framebuffer对象，麻烦渲染并将纹理传递给着色器

我试图渲染一个简单的场景到framebuffer，然后将其作为纹理传递给我的着色器。但是，我的渲染对象显示为黑色。我无法弄清楚我做错了什么。framebuffer对象，麻烦渲染并将纹理传递给着色器

在下面的代码中，我创建了一个FBO并为其添加了深度缓冲区和纹理。

GLuint fbo, fboDepth,fboTexture; 

// Create the texture 
glGenTexturesEXT(1, &fboTexture); 
glBindTextureEXT(GL_TEXTURE_2D, fboTexture); 
glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA8, 512, 512, 0, GL_RGBA, GL_FLOAT, NULL); 
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR); 
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR); 
glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR_MIPMAP_LINEAR); 
glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR_MIPMAP_LINEAR); 
// Create and bind an FBO 
glGenFramebuffersEXT(1, &fbo); 
glBindFramebufferEXT(GL_DRAW_FRAMEBUFFER_EXT, fbo); 

// Create depth renderbuffer 
glGenRenderbuffersEXT(1, &fboDepth); 
glBindRenderbufferEXT(GL_RENDERBUFFER_EXT, fboDepth); 
glRenderbufferStorageEXT(GL_RENDERBUFFER_EXT, GL_DEPTH_COMPONENT, 512, 512); 

glFramebufferTexture2D(GL_FRAMEBUFFER_EXT, GL_COLOR_ATTACHMENT0_EXT, GL_TEXTURE_2D, fboTexture, 0); 
glFramebufferRenderbuffer(GL_DRAW_FRAMEBUFFER_EXT, GL_DEPTH_ATTACHMENT_EXT, GL_RENDERBUFFER_EXT, fboDepth); 

GLenum fboStatus = glCheckFramebufferStatus(GL_DRAW_FRAMEBUFFER_EXT);         

if (fboStatus != GL_FRAMEBUFFER_COMPLETE) { 
    std::cout << "Couldn't create frame buffer" << std::endl;        
    exit(0);                     
} else { 
    cout << fbo << fboTexture << fboDepth << endl; 
} 

glBindFramebuffer(GL_DRAW_FRAMEBUFFER, 0); // Reset framebuffer binding

下面的代码是我的渲染方法。我用tga纹理尝试过，效果很好。

void Renderer::render(Geometry* geo) { 
glUseProgram(geo->shader->program); 

// Bind our frame buffer for rendering 
glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, fbo); 
glPushAttrib(GL_VIEWPORT_BIT | GL_ENABLE_BIT); 
glViewport(0, 0, 512, 512); 
glClear (GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT); 
    // render a triangle to the fbo 
glBegin(GL_TRIANGLES); 
glColor3f(1,0,0); 
glVertex2f(-1,0); 

glColor3f(0,1,0); 
glVertex2f(1,-1); 

glColor3f(0,0,1); 
glVertex2f(.5,.5); 
glEnd(); 

glPopAttrib(); 
glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, 0); 

GLuint texUniLoc = glGetUniformLocation(geo->shader->program, "Tex"); 

glActiveTexture(GL_TEXTURE0 + 1); 
glBindTextureEXT(GL_TEXTURE_2D, fboTexture); 
glUniform1i(texUniLoc, 1); 

GLuint vpm = glGetUniformLocation(geo->shader->program, "ViewProjectionMatrix"); 
glUniformMatrix4fv(vpm, 1, GL_TRUE, ViewProjectionMatrix.vec); 

float * m = (float*)malloc(sizeof(float)*16); 
m[0] = 1; m[1] = 0; m[2] = 0; m[3] = 0; 
m[4] = 0; m[5] = 1; m[6] = 0; m[7] = 0.0; 
m[8] = 0; m[9] = 0; m[10] = 1; m[11] = 0.0; 
m[12] = 0; m[13] = 0; m[14] = 0; m[15] = 1.0; 

    GLuint model = glGetUniformLocation(geo->shader->program, "ModelMatrix"); 
glUniformMatrix4fv(model, 1, GL_TRUE, m); 

// activate and specify pointer to vertex array 
glEnableClientState(GL_VERTEX_ARRAY); 
glEnableClientState(GL_INDEX_ARRAY); 
glEnableClientState(GL_TEXTURE_COORD_ARRAY); 

glVertexPointer(3, GL_FLOAT, 0, geo->vertices); 
glTexCoordPointer(2, GL_FLOAT, 0, geo->texcoords); 
glDrawElements(GL_TRIANGLES, 2*3*32*32, GL_UNSIGNED_SHORT, geo->indices); 

glDisableClientState(GL_VERTEX_ARRAY); 
glDisableClientState(GL_INDEX_ARRAY); 
glDisableClientState(GL_TEXTURE_COORD_ARRAY); 
glUseProgram(0); 
}

我试过.tga纹理和着色器效果很好。我正在使用glfw和glew。此外，我不确定glSomeFunction和glSomeFunctionEXT之间的区别

来源

2012-03-12 nyvaken

我不确定你为什么在这里使用malloc。这是分配内存的绝对*可怕的方式，并且在将它传递给glUniform后并不会删除分配的内存，因此您将在此处发生泄漏。为什么不只浮动m [16]？ – Robinson 2012-03-12 22:10:41

你是对的，这是非常临时的。 – nyvaken 2012-03-13 18:49:07

我修正了它。绘制三角形之前，我不应该调用glUseProgram。

来源

2012-03-13 18:51:54 nyvaken

framebuffer对象，麻烦渲染并将纹理传递给着色器

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