#Dmesh tutorial code

Thanks to this useful property we can directly pass a pointer to a large list of Vertex structs as the buffer's data and they translate perfectly to what glBufferData expects as its argument: For example, if we have a filled Vertex struct, its memory layout would be equal to: That is, if we were to represent a struct as an array of data, it would only contain the struct's variables in sequential order which directly translates to a float (actually byte) array that we want for an array buffer. Structs have a great property in C++ that their memory layout is sequential.

#Dmesh tutorial code

The code is not much different from what you'd expect, but a few little tricks were used with the help of the Vertex struct. GlVertexAttribPointer(2, 2, GL_FLOAT, GL_FALSE, sizeof(Vertex), (void*)offsetof(Vertex, TexCoords))

GlVertexAttribPointer(1, 3, GL_FLOAT, GL_FALSE, sizeof(Vertex), (void*)offsetof(Vertex, Normal)) GlVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, sizeof(Vertex), (void*)0) GlBufferData(GL_ELEMENT_ARRAY_BUFFER, indices.size() * sizeof(unsigned int), GlBindBuffer(GL_ELEMENT_ARRAY_BUFFER, EBO) GlBufferData(GL_ARRAY_BUFFER, vertices.size() * sizeof(Vertex), &vertices, GL_STATIC_DRAW) By now you should have no trouble with these concepts, but we've spiced it up a bit this time with the introduction of vertex data in structs: We do need to setup the appropriate buffers and specify the vertex shader layout via vertex attribute pointers. Thanks to the constructor we now have large lists of mesh data that we can use for rendering.

Let's delve right into the setupMesh function now. Mesh(vector vertices, vector indices, vector textures) We also call the setupMesh function in the constructor: We simply set the class's public variables with the constructor's corresponding argument variables. The function content of the constructor is pretty straightforward. Note that we give a shader to the Draw function by passing the shader to the mesh we can set several uniforms before drawing (like linking samplers to texture units). In the constructor we give the mesh all the necessary data, we initialize the buffers in the setupMesh function, and finally draw the mesh via the Draw function. Mesh(vector vertices, vector indices, vector textures) Īs you can see, the class isn't too complicated. Knowing the actual representation of a vertex and a texture we can start defining the structure of the mesh class: We store the id of the texture and its type e.g. Next to a Vertex struct we also want to organize the texture data in a Texture struct: We store each of the required vertex attributes in a struct called Vertex. Now that we set the minimal requirements for a mesh class we can define a vertex in OpenGL: A mesh should also contain indices for indexed drawing, and material data in the form of textures (diffuse/specular maps). A mesh should at least need a set of vertices, where each vertex contains a position vector, a normal vector, and a texture coordinate vector. Let's review a bit of what we've learned so far to think about what a mesh should minimally have as its data. We learned from the previous chapter that a mesh represents a single drawable entity, so let's start by defining a mesh class of our own. What we eventually want is to transform that data to a format that OpenGL understands so that we can render the objects. With Assimp we can load many different models into the application, but once loaded they're all stored in Assimp's data structures.