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Ticket Name: TDA2HG: [Opengl] -- the cube usage in fbo |
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Query Text: |
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Part Number: TDA2HG Other Parts Discussed in Thread: TDA2 hi: I have a question about the usage of cubemap in fbo; the simple code as bellow: { glGenFramebuffers(1, &fboID); glBindFramebuffer(GL_FRAMEBUFFER,fboID); glGenTextures(1, &cubemapID); glBindTexture(GL_TEXTURE_CUBE_MAP, cubemapID); for (unsigned int i = 0; i < 6; ++i) { glTexImage2D(GL_TEXTURE_CUBE_MAP_POSITIVE_X + i, 0, GL_RGB, 256, 256, 0, GL_RGB, GL_UNSIGNED_BYTE, nullptr); } glTexParameteri(GL_TEXTURE_CUBE_MAP, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE); glTexParameteri(GL_TEXTURE_CUBE_MAP, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE); glTexParameteri(GL_TEXTURE_CUBE_MAP, GL_TEXTURE_MIN_FILTER, GL_LINEAR); glTexParameteri(GL_TEXTURE_CUBE_MAP, GL_TEXTURE_MAG_FILTER, GL_LINEAR); glUniform.. //update the uniform variable glViewport(0, 0, 256, 256); for (unsigned int i = 0; i < 6; ++i) { glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_CUBE_MAP_POSITIVE_X + i, cubemapID, 0); if (glCheckFramebufferStatus(GL_FRAMEBUFFER) != GL_FRAMEBUFFER_COMPLETE) { printf("glCheckFramebufferStatus error!\n"); } glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT); renderCube(); } } when i test the code, it works well on windows, but when i move it to the tda2 platform, the question is comming, sometimes the effiect is black , or is white, or white and black , or other colors, it's change every time. how is this? and how to resolved it? thanks |
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Responses: |
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Hello, Can you try and see if this works: // Setup texture for cubemap
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glGenTextures(1, &textureCubeMap);
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char buffer0[CUBEMAP_TEX_LEN * CUBEMAP_TEX_LEN * 6];
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glBindTexture(GL_TEXTURE_CUBE_MAP, textureCubeMap);
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memset((void *)buffer0, 0x50, CUBEMAP_TEX_LEN*CUBEMAP_TEX_LEN*6);
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for(GLuint i = 0; i < 6; i++)
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{
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glTexImage2D(
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GL_TEXTURE_CUBE_MAP_POSITIVE_X + i,
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0, GL_RGBA8, CUBEMAP_TEX_LEN, CUBEMAP_TEX_LEN,
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0, GL_RGBA, GL_UNSIGNED_BYTE, (char *)buffer0
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);
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}
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glTexParameteri(GL_TEXTURE_CUBE_MAP, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
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glTexParameteri(GL_TEXTURE_CUBE_MAP, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
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glTexParameteri(GL_TEXTURE_CUBE_MAP, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
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glTexParameteri(GL_TEXTURE_CUBE_MAP, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
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glTexParameteri(GL_TEXTURE_CUBE_MAP, GL_TEXTURE_WRAP_R, GL_CLAMP_TO_EDGE);
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// Setup Framebuffer for cubemap
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glGenFramebuffers(1, &fbCubeMap);
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// Rendering part
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GLint current_fbo;
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glGetIntegerv(GL_FRAMEBUFFER_BINDING, ¤t_fbo);
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glBindFramebuffer(GL_FRAMEBUFFER, fbCubeMap);
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// Render to cubemap
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for (int i = 0; i < 6; i++)
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{
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glFramebufferTexture2D(GL_FRAMEBUFFER,
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GL_COLOR_ATTACHMENT0,
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GL_TEXTURE_CUBE_MAP_POSITIVE_X + i,
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textureCubeMap,
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0);
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glClear(GL_COLOR_BUFFER_BIT|GL_DEPTH_BUFFER_BIT);
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//.... draw/render to cube map surface
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}
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// Bind the original frame buffer
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glBindFramebuffer(GL_FRAMEBUFFER, current_fbo);
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// Use cubemap texture
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glBindTexture(GL_TEXTURE_CUBE_MAP, textureCubeMap);
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//... draw to the final framebuffer using cubemap
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// In the shader code, use samplerCube to sample texture
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// e.g:
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// uniform samplerCube skybox;
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// ...
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// vec4 colorval = texture(skybox, direction);
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If it still doesn't work, can you try and use glGetError to check for any errors? Regards Hemant |
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