通过depth buffer得到阴影图

FBO.cpp

@@ -13,18 +13,19 @@ void FBO::AttachColorBuffer(const char*bufferName, GLenum attachment, GLenum dat
 	glBindTexture(GL_TEXTURE_2D, colorBuffer);
 	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
 	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
-
-	if (dataType == GL_RGBA16F) {
+	if (dataType == GL_RGBA16F)
+	{
 		glTexImage2D(GL_TEXTURE_2D, 0, dataType, width, height, 0, GL_RGBA, GL_UNSIGNED_SHORT, NULL);
 	}
-	else {
+	else
+	{
 		glTexImage2D(GL_TEXTURE_2D, 0, dataType, width, height, 0, GL_RGBA, GL_UNSIGNED_BYTE, NULL);
 	}
 	glBindTexture(GL_TEXTURE_2D, 0);
 	glFramebufferTexture2D(GL_FRAMEBUFFER, attachment, GL_TEXTURE_2D, colorBuffer, 0);
-	
+
 	mDrawBuffers.push_back(attachment);
-	mBuffers.insert(std::pair<std::string,GLuint>(bufferName,colorBuffer));
+	mBuffers.insert(std::pair<std::string, GLuint>(bufferName, colorBuffer));
 	glBindFramebuffer(GL_FRAMEBUFFER, 0);
 }
 
@@ -52,7 +53,7 @@ void FBO::Finish()
 	{
 		GLenum *buffers = new GLenum[nCount];
 		int i = 0;
-		while (i < nCount)
+		while (i<nCount)
 		{
 			buffers[i++] = mDrawBuffers[i];
 		}
@@ -75,7 +76,7 @@ void FBO::Unbind()
 GLuint FBO::GetBuffer(const char*bufferName)
 {
 	auto iter = mBuffers.find(bufferName);
-	if (iter!=mBuffers.end())
+	if (iter != mBuffers.end())
 	{
 		return iter->second;
 	}

FBO.h

@@ -12,7 +12,7 @@ public:
 public:
 	FBO();
 	//hdr/normal color
-	void AttachColorBuffer(const char*bufferName,GLenum attachment,GLenum dataType,int width,int height);
+	void AttachColorBuffer(const char*bufferName, GLenum attachment, GLenum dataType, int width, int height);
 	void AttachDepthBuffer(const char*bufferName, int width, int height);
 	//complete fbo settings
 	void Finish();

main.cpp

@@ -81,6 +81,15 @@ INT WINAPI WinMain(_In_ HINSTANCE hInstance, _In_opt_ HINSTANCE hPrevInstance, _
 	originalProgram.DetectAttribute("texcoord");
 	originalProgram.DetectUniform("U_MainTexture");
 
+	//init depth render program
+	GPUProgram depthRenderProgram;
+	depthRenderProgram.AttachShader(GL_VERTEX_SHADER, "res/shader/fullscreenquad.vs");
+	depthRenderProgram.AttachShader(GL_FRAGMENT_SHADER, "res/shader/depthrender.fs");
+	depthRenderProgram.Link();
+	depthRenderProgram.DetectAttribute("pos");
+	depthRenderProgram.DetectAttribute("texcoord");
+	depthRenderProgram.DetectUniform("U_MainTexture");
+
 	//init hdr program
 	GPUProgram hdrProgram;
 	hdrProgram.AttachShader(GL_VERTEX_SHADER, "res/shader/fullscreenquad.vs");
@@ -120,6 +129,16 @@ INT WINAPI WinMain(_In_ HINSTANCE hInstance, _In_opt_ HINSTANCE hPrevInstance, _
 	lightSourceProgram.DetectUniform("V");
 	lightSourceProgram.DetectUniform("P");
 
+	//init depth program
+	GPUProgram depthProgram;
+	depthProgram.AttachShader(GL_VERTEX_SHADER, "res/shader/sample_depth_buffer.vs");
+	depthProgram.AttachShader(GL_FRAGMENT_SHADER, "res/shader/sample_depth_buffer.fs");
+	depthProgram.Link();
+	depthProgram.DetectAttribute("pos");
+	depthProgram.DetectUniform("M");
+	depthProgram.DetectUniform("V");
+	depthProgram.DetectUniform("P");
+
 
 	//init gpu program
 	GPUProgram gpuProgram;
@@ -188,6 +207,8 @@ INT WINAPI WinMain(_In_ HINSTANCE hInstance, _In_opt_ HINSTANCE hPrevInstance, _
 	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, 800.0f / 600.0f, 0.1f, 1000.0f);
 
+	glm::mat4 lightMatrix = glm::lookAt(glm::vec3(0.0f, 10.0f, 0.0f), glm::vec3(0.0f, 0.0f, -2.0f), glm::vec3(0.0f, 0.0f, -1.0f));
+	glm::mat4 lightprojectionMatrix = glm::ortho(-5.0f, 5.0f, -5.0f, 5.0f, 0.1f, 15.0f);
 
 	//³õʼ»¯fsq
 	FullScreenQuad fsq;
@@ -208,10 +229,34 @@ INT WINAPI WinMain(_In_ HINSTANCE hInstance, _In_opt_ HINSTANCE hPrevInstance, _
 	HDRfbo.AttachDepthBuffer("depth", viewportWidth, viewportHeight);
 	HDRfbo.Finish();
 
+	FBO depthfbo;
+	depthfbo.AttachColorBuffer("color", GL_COLOR_ATTACHMENT0, GL_RGB, viewportWidth, viewportHeight);
+	depthfbo.AttachDepthBuffer("depth", viewportWidth, viewportHeight);
+	depthfbo.Finish();
+
 	ShowWindow(hwnd, SW_SHOW);
 	UpdateWindow(hwnd);
 
-	glClearColor(0.0f, 0.0f, 0.0f, 1.0f);
+	glClearColor(0.1f, 0.1f, 0.1f, 1.0f);
+	glEnable(GL_DEPTH_TEST);
+
+	depthfbo.Bind();
+	glUseProgram(depthProgram.mProgram);
+	glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
+	glUniformMatrix4fv(depthProgram.GetLocation("M"), 1, GL_FALSE, glm::value_ptr(model));
+	glUniformMatrix4fv(depthProgram.GetLocation("V"), 1, GL_FALSE, glm::value_ptr(lightMatrix));
+	glUniformMatrix4fv(depthProgram.GetLocation("P"), 1, GL_FALSE, glm::value_ptr(lightprojectionMatrix));
+	obj.Bind(depthProgram.GetLocation("pos"), depthProgram.GetLocation("texcoord"), depthProgram.GetLocation("normal"));
+	obj.Draw();
+
+	glUniformMatrix4fv(depthProgram.GetLocation("M"), 1, GL_FALSE, glm::value_ptr(quadModel));
+	quad.Bind(depthProgram.GetLocation("pos"), depthProgram.GetLocation("texcoord"), depthProgram.GetLocation("normal"));
+	quad.Draw();
+
+	glUseProgram(0);
+	depthfbo.Unbind();
+
+
 	MSG msg;
 	while (true)
 	{
@@ -224,7 +269,6 @@ INT WINAPI WinMain(_In_ HINSTANCE hInstance, _In_opt_ HINSTANCE hPrevInstance, _
 			TranslateMessage(&msg);
 			DispatchMessage(&msg);
 		}
-		glEnable(GL_DEPTH_TEST);
 
 
 		HDRfbo.Bind();
@@ -311,10 +355,10 @@ INT WINAPI WinMain(_In_ HINSTANCE hInstance, _In_opt_ HINSTANCE hPrevInstance, _
 		glUniform1i(originalProgram.GetLocation("U_MainTexture"), 0);
 		fsq.DrawToLeftTop(originalProgram.GetLocation("pos"), originalProgram.GetLocation("texcoord"));
 
-		glUseProgram(hdrProgram.mProgram);
-		glBindTexture(GL_TEXTURE_2D, HDRfbo.GetBuffer("hdrcolor"));
-		glUniform1i(hdrProgram.GetLocation("U_MainTexture"), 0);
-		fsq.DrawToRightTop(hdrProgram.GetLocation("pos"), hdrProgram.GetLocation("texcoord"));
+		glUseProgram(depthRenderProgram.mProgram);
+		glBindTexture(GL_TEXTURE_2D, depthfbo.GetBuffer("depth"));
+		glUniform1i(depthRenderProgram.GetLocation("U_MainTexture"), 0);
+		fsq.DrawToRightTop(depthRenderProgram.GetLocation("pos"), depthRenderProgram.GetLocation("texcoord"));
 
 		glUseProgram(gaussianProgram.mProgram);
 		glBindTexture(GL_TEXTURE_2D, fbo[1].GetBuffer("color"));

res/shader/depthrender.fs

@@ -0,0 +1,11 @@
+
+varying vec2 V_Texcoord;
+
+uniform sampler2D U_MainTexture;
+
+void main()
+{
+	float depthValue=texture2D(U_MainTexture,V_Texcoord).r;
+	depthValue = pow(depthValue, 2);
+	gl_FragColor=vec4(vec3(depthValue),1.0);
+}

res/shader/sample_depth_buffer.fs

@@ -0,0 +1,4 @@
+
+void main()
+{
+}

res/shader/sample_depth_buffer.vs

@@ -0,0 +1,12 @@
+attribute vec3 pos;
+attribute vec2 texcoord;
+attribute vec3 normal;
+
+uniform mat4 M;
+uniform mat4 P;
+uniform mat4 V;
+
+void main()
+{
+	gl_Position=P*V*M*vec4(pos,1.0);
+}

shader3.vcxproj

@@ -82,7 +82,11 @@
     <ClInclude Include="utils.h" />
   </ItemGroup>
   <ItemGroup>
+    <None Include="res\shader\depthrender.fs" />
+    <None Include="res\shader\fullscreenquad.vs" />
     <None Include="res\shader\hdr.fs" />
+    <None Include="res\shader\sample_depth_buffer.fs" />
+    <None Include="res\shader\sample_depth_buffer.vs" />
   </ItemGroup>
   <Import Project="$(VCTargetsPath)\Microsoft.Cpp.targets" />
   <ImportGroup Label="ExtensionTargets">

shader3.vcxproj.filters

@@ -49,5 +49,17 @@
     <None Include="res\shader\hdr.fs">
       <Filter>src</Filter>
     </None>
+    <None Include="res\shader\sample_depth_buffer.fs">
+      <Filter>src</Filter>
+    </None>
+    <None Include="res\shader\sample_depth_buffer.vs">
+      <Filter>src</Filter>
+    </None>
+    <None Include="res\shader\depthrender.fs">
+      <Filter>src</Filter>
+    </None>
+    <None Include="res\shader\fullscreenquad.vs">
+      <Filter>src</Filter>
+    </None>
   </ItemGroup>
 </Project>