gl_FragColor = color;
+}

src/main.cpp

@@ -14,6 +14,9 @@
  *    - show fitness for individuals?
  *    - show stats for generation?
  * 
+ * 1.5) mating screen
+ *      - 
+ * 
  * 2) fitness screen
  *    - show original image
  *    - show currently evaluated image
@@ -67,7 +70,19 @@ int main() {
 	
 	compshdr.setUniform("base", base);
 	compshdr.setUniform("curr", comp);
-	compshdr.setUniform("size", 240, 240);
+	compshdr.setUniform("size", sf::Vector2f(240, 240));
+	compshdr.setUniform("offs", sf::Vector2f(0, 0));
+	
+	sf::Shader medcompshdr;
+	medcompshdr.loadFromFile("compare_med.glsl", sf::Shader::Fragment);
+	if (!medcompshdr.isAvailable()) {
+		std::cout << "The medshader is not available\n";
+		return 1;
+	}
+	medcompshdr.setUniform("base", comp);
+	medcompshdr.setUniform("curr", base);
+	medcompshdr.setUniform("size", sf::Vector2f(240, 240));
+	medcompshdr.setUniform("offs", sf::Vector2f(240, 0));
 	
 	// Set the resolution parameter (the resoltion is divided to make the fire smaller)
 // 	shader.setParameter("resolution", sf::Vector2f(winW / 2, winH / 2));
@@ -92,7 +107,7 @@ int main() {
 // 		sf::Vector2i mousePos = sf::Mouse::getPosition(window);
 // 		shader.setParameter("mouse", sf::Vector2f(mousePos.x, mousePos.y - winH));
 		
-		// Draw the sprites, one with the shader on it
+		// Draw the sprites
 		window.clear();
 		
 		window.draw(sprbase);
@@ -103,6 +118,9 @@ int main() {
 		sprcomp.setPosition(0, 240);
 		window.draw(sprcomp, &compshdr);
 		
+		sprcomp.setPosition(240, 240);
+		window.draw(sprcomp, &medcompshdr);
+		
 		window.display();
 	}