framebuffer 类封装

framebufferobject.cpp

@@ -0,0 +1,79 @@
+#include "framebufferobject.h"
+
+FrameBufferObject::FrameBufferObject()
+{
+	glGenFramebuffers(1, &mFrameBufferObject);
+}
+
+void FrameBufferObject::AttachColorBuffer(const char * bufferName, GLenum attachment, int width, int height)
+{
+	GLuint colorBuffer;
+	glBindFramebuffer(GL_FRAMEBUFFER, mFrameBufferObject);
+	glGenTextures(1, &colorBuffer);
+	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);
+	glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, 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));
+	glBindFramebuffer(GL_FRAMEBUFFER, 0);
+}
+
+void FrameBufferObject::AttachDepthBuffer(const char * bufferName, int width, int height)
+{
+	GLuint depthMap;
+	glBindFramebuffer(GL_FRAMEBUFFER, mFrameBufferObject);
+	glGenTextures(1, &depthMap);
+	glBindTexture(GL_TEXTURE_2D, depthMap);
+	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
+	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
+	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
+	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
+	glTexImage2D(GL_TEXTURE_2D, 0, GL_DEPTH_COMPONENT, width, height, 0, GL_DEPTH_COMPONENT, depthMap, 0);
+	glBindTexture(GL_TEXTURE_2D, 0);
+	glFramebufferTexture2D(GL_FRAMEBUFFER, GL_DEPTH_ATTACHMENT, GL_TEXTURE_2D, depthMap, 0);
+	mBuffers.insert(std::pair<std::string, GLuint>(bufferName, depthMap));
+	glBindFramebuffer(GL_FRAMEBUFFER, 0);
+}
+
+void FrameBufferObject::Finish()
+{
+	int nCount = (int)mDrawBuffers.size();
+	if (nCount > 0) {
+		GLenum *buffers = new GLenum[nCount];
+		int i = 0;
+		while (i < nCount) {
+			buffers[i] = mDrawBuffers[i];
+			i++;
+		}
+		glBindFramebuffer(GL_FRAMEBUFFER, mFrameBufferObject);
+		glDrawBuffers(nCount, buffers);
+		glBindFramebuffer(GL_FRAMEBUFFER, 0);
+	}
+}
+
+void FrameBufferObject::Bind()
+{
+	glGetIntegerv(GL_FRAMEBUFFER_BINDING, &mPrevFrameBuffer);
+	glBindFramebuffer(GL_FRAMEBUFFER, mFrameBufferObject);
+	glClearColor(0.0f, 0.0f, 0.0f, 0.0f);
+	glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
+}
+
+void FrameBufferObject::Unbind()
+{
+	glBindFramebuffer(GL_FRAMEBUFFER, mPrevFrameBuffer);
+}
+
+GLuint FrameBufferObject::GetBuffer(const char * bufferName)
+{
+	auto iter = mBuffers.find(bufferName);
+	if (iter != mBuffers.end()) {
+		return iter->second;
+	}
+	return 0;
+}
+
+

framebufferobject.h

@@ -0,0 +1,17 @@
+#pragma once
+#include "ggl.h"
+class FrameBufferObject {
+public:
+	GLuint mFrameBufferObject;
+	GLint mPrevFrameBuffer;
+	std::map<std::string, GLuint> mBuffers;
+	std::vector<GLenum> mDrawBuffers;
+public:
+	FrameBufferObject();
+	void AttachColorBuffer(const char* bufferName, GLenum attachment, int width, int height);
+	void AttachDepthBuffer(const char* bufferName, int width, int height);
+	void Finish();
+	void Bind();
+	void Unbind();
+	GLuint GetBuffer(const char* bufferName);
+};

renderFramework.vcxproj

@@ -126,6 +126,7 @@
     </Link>
   </ItemDefinitionGroup>
   <ItemGroup>
+    <ClCompile Include="framebufferobject.cpp" />
     <ClCompile Include="main.cpp" />
     <ClCompile Include="model.cpp" />
     <ClCompile Include="scene.cpp" />
@@ -134,6 +135,7 @@
     <ClCompile Include="vertexbuffer.cpp" />
   </ItemGroup>
   <ItemGroup>
+    <ClInclude Include="framebufferobject.h" />
     <ClInclude Include="ggl.h" />
     <ClInclude Include="model.h" />
     <ClInclude Include="scene.h" />

renderFramework.vcxproj.filters

@@ -33,6 +33,9 @@
     <ClCompile Include="model.cpp">
       <Filter>源文件</Filter>
     </ClCompile>
+    <ClCompile Include="framebufferobject.cpp">
+      <Filter>源文件</Filter>
+    </ClCompile>
   </ItemGroup>
   <ItemGroup>
     <ClInclude Include="ggl.h">
@@ -53,5 +56,8 @@
     <ClInclude Include="model.h">
       <Filter>源文件</Filter>
     </ClInclude>
+    <ClInclude Include="framebufferobject.h">
+      <Filter>源文件</Filter>
+    </ClInclude>
   </ItemGroup>
 </Project>