Added shader subroutine basic handling

BaseGLProject/Loader.h

@@ -390,6 +390,21 @@ public:
 		return uniformMap[uniformName];
 	}
 
+	std::map<std::string, GLuint> _subroutine_map;
+
+	int addSubroutine(GLenum shadertype, const std::string uniformName)
+	{
+		_subroutine_map[uniformName] = glGetSubroutineIndex(programId, shadertype, uniformName.c_str());
+		return _subroutine_map[uniformName];
+	}
+
+	void enableSubroutine(const std::string uniformName)
+	{		
+		use();
+		glUniformSubroutinesuiv(GL_FRAGMENT_SHADER, 1, &_subroutine_map[uniformName]);
+		disable();
+	}
+
 }; // End of class
 
 #endif // SHADER_PROGRAM_HPP

BaseGLProject/MyGLWindow.cpp

@@ -139,6 +139,13 @@ void MyGlWindow::multipassSetup()
 	_multipassManager.bindToFrameBuffer(GL_DEPTH_ATTACHMENT, GL_TEXTURE_2D, "depth_tex");
 
 	_multipassManager.setDrawBuffers();
+
+	_multipassManager.shader.addSubroutine(GL_FRAGMENT_SHADER, "depthing");
+	_multipassManager.shader.addSubroutine(GL_FRAGMENT_SHADER, "blurring");
+	_multipassManager.shader.addSubroutine(GL_FRAGMENT_SHADER, "sharpening");
+	_multipassManager.shader.addSubroutine(GL_FRAGMENT_SHADER, "sepia");
+	_multipassManager.shader.addSubroutine(GL_FRAGMENT_SHADER, "grayscale");
+	_multipassManager.shader.addSubroutine(GL_FRAGMENT_SHADER, "sobel_filter");
 }
 
 void MyGlWindow::setup()
@@ -235,7 +242,7 @@ void MyGlWindow::draw()
 	for (auto it = meshes.begin(); it != meshes.end(); it++)
 		(*it).second->draw(_scnctx);
 	
-	_multipassManager.shader.addUniform("sobel", true);
+	_multipassManager.shader.enableSubroutine("sobel_filter");
 	_multipassManager.drawResultToScreen(_scnctx);
 	//skybox.draw(shaders["Skybox"], _scnctx);
 }

BaseGLProject/Shader.cpp

@@ -19,6 +19,16 @@ void Shader::disable()
 	_program.disable();
 }
 
+int Shader::addSubroutine(GLenum shadertype, const std::string uniformName)
+{
+	return _program.addSubroutine(shadertype, uniformName);
+}
+
+void Shader::enableSubroutine(const std::string uniformName)
+{
+	return _program.enableSubroutine(uniformName);
+}
+
 void Shader::setMaterial(SceneContext ctx)
 {
 	if ((uniformFlags & ShaderFlags::KA_FLAG) == ShaderFlags::KA_FLAG)

BaseGLProject/Shader.h

@@ -40,6 +40,9 @@ public:
 	void enable();
 	void disable();
 
+	int addSubroutine(GLenum shadertype, const std::string uniformName);
+	void enableSubroutine(const std::string uniformName);
+
 	
 public:
 	void setUniforms(SceneContext ctx);	
@@ -79,6 +82,5 @@ private:
 	void setCamera(SceneContext ctx);
 	void setLights(SceneContext ctx);
 	
-private:
 	ShaderProgram _program;
 };

BaseGLProject/textureViewer.frag

@@ -5,12 +5,10 @@ in vec2 uv;
 out vec4 final_color;
 
 uniform sampler2D tex;
-uniform bool depth;
-uniform bool blur;
-uniform bool sharpen;
-uniform bool sepia;
-uniform bool grayscale;
-uniform bool sobel;
+
+
+subroutine vec4 shading_t(vec4 color);
+subroutine uniform shading_t Shading;
 
 const float f = 1.0 / 300.0;
 
@@ -20,45 +18,65 @@ vec2 offsets[9] = vec2[](
 		vec2(-f, -f), vec2(0.0, -f), vec2(f, -f)
 );
 
-float blur_kernel[9] = float[](
-	1.0 / 16, 2.0 / 16, 1.0 / 16,
-	2.0 / 16, 4.0 / 16, 2.0 / 16,
-	1.0 / 16, 2.0 / 16, 1.0 / 16
-);
+subroutine(shading_t)
+vec4 sepia(vec4 color)
+{
+	return vec4(color.r * .393 + color.g * .769 + color.b * .189,
+			   color.r * .349 + color.g * .686 + color.b * .168,
+			   color.r * .272 + color.g * .534 + color.b * .131, 1.0);
+}
 
-float sharp_kernel[9] = float[](
-	-1, -1, -1,
-	-1, 9, -1,
-	-1, -1, -1
-);
+subroutine(shading_t)
+vec4 grayscale(vec4 color)
+{
+	float average = color.r * 0.2126 + color.g * 0.7152 + color.b * 0.0722;
+	return vec4(average, average, average, 1);
+}
 
-float LinearizeDepth(in vec2 uv)
+subroutine(shading_t)
+vec4 depthing(vec4 color)
 {
     float zNear = 0.1f;    //  zNear of your perspective projection
     float zFar  = 2000.0f; // zFar of your perspective projection
-    float depth = texture(tex, uv).x;	
-    return (2.0 * zNear) / (zFar + zNear - depth * (zFar - zNear));
+    float depth = color.x;
+	float r = (2.0 * zNear) / (zFar + zNear - depth * (zFar - zNear));
+    return vec4(r, r, r, 1);
 }
 
-vec3 blurring_func(in vec2 uv)
+subroutine(shading_t)
+vec4 blurring(vec4 color)
 {	
+	float blur_kernel[9] = float[](
+		1.0 / 16, 2.0 / 16, 1.0 / 16,
+		2.0 / 16, 4.0 / 16, 2.0 / 16,
+		1.0 / 16, 2.0 / 16, 1.0 / 16
+	);
+
 	vec3 texblur = vec3(0,0,0);
 	for (int i = 0; i < 9; i++)				
 		texblur += vec3(texture(tex, uv + offsets[i]).rgb * blur_kernel[i]);
 		
-	return texblur;
+	return vec4(texblur, 1);
 }
 
-vec4 sharpening_func(in vec2 uv)
+subroutine(shading_t)
+vec4 sharpening(vec4 color)
 {
-	vec4 texsharp = vec4(0,0,0,0);
-	for (uint i = 0; i < 9; i++)
-		texsharp += texture(tex, uv + offsets[i]).rgba * sharp_kernel[i];
+	float sharp_kernel[9] = float[](
+		-1, -1, -1,
+		-1, 9, -1,
+		-1, -1, -1
+	);
 
-	return texsharp;
+	vec3 texsharp = vec3(0,0,0);
+	for (uint i = 0; i < 9; i++)
+		texsharp += texture(tex, uv + offsets[i]).rgb * sharp_kernel[i];
+			
+	return vec4(texsharp, 1);
 }
 
-vec3 sobel_filter(vec3 color)
+subroutine(shading_t)
+vec4 sobel_filter(vec4 color)
 {
 	float sobel_x[9] = float[](
 		-1, 0, 1,
@@ -81,42 +99,45 @@ vec3 sobel_filter(vec3 color)
 		vec_y += texture(tex, uv + offsets[i]).rgb * sobel_y[i];
 	}
 
-	return sqrt(vec_x * vec_x + vec_y * vec_y);
+	vec4 sobeled = vec4(sqrt(vec_x * vec_x + vec_y * vec_y), 1);	
+	return grayscale(sobeled);
 }
 
 void main()
 {
 	//rrra because depth textures are not usual textures, they have only one channel
-	final_color = (depth) ? texture(tex, uv).rrra : texture(tex, uv).rgba;
+	final_color = texture(tex, uv).rgba;		
 
-	if (depth) {
-	   float d;
-	   d = LinearizeDepth(uv);
-	   final_color = vec4(d,d,d,1.0);	   	   
-	}
-	else if (blur)
-	{	  
-	  final_color = vec4(blurring_func(uv), 1);
-	}
-	else if (sharpen)
-	{
-	  final_color = vec4(sharpening_func(uv));
-	}
-	else if (sepia)
-	{
-	final_color = vec4(final_color.r * .393 + final_color.g * .769 + final_color.b * .189,
-					   final_color.r * .349 + final_color.g * .686 + final_color.b * .168,
-					   final_color.r * .272 + final_color.g * .534 + final_color.b * .131, 1.0);
-	}
-	else if (grayscale)
-	{
-		float average = final_color.r * 0.2126 + final_color.g * 0.7152 + final_color.b * 0.0722;
-		final_color = vec4(average, average, average, 1.0);
-	}
-	else if (sobel)
-	{		
-		vec3 sobeled = sobel_filter(final_color.rgb);	
-		float average = sobeled.r * 0.2126 + sobeled.g * 0.7152 + sobeled.b * 0.0722;
-		final_color = vec4(average, average, average, 1.0);
-	}
+	final_color = Shading(final_color);
+
+//	if (depth) {
+//	   float d;
+//	   d = LinearizeDepth(uv);
+//	   final_color = vec4(d,d,d,1.0);	   	   
+//	}
+//	else if (blur)
+//	{	  
+//	  final_color = vec4(blurring_func(uv), 1);
+//	}
+//	else if (sharpen)
+//	{
+//	  final_color = vec4(sharpening_func(uv));
+//	}
+//	else if (sepia)
+//	{
+//	final_color = vec4(final_color.r * .393 + final_color.g * .769 + final_color.b * .189,
+//					   final_color.r * .349 + final_color.g * .686 + final_color.b * .168,
+//					   final_color.r * .272 + final_color.g * .534 + final_color.b * .131, 1.0);
+//	}
+//	else if (grayscale)
+//	{
+//		float average = final_color.r * 0.2126 + final_color.g * 0.7152 + final_color.b * 0.0722;
+//		final_color = vec4(average, average, average, 1.0);
+//	}
+//	else if (sobel)
+//	{		
+//		vec3 sobeled = sobel_filter(final_color.rgb);	
+//		float average = sobeled.r * 0.2126 + sobeled.g * 0.7152 + sobeled.b * 0.0722;
+//		final_color = vec4(average, average, average, 1.0);
+//	}
 }