Native mosaic PGE fragment shader implementation. Co-authored-by: sigonasr2 <sigonasr2@gmail.com>

main.cpp

@@ -37,12 +37,17 @@ public:
 		}else{
 			lastIncrease=std::max(0.f,lastIncrease-fElapsedTime);
 		}
-		Clear(WHITE);
+		Clear(BLACK);
 		srand(48190);
-		for(int i=0;i<100;i++){
+		for(int i=0;i<500;i++){
+			if(rand()%2){
 				DrawCircle({rand()%640,rand()%480},rand()%30,{uint8_t(rand()%255),uint8_t(rand()%255),uint8_t(rand()%255)});
+			}else{
+				FillCircle({rand()%640,rand()%480},rand()%30,{uint8_t(rand()%255),uint8_t(rand()%255),uint8_t(rand()%255)});
+			}
 		}
-		DrawStringDecal({0,0},"Mosaic Effect: "+std::to_string(GetMosaicEffect()),BLACK);
+		DrawStringDecal({1,1},"Mosaic Effect: "+std::to_string(GetMosaicEffect()),BLACK);
+		DrawStringDecal({0,0},"Mosaic Effect: "+std::to_string(GetMosaicEffect()),WHITE);
 		return true;
 	}
 

pixelGameEngine.h

@@ -1248,7 +1248,7 @@ namespace olc
 		std::vector<std::string> vDroppedFilesCache;
 		olc::vi2d vDroppedFilesPoint;
 		olc::vi2d vDroppedFilesPointCache;
-		uint8_t mosaic=0;
+		uint8_t mosaic=1;
 
 		// Command Console Specific
 		bool bConsoleShow = false;
@@ -3596,7 +3596,7 @@ namespace olc
 		return mosaic;
 	}
 	void PixelGameEngine::SetMosaicEffect(uint8_t effectLevel){
-		mosaic=effectLevel;
+		mosaic=std::max(uint8_t(1),effectLevel);
 	}
 
 
@@ -4865,8 +4865,17 @@ namespace olc
 #else
 				"#version 330 core\n"
 #endif
-				"out vec4 pixel;\n""in vec2 oTex;\n"
-				"in vec4 oCol;\n""uniform sampler2D sprTex;\n""void main(){pixel = texture(sprTex, oTex) * oCol;}";
+				"out vec4 pixel;\n"
+				"in vec2 oTex;\n"
+				"in vec4 oCol;\n"
+				"uniform int mosaic;\n"
+				"uniform vec2 size;\n"
+				"uniform sampler2D sprTex;\n"
+				"void main(){\n"
+					"vec2 texelSize = 1.0 / size; \n"
+					"vec2 pos = oTex / texelSize; \n""vec2 outputPos = vec2(floor(pos.x/float(mosaic))*float(mosaic),floor(pos.y/float(mosaic))*float(mosaic));\n"
+					"pixel = texture(sprTex, outputPos*texelSize) * oCol;\n"
+				"}";
 			locShaderSource(m_nFS, 1, &strFS, NULL);
 			locCompileShader(m_nFS);
 
@@ -4883,13 +4892,12 @@ namespace olc
 				"layout(location = 2) in vec4 aCol;\n"
 				"out vec2 oTex;\n"
 				"out vec4 oCol;\n"
-				"uniform int mosaic;\n"
 				"\n"
 				"void main(){\n"
 					"float p = 1.0 / aPos.z;\n"
 					"gl_Position = p * vec4(aPos.x, aPos.y, 0.0, 1.0);\n"
 					"oTex = p * aTex;\n"
-					"oCol = vec4(aCol.r,float(mosaic)/255.0,0,aCol.a);\n"
+					"oCol = aCol;\n"
 				"}";
 			locShaderSource(m_nVS, 1, &strVS, NULL);
 			locCompileShader(m_nVS);
@@ -4974,7 +4982,9 @@ namespace olc
 			glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
 			locUseProgram(m_nQuadShader);
 			GLint myUniformLocation = glGetUniformLocation(m_nQuadShader, "mosaic");
+			GLint myUniformLocation2 = glGetUniformLocation(m_nQuadShader, "size");
 			glUniform1i(myUniformLocation,ptrPGE->GetMosaicEffect());
+			glUniform2f(myUniformLocation2,ptrPGE->ScreenWidth(),ptrPGE->ScreenHeight());
 			locBindVertexArray(m_vaQuad);
 
 #if defined(OLC_PLATFORM_EMSCRIPTEN)