Drawing a simple triangle horror when using std::vector
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this is bullshit, the first VAO without std::vector get drawn but not the second with vector :confused: : Vector3f Vertices[4]; Vertices[0] = Vector3f(-1.0f, -1.0f, 0.5773f); Vertices[1] = Vector3f(0.0f, -1.0f, -1.15475f); Vertices[2] = Vector3f(1.0f, -1.0f, 0.5773f); Vertices[3] = Vector3f(0.0f, 1.0f, 0.0f); unsigned int Indices[] = { 0, 3, 1, 1, 3, 2, 2, 3, 0, 0, 1, 2 }; GLuint VBO[2]; GLuint IBO[2]; unsigned int id[2]; glGenVertexArrays(2, id); glGenBuffers(2, VBO); glGenBuffers(2, IBO); glBindVertexArray(id[0]); glBindBuffer(GL_ARRAY_BUFFER, VBO[0]); glBufferData(GL_ARRAY_BUFFER, sizeof(Vertices), Vertices, GL_STATIC_DRAW); glEnableVertexAttribArray(0); glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 0, 0); glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, IBO[0]); glBufferData(GL_ELEMENT_ARRAY_BUFFER, sizeof(Indices), Indices, GL_STATIC_DRAW); struct Vertex { Vector3f position; //Vector2f texCoord; //Vector3f normal; //int Boneindices[4]; //float Weights[4]; }; vector Vertices2; Vertex* v=new Vertex(); v->position = Vector3f(-1.0f, -0.0f, 0); Vertices2.push_back(v); v->position = Vector3f(1.0f, -0.0f, -1); Vertices2.push_back(v); v->position = Vector3f(1.0f, -0.0f, 0); Vertices2.push_back(v); v->position = Vector3f(0.0f, 1.0f, 0.0f); Vertices2.push_back(v); struct Triangle { int indices[3]; }; Triangle* t = new Triangle(); t->indices[0]=0; t->indices[1]=3; t->indices[2]=1; vector Indices2; Indices2.push_back(t); t->indices[0] = 1; t->indices[1] = 3; t->indices[2] = 2; Indices2.push_back(t); t->indices[0] = 2; t->indices[1] = 3; t->indices[2] = 0; Indices2.push_back(t); t->indices[0] = 0; t->indices[1] = 1; t->indices[2] = 2; Indices2.push_back(t); glBindVertexArray(id[1]); glBindBuffer(GL_ARRAY_BUFFER, VBO[1]); glBufferData(GL_ARRAY_BUFFER, sizeof(Vertex)* Vertices2.size(), &Vertices2[0], GL_STATIC_DRAW); glEnableVertexAttribArray(0); glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 0, 0); glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, IBO[1]); glBufferData(GL_ELEMENT_ARRAY_BUFFER, sizeof(Triangle)* Indices2.size(), &Indices2[0], GL_STATIC_DRAW); for (size_t i = 0; i < 2; i++) { glBindVertexArray(id[i]); glDrawElements(GL_TRIANGLES, 12, GL_UNSIGNED_INT, 0); glBindVertexArray(0); }
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this is bullshit, the first VAO without std::vector get drawn but not the second with vector :confused: : Vector3f Vertices[4]; Vertices[0] = Vector3f(-1.0f, -1.0f, 0.5773f); Vertices[1] = Vector3f(0.0f, -1.0f, -1.15475f); Vertices[2] = Vector3f(1.0f, -1.0f, 0.5773f); Vertices[3] = Vector3f(0.0f, 1.0f, 0.0f); unsigned int Indices[] = { 0, 3, 1, 1, 3, 2, 2, 3, 0, 0, 1, 2 }; GLuint VBO[2]; GLuint IBO[2]; unsigned int id[2]; glGenVertexArrays(2, id); glGenBuffers(2, VBO); glGenBuffers(2, IBO); glBindVertexArray(id[0]); glBindBuffer(GL_ARRAY_BUFFER, VBO[0]); glBufferData(GL_ARRAY_BUFFER, sizeof(Vertices), Vertices, GL_STATIC_DRAW); glEnableVertexAttribArray(0); glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 0, 0); glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, IBO[0]); glBufferData(GL_ELEMENT_ARRAY_BUFFER, sizeof(Indices), Indices, GL_STATIC_DRAW); struct Vertex { Vector3f position; //Vector2f texCoord; //Vector3f normal; //int Boneindices[4]; //float Weights[4]; }; vector Vertices2; Vertex* v=new Vertex(); v->position = Vector3f(-1.0f, -0.0f, 0); Vertices2.push_back(v); v->position = Vector3f(1.0f, -0.0f, -1); Vertices2.push_back(v); v->position = Vector3f(1.0f, -0.0f, 0); Vertices2.push_back(v); v->position = Vector3f(0.0f, 1.0f, 0.0f); Vertices2.push_back(v); struct Triangle { int indices[3]; }; Triangle* t = new Triangle(); t->indices[0]=0; t->indices[1]=3; t->indices[2]=1; vector Indices2; Indices2.push_back(t); t->indices[0] = 1; t->indices[1] = 3; t->indices[2] = 2; Indices2.push_back(t); t->indices[0] = 2; t->indices[1] = 3; t->indices[2] = 0; Indices2.push_back(t); t->indices[0] = 0; t->indices[1] = 1; t->indices[2] = 2; Indices2.push_back(t); glBindVertexArray(id[1]); glBindBuffer(GL_ARRAY_BUFFER, VBO[1]); glBufferData(GL_ARRAY_BUFFER, sizeof(Vertex)* Vertices2.size(), &Vertices2[0], GL_STATIC_DRAW); glEnableVertexAttribArray(0); glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 0, 0); glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, IBO[1]); glBufferData(GL_ELEMENT_ARRAY_BUFFER, sizeof(Triangle)* Indices2.size(), &Indices2[0], GL_STATIC_DRAW); for (size_t i = 0; i < 2; i++) { glBindVertexArray(id[i]); glDrawElements(GL_TRIANGLES, 12, GL_UNSIGNED_INT, 0); glBindVertexArray(0); }
Your vector contains pointers to
vertex, not the actual vertices. In fact it contains the same pointer four times, so even if OpenGL can handle pointers to vertex data you only have the same vertex repeated. The index buffer suffers from the same problem. -
this is bullshit, the first VAO without std::vector get drawn but not the second with vector :confused: : Vector3f Vertices[4]; Vertices[0] = Vector3f(-1.0f, -1.0f, 0.5773f); Vertices[1] = Vector3f(0.0f, -1.0f, -1.15475f); Vertices[2] = Vector3f(1.0f, -1.0f, 0.5773f); Vertices[3] = Vector3f(0.0f, 1.0f, 0.0f); unsigned int Indices[] = { 0, 3, 1, 1, 3, 2, 2, 3, 0, 0, 1, 2 }; GLuint VBO[2]; GLuint IBO[2]; unsigned int id[2]; glGenVertexArrays(2, id); glGenBuffers(2, VBO); glGenBuffers(2, IBO); glBindVertexArray(id[0]); glBindBuffer(GL_ARRAY_BUFFER, VBO[0]); glBufferData(GL_ARRAY_BUFFER, sizeof(Vertices), Vertices, GL_STATIC_DRAW); glEnableVertexAttribArray(0); glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 0, 0); glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, IBO[0]); glBufferData(GL_ELEMENT_ARRAY_BUFFER, sizeof(Indices), Indices, GL_STATIC_DRAW); struct Vertex { Vector3f position; //Vector2f texCoord; //Vector3f normal; //int Boneindices[4]; //float Weights[4]; }; vector Vertices2; Vertex* v=new Vertex(); v->position = Vector3f(-1.0f, -0.0f, 0); Vertices2.push_back(v); v->position = Vector3f(1.0f, -0.0f, -1); Vertices2.push_back(v); v->position = Vector3f(1.0f, -0.0f, 0); Vertices2.push_back(v); v->position = Vector3f(0.0f, 1.0f, 0.0f); Vertices2.push_back(v); struct Triangle { int indices[3]; }; Triangle* t = new Triangle(); t->indices[0]=0; t->indices[1]=3; t->indices[2]=1; vector Indices2; Indices2.push_back(t); t->indices[0] = 1; t->indices[1] = 3; t->indices[2] = 2; Indices2.push_back(t); t->indices[0] = 2; t->indices[1] = 3; t->indices[2] = 0; Indices2.push_back(t); t->indices[0] = 0; t->indices[1] = 1; t->indices[2] = 2; Indices2.push_back(t); glBindVertexArray(id[1]); glBindBuffer(GL_ARRAY_BUFFER, VBO[1]); glBufferData(GL_ARRAY_BUFFER, sizeof(Vertex)* Vertices2.size(), &Vertices2[0], GL_STATIC_DRAW); glEnableVertexAttribArray(0); glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 0, 0); glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, IBO[1]); glBufferData(GL_ELEMENT_ARRAY_BUFFER, sizeof(Triangle)* Indices2.size(), &Indices2[0], GL_STATIC_DRAW); for (size_t i = 0; i < 2; i++) { glBindVertexArray(id[i]); glDrawElements(GL_TRIANGLES, 12, GL_UNSIGNED_INT, 0); glBindVertexArray(0); }
Isawyouoo wrote:
this is bullshit
Well you wrote it. Look at the following line:
glBufferData(GL_ARRAY_BUFFER, sizeof(Vertex)* Vertices2.size(), &Vertices2[0], GL_STATIC_DRAW);
The third parameter is supposed to be a pointer to the data you wish to copy, but you are passing a pointer to a pointer. The vector contains a list of pointers to vertex elements, so
&Vertices2[0]is the address of the first pointer item in the vector. It should be:glBufferData(GL_ARRAY_BUFFER, sizeof(Vertex)* Vertices2.size(), Vertices2[0], GL_STATIC_DRAW);
Without the
&on parameter three.