多屏对比雾的density

main.cpp

@@ -72,7 +72,16 @@ INT WINAPI WinMain(_In_ HINSTANCE hInstance, _In_opt_ HINSTANCE hPrevInstance, _
 
 	glewInit();
 
-	//combine program
+	//init fsqgpu program
+	GPUProgram fsqProgram;
+	fsqProgram.AttachShader(GL_VERTEX_SHADER, "res/shader/fullscreenquad.vs");
+	fsqProgram.AttachShader(GL_FRAGMENT_SHADER, "res/shader/fullscreenquad.fs");
+	fsqProgram.Link();
+	fsqProgram.DetectAttribute("pos");
+	fsqProgram.DetectAttribute("texcoord");
+	fsqProgram.DetectUniform("U_MainTexture");
+
+	//gpu program
 	GPUProgram gpuProgram;
 	gpuProgram.AttachShader(GL_VERTEX_SHADER, "res/shader/forg.vs");
 	gpuProgram.AttachShader(GL_FRAGMENT_SHADER, "res/shader/forg.fs");
@@ -140,16 +149,26 @@ INT WINAPI WinMain(_In_ HINSTANCE hInstance, _In_opt_ HINSTANCE hPrevInstance, _
 
 	glm::mat4 cubeModelMatrix3 = glm::translate<float>(-0.4f, 0.0f, -20.0f) * glm::rotate(-30.0f, 1.0f, 1.0f, 1.0f);
 	glm::mat4 cubeNormalMatrix3 = glm::inverseTranspose(cubeModelMatrix);
-
-
 	//glm::mat4 viewMatrix = glm::lookAt(glm::vec3(1.0f, 0.5f, -10.0f), glm::vec3(0.0f, 0.0f, -1.0f), glm::vec3(0.0f, 1.0f, 0.0f));
 	glm::mat4 projectionMatrix = glm::perspective(50.0f, (float)viewportWidth / (float)viewportHeight, 0.1f, 1000.0f);
 	
+	//³õʼ»¯fsq
+	FullScreenQuad fsq;
+	fsq.Init();
+
+	//³õʼ»¯2¸öfbo
+	FBO fbo[2];
+	fbo[0].AttachColorBuffer("color", GL_COLOR_ATTACHMENT0, GL_RGBA, viewportWidth, viewportHeight);
+	fbo[0].AttachDepthBuffer("depth", viewportWidth, viewportHeight);
+	fbo[0].Finish();
+	fbo[1].AttachColorBuffer("color", GL_COLOR_ATTACHMENT0, GL_RGBA, viewportWidth, viewportHeight);
+	fbo[1].AttachDepthBuffer("depth", viewportWidth, viewportHeight);
+	fbo[1].Finish();
 
 	ShowWindow(hwnd, SW_SHOW);
 	UpdateWindow(hwnd);
 
-	glClearColor(0.6f, 0.6f, 0.6f, 1.0f);
+	glClearColor(0.0f, 0.0f, 0.0f, 1.0f);
 	MSG msg;
 	while (true)
 	{
@@ -163,7 +182,6 @@ INT WINAPI WinMain(_In_ HINSTANCE hInstance, _In_opt_ HINSTANCE hPrevInstance, _
 			DispatchMessage(&msg);
 		}
 		glEnable(GL_DEPTH_TEST);
-		glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
 		glUseProgram(gpuProgram.mProgram);
 
 		
@@ -184,25 +202,64 @@ INT WINAPI WinMain(_In_ HINSTANCE hInstance, _In_opt_ HINSTANCE hPrevInstance, _
 		glUniform1f(gpuProgram.GetLocation("U_FogStart"), fogStart);
 		glUniform1f(gpuProgram.GetLocation("U_FogEnd"), fogEnd);
 		glUniform4fv(gpuProgram.GetLocation("U_FogColor"), 1, fogColor);
-		glUniform1f(gpuProgram.GetLocation("U_FogDensity"), fogDensity);
 
+
+		fbo[0].Bind();
+		fogDensity = 0.11;
+		glUniform1f(gpuProgram.GetLocation("U_FogDensity"), fogDensity);
+		glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
 		glUniformMatrix4fv(gpuProgram.GetLocation("M"), 1, GL_FALSE, glm::value_ptr(cubeModelMatrix));
 		glUniformMatrix4fv(gpuProgram.GetLocation("NM"), 1, GL_FALSE, glm::value_ptr(cubeNormalMatrix));
 		cube.Bind(gpuProgram.GetLocation("pos"), gpuProgram.GetLocation("texcoord"), gpuProgram.GetLocation("normal"));
 		cube.Draw();
-
 		glUniformMatrix4fv(gpuProgram.GetLocation("M"), 1, GL_FALSE, glm::value_ptr(cubeModelMatrix2));
 		glUniformMatrix4fv(gpuProgram.GetLocation("NM"), 1, GL_FALSE, glm::value_ptr(cubeNormalMatrix2));
 		cube.Bind(gpuProgram.GetLocation("pos"), gpuProgram.GetLocation("texcoord"), gpuProgram.GetLocation("normal"));
 		cube.Draw();
+		glUniformMatrix4fv(gpuProgram.GetLocation("M"), 1, GL_FALSE, glm::value_ptr(cubeModelMatrix3));
+		glUniformMatrix4fv(gpuProgram.GetLocation("NM"), 1, GL_FALSE, glm::value_ptr(cubeNormalMatrix3));
+		cube.Bind(gpuProgram.GetLocation("pos"), gpuProgram.GetLocation("texcoord"), gpuProgram.GetLocation("normal"));
+		cube.Draw();
+		fbo[0].Unbind();
 
-
+		fbo[1].Bind();
+		fogDensity = 0.31;
+		glUniform1f(gpuProgram.GetLocation("U_FogDensity"), fogDensity);
+		glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
+		glUniformMatrix4fv(gpuProgram.GetLocation("M"), 1, GL_FALSE, glm::value_ptr(cubeModelMatrix));
+		glUniformMatrix4fv(gpuProgram.GetLocation("NM"), 1, GL_FALSE, glm::value_ptr(cubeNormalMatrix));
+		cube.Bind(gpuProgram.GetLocation("pos"), gpuProgram.GetLocation("texcoord"), gpuProgram.GetLocation("normal"));
+		cube.Draw();
+		glUniformMatrix4fv(gpuProgram.GetLocation("M"), 1, GL_FALSE, glm::value_ptr(cubeModelMatrix2));
+		glUniformMatrix4fv(gpuProgram.GetLocation("NM"), 1, GL_FALSE, glm::value_ptr(cubeNormalMatrix2));
+		cube.Bind(gpuProgram.GetLocation("pos"), gpuProgram.GetLocation("texcoord"), gpuProgram.GetLocation("normal"));
+		cube.Draw();
 		glUniformMatrix4fv(gpuProgram.GetLocation("M"), 1, GL_FALSE, glm::value_ptr(cubeModelMatrix3));
 		glUniformMatrix4fv(gpuProgram.GetLocation("NM"), 1, GL_FALSE, glm::value_ptr(cubeNormalMatrix3));
 		cube.Bind(gpuProgram.GetLocation("pos"), gpuProgram.GetLocation("texcoord"), gpuProgram.GetLocation("normal"));
 		cube.Draw();
+		fbo[1].Unbind();
 		glUseProgram(0);
 		glFlush();
+
+
+		
+		glClearColor(0.6f, 0.6f, 0.6f, 1.0f);
+		glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
+		glActiveTexture(GL_TEXTURE0);
+		
+		glUseProgram(fsqProgram.mProgram);
+		glBindTexture(GL_TEXTURE_2D, fbo[0].GetBuffer("color"));
+		glUniform1i(fsqProgram.GetLocation("U_MainTexture"), 0);
+		fsq.DrawToLeftTop(fsqProgram.GetLocation("pos"), fsqProgram.GetLocation("texcoord"));
+
+		glBindTexture(GL_TEXTURE_2D, fbo[1].GetBuffer("color"));
+		glUniform1i(fsqProgram.GetLocation("U_MainTexture"), 0);
+		fsq.DrawToRightTop(fsqProgram.GetLocation("pos"), fsqProgram.GetLocation("texcoord"));
+
+		glUseProgram(0);
+
+		
 		SwapBuffers(dc);
 	}
 	return 0;