Hi!
I'am trying to render something to a texture using frame buffer objects. I set up a scene containing a cube with 3D texture coordinates which is processed using a pixel shader which maps the texture coordinates to the color (I will need this later) - works good when rendered to the window. I want to render it to a texture so I added a quad to the scene which will be textured (works with a texture loaded from a file). I bind the FBO before drawing the cube, then unbind it and try to render the quad textured with the texture attached to the FBO. But at best I get some random colours, but most of the time it's black. This is my code:
Initializing textures:
int current = 0;
GLuint TMP, DIR, RES, TEST[3];
GLuint Init2DTexture(GLenum internalFormat, GLsizei width, GLsizei height, GLenum format){//, int bytes){
GLuint texture;
//unsigned int* data;
//data = (unsigned int*) malloc(width * height * bytes * sizeof(unsigned int));
//ZeroMemory(data, (width * height * bytes * sizeof(unsigned int)));
glGenTextures(1, &texture); //jedna tekstura
glBindTexture(GL_TEXTURE_2D, texture);
glTexImage2D(GL_TEXTURE_2D, 0, internalFormat, width, height, 0, format, GL_UNSIGNED_BYTE, NULL);
//free(data);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
glBindTexture(GL_TEXTURE_2D, 0);
return texture;
}
GLuint Init2DTextureFromFile(char* name){
GLuint texture;
GLbyte *pBytes;
GLint nWidth, nHeight, nComponents;
GLenum format;
glGenTextures(1, &texture);
glBindTexture(GL_TEXTURE_2D, texture);
pBytes = gltLoadTGA(name, &nWidth, &nHeight, &nComponents, &format);
glTexImage2D(GL_TEXTURE_2D, 0, nComponents, nWidth, nHeight, 0, format, GL_UNSIGNED_BYTE, pBytes);
free(pBytes);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
glBindTexture(GL_TEXTURE_2D, 0);
return texture;
}
int InitTextures(void){
TMP = Init2DTexture(GL_RGBA8, 512, 512, GL_RGBA);
DIR = Init2DTexture(GL_RGB8, 512, 512, GL_RGB);
RES = Init2DTexture(GL_RGBA8, 512, 512, GL_RGBA);
TEST[0] = Init2DTextureFromFile("floor0.tga");
TEST[1] = Init2DTextureFromFile("floor1.tga");
TEST[2] = Init2DTextureFromFile("floor2.tga");
return TRUE;
}
Initializing FBO:
GLuint fb;
int InitFBOs(void){
GLuint depthBuffer;
GLenum status;
glGenFramebuffersEXT(1, &fb);
glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, fb);
glGenRenderbuffersEXT(1, &depthBuffer);
glBindRenderbufferEXT(GL_RENDERBUFFER_EXT, depthBuffer);
glRenderbufferStorageEXT(GL_RENDERBUFFER_EXT, GL_DEPTH_COMPONENT16, 512, 512);
glFramebufferRenderbufferEXT(GL_FRAMEBUFFER_EXT, GL_DEPTH_ATTACHMENT_EXT, GL_RENDERBUFFER_EXT, depthBuffer);
glFramebufferTexture2DEXT(GL_FRAMEBUFFER_EXT, GL_COLOR_ATTACHMENT0_EXT, GL_TEXTURE_2D, TMP, 0);
//status = glCheckFramebufferStatusEXT(GL_FRAMEBUFFER_EXT);
glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, 0);
return TRUE;
}
Rendering the scene:
int RenderScene(void){
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
glLoadIdentity();
glPushAttrib(GL_VIEWPORT_BIT);
glViewport(0, 0, 512, 512);
//Rendering to TMP
glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, fb);
glUseProgram(programs[PASS1]);
DrawCube();
glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, 0);
glPopAttrib();
glUseProgram(0);
//glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
glViewport(0, 0, window_w, window_h);
glEnable(GL_TEXTURE_2D);
//glBindTexture(GL_TEXTURE_2D, TEST[current]);
glBindTexture(GL_TEXTURE_2D, TMP);
DrawQuad();
glBindTexture(GL_TEXTURE_2D, 0);
glDisable(GL_TEXTURE_2D);
return TRUE;
}
Thanks in advance for any hint how to solve this problem.
