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POHow do you render multiple VBO/IBOs?
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  1. POHow do you render multiple VBO/IBOs?
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    copied!<p>Here is what I am currently trying...</p> <p>Variable initialization:</p> <pre><code>GLuint vertexbuffer; GLuint uvbuffer; GLuint normalbuffer; GLuint colorbuffer; GLuint elementbuffer; GLuint VertexArrayID; std::vector&lt;unsigned short&gt; indices; std::vector&lt;glm::vec3&gt; indexed_vertices; std::vector&lt;glm::vec2&gt; indexed_uvs; std::vector&lt;glm::vec3&gt; indexed_normals; std::vector&lt;glm::vec4&gt; indexed_colors; GLuint vertexbuffer2; GLuint uvbuffer2; GLuint normalbuffer2; GLuint colorbuffer2; GLuint elementbuffer2; GLuint VertexArrayID2; std::vector&lt;unsigned short&gt; indices2; std::vector&lt;glm::vec3&gt; indexed_vertices2; std::vector&lt;glm::vec2&gt; indexed_uvs2; std::vector&lt;glm::vec3&gt; indexed_normals2; std::vector&lt;glm::vec4&gt; indexed_colors2; struct PackedVertex{ glm::vec3 position; glm::vec2 uv; glm::vec3 normal; glm::vec4 color; bool operator&lt;(const PackedVertex that) const{ return memcmp((void*)this, (void*)&amp;that, sizeof(PackedVertex))&gt;0; }; }; std::vector&lt;glm::vec3&gt; in_vertices; std::vector&lt;glm::vec2&gt; in_uvs; std::vector&lt;glm::vec3&gt; in_normals; std::vector&lt;glm::vec4&gt; in_colors; in_vertices.push_back(glm::vec3(0,0,0)); in_vertices.push_back(glm::vec3(1,0,0)); in_uvs.push_back(glm::vec2(0,0)); in_uvs.push_back(glm::vec2(0,0)); in_normals.push_back(glm::vec3(0,1,0)); in_normals.push_back(glm::vec3(0,1,0)); in_colors.push_back(glm::vec4(1,1,1,1)); in_colors.push_back(glm::vec4(1,0,0,1)); std::vector&lt;glm::vec3&gt; in_vertices2; std::vector&lt;glm::vec2&gt; in_uvs2; std::vector&lt;glm::vec3&gt; in_normals2; std::vector&lt;glm::vec4&gt; in_colors2; in_vertices2.push_back(glm::vec3(0,1.3,0)); in_vertices2.push_back(glm::vec3(1,1.3,0)); in_uvs2.push_back(glm::vec2(0,0)); in_uvs2.push_back(glm::vec2(0,0)); in_normals2.push_back(glm::vec3(0,1,0)); in_normals.push_back(glm::vec3(0,1,0)); in_colors2.push_back(glm::vec4(0,0,1,1)); in_colors2.push_back(glm::vec4(0,0,1,1)); </code></pre> <p>Intit the buffers:</p> <pre><code>void InitializeVertexBuffer(GLuint &amp;theBuffer, GLenum target, GLenum usage, const void* data, int size) { glGenBuffers(1, &amp;theBuffer); glBindBuffer(target, theBuffer); glBufferData(target, size, data, usage); glBindBuffer(target, 0); } </code></pre> <p>Setting up IBO/VAO/VBO:</p> <pre><code>// For each input vertex for ( unsigned int i=0; i&lt;2; i++ ){ // Try to find a similar vertex in out_XXXX unsigned short index; bool found = getSimilarVertexIndex(in_vertices[i], in_uvs[i], in_normals[i], indexed_vertices, indexed_uvs, indexed_normals, index); if ( found ){ // A similar vertex is already in the VBO, use it instead ! indices.push_back( index ); }else{ // If not, it needs to be added in the output data. indexed_vertices.push_back( in_vertices[i]); indexed_uvs .push_back( in_uvs[i]); indexed_normals .push_back( in_normals[i]); indexed_colors .push_back( in_colors[i]); indices .push_back( (unsigned short)indexed_vertices.size() - 1 ); } } size_t colorDataOffset = 0; InitializeVertexBuffer(vertexbuffer, GL_ARRAY_BUFFER, GL_STATIC_DRAW, &amp;indexed_vertices[0], indexed_vertices.size() * sizeof(glm::vec3) ); InitializeVertexBuffer(uvbuffer, GL_ARRAY_BUFFER, GL_STATIC_DRAW, &amp;indexed_vertices[0], indexed_vertices.size() * sizeof(glm::vec2) ); InitializeVertexBuffer(normalbuffer, GL_ARRAY_BUFFER, GL_STATIC_DRAW, &amp;indexed_normals[0], indexed_normals.size() * sizeof(glm::vec3) ); InitializeVertexBuffer(colorbuffer, GL_ARRAY_BUFFER, GL_STATIC_DRAW, &amp;indexed_colors[0], indexed_colors.size() * sizeof(glm::vec4) ); InitializeVertexBuffer(elementbuffer, GL_ARRAY_BUFFER, GL_STATIC_DRAW, &amp;indices[0], indices.size() * sizeof(unsigned short) ); //Generate VAO glGenVertexArrays(1, &amp;VertexArrayID); glBindVertexArray(VertexArrayID); // 1rst attribute buffer : vertices glEnableVertexAttribArray(0); glBindBuffer(GL_ARRAY_BUFFER, vertexbuffer); glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 0, (void*)0 ); // 2nd attribute buffer : normals glEnableVertexAttribArray(1); glBindBuffer(GL_ARRAY_BUFFER, normalbuffer); glVertexAttribPointer(1, 3, GL_FLOAT, GL_FALSE, 0, (void*)0 ); // 3nd attribute buffer : UVs glEnableVertexAttribArray(2); glBindBuffer(GL_ARRAY_BUFFER, uvbuffer); glVertexAttribPointer(2, 2, GL_FLOAT, GL_FALSE, 0, (void*)0 ); // 4th attribute buffer : colors glEnableVertexAttribArray(3); glBindBuffer(GL_ARRAY_BUFFER, colorbuffer); glVertexAttribPointer(3, 4, GL_FLOAT, GL_FALSE, 0, (void*)0 ); // Index buffer glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, elementbuffer); //****Second one*****// // For each input vertex for ( unsigned int i=0; i&lt;2; i++ ){ // Try to find a similar vertex in out_XXXX unsigned short index; bool found = getSimilarVertexIndex(in_vertices2[i], in_uvs2[i], in_normals2[i], indexed_vertices2, indexed_uvs2, indexed_normals2, index); if ( found ){ // A similar vertex is already in the VBO, use it instead ! indices2.push_back( index ); }else{ // If not, it needs to be added in the output data. indexed_vertices2.push_back( in_vertices2[i]); indexed_uvs2 .push_back( in_uvs2[i]); indexed_normals2 .push_back( in_normals[i]); indexed_colors2 .push_back( in_colors2[i]); indices2.push_back( (unsigned short)indexed_vertices2.size() - 1 ); } } size_t colorDataOffset = 0; InitializeVertexBuffer(vertexbuffer2, GL_ARRAY_BUFFER, GL_STATIC_DRAW, &amp;indexed_vertices2[0], indexed_vertices2.size() * sizeof(glm::vec3) ); InitializeVertexBuffer(uvbuffer2, GL_ARRAY_BUFFER, GL_STATIC_DRAW, &amp;indexed_vertices2[0], indexed_vertices2.size() * sizeof(glm::vec2) ); InitializeVertexBuffer(normalbuffer2, GL_ARRAY_BUFFER, GL_STATIC_DRAW, &amp;indexed_normals2[0], indexed_normals2.size() * sizeof(glm::vec3) ); InitializeVertexBuffer(colorbuffer2, GL_ARRAY_BUFFER, GL_STATIC_DRAW, &amp;indexed_colors2[0], indexed_colors2.size() * sizeof(glm::vec4) ); InitializeVertexBuffer(elementbuffer2, GL_ARRAY_BUFFER, GL_STATIC_DRAW, &amp;indices2[0], indices2.size() * sizeof(unsigned short) ); //Generate VAO glGenVertexArrays(1, &amp;VertexArrayID2); glBindVertexArray(VertexArrayID2); // 1rst attribute buffer : vertices glEnableVertexAttribArray(0); glBindBuffer(GL_ARRAY_BUFFER, vertexbuffer2); glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 0, (void*)0 ); // 2nd attribute buffer : normals glEnableVertexAttribArray(1); glBindBuffer(GL_ARRAY_BUFFER, normalbuffer2); glVertexAttribPointer(1, 3, GL_FLOAT, GL_FALSE, 0, (void*)0 ); // 3nd attribute buffer : UVs glEnableVertexAttribArray(2); glBindBuffer(GL_ARRAY_BUFFER, uvbuffer2); glVertexAttribPointer(2, 2, GL_FLOAT, GL_FALSE, 0, (void*)0 ); // 4th attribute buffer : colors glEnableVertexAttribArray(3); glBindBuffer(GL_ARRAY_BUFFER, colorbuffer2); glVertexAttribPointer(3, 4, GL_FLOAT, GL_FALSE, 0, (void*)0 ); // Index buffer glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, elementbuffer2); </code></pre> <p>Now Drawing</p> <pre><code>do{ glUseProgram(programID); glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, elementbuffer); // Draw the primatives ! glDrawElements(GL_POINTS, 2, GL_UNSIGNED_SHORT, (void*)0); glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, elementbuffer2); glDrawElements(GL_LINES, 2, GL_UNSIGNED_SHORT, (void*)0); glUseProgram(0); glfwSwapBuffers(); ..} </code></pre> <p>So when I init the 2nd VBO it over and I only get 2 blue dots and not 2 dots and a line</p>
 

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