restructure v2

engine/Backend/Mesh.cpp

@@ -0,0 +1,101 @@
+
+#include "Mesh.h"
+
+#include <glad/glad.h> // holds all OpenGL type declarations
+#include <glm/gtc/matrix_transform.hpp>
+#include <string>
+#include <vector>
+
+// constructor
+Mesh::Mesh(vector<Vertex> vertices, vector<unsigned int> indices, vector<Texture> textures)
+{
+    this->vertices = vertices;
+    this->indices = indices;
+    this->textures = textures;
+
+    // now that we have all the required data, set the vertex buffers and its attribute pointers.
+    setupMesh();
+}
+
+// render the mesh
+void Mesh::Draw(Shader &shader)
+{
+    // bind appropriate textures
+    unsigned int diffuseNr  = 1;
+    unsigned int specularNr = 1;
+    unsigned int normalNr   = 1;
+    unsigned int heightNr   = 1;
+    for(unsigned int i = 0; i < textures.size(); i++)
+    {
+        glActiveTexture(GL_TEXTURE0 + i); // active proper texture unit before binding
+        // retrieve texture number (the N in diffuse_textureN)
+        string number;
+        string name = textures[i].type;
+        if(name == "texture_diffuse")
+            number = std::to_string(diffuseNr++);
+        else if(name == "texture_specular")
+            number = std::to_string(specularNr++); // transfer unsigned int to string
+        else if(name == "texture_normal")
+            number = std::to_string(normalNr++); // transfer unsigned int to string
+         else if(name == "texture_height")
+            number = std::to_string(heightNr++); // transfer unsigned int to string
+
+        // now set the sampler to the correct texture unit
+        glUniform1i(glGetUniformLocation(shader.ID, (name + number).c_str()), i);
+        // and finally bind the texture
+        glBindTexture(GL_TEXTURE_2D, textures[i].id);
+    }
+
+    // draw mesh
+    glBindVertexArray(VAO);
+    glDrawElements(GL_TRIANGLES, static_cast<unsigned int>(indices.size()), GL_UNSIGNED_INT, 0);
+    glBindVertexArray(0);
+
+    // always good practice to set everything back to defaults once configured.
+    glActiveTexture(GL_TEXTURE0);
+}
+
+// initializes all the buffer objects/arrays
+void Mesh::setupMesh()
+{
+    // create buffers/arrays
+    glGenVertexArrays(1, &VAO);
+    glGenBuffers(1, &VBO);
+    glGenBuffers(1, &EBO);
+
+    glBindVertexArray(VAO);
+    // load data into vertex buffers
+    glBindBuffer(GL_ARRAY_BUFFER, VBO);
+    // A great thing about structs is that their memory layout is sequential for all its items.
+    // The effect is that we can simply pass a pointer to the struct and it translates perfectly to a glm::vec3/2 array which
+    // again translates to 3/2 floats which translates to a byte array.
+    glBufferData(GL_ARRAY_BUFFER, vertices.size() * sizeof(Vertex), &vertices[0], GL_STATIC_DRAW);
+
+    glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, EBO);
+    glBufferData(GL_ELEMENT_ARRAY_BUFFER, indices.size() * sizeof(unsigned int), &indices[0], GL_STATIC_DRAW);
+
+    // set the vertex attribute pointers
+    // vertex Positions
+    glEnableVertexAttribArray(0);
+    glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, sizeof(Vertex), (void*)0);
+    // vertex normals
+    glEnableVertexAttribArray(1);
+    glVertexAttribPointer(1, 3, GL_FLOAT, GL_FALSE, sizeof(Vertex), (void*)offsetof(Vertex, Normal));
+    // vertex texture coords
+    glEnableVertexAttribArray(2);
+    glVertexAttribPointer(2, 2, GL_FLOAT, GL_FALSE, sizeof(Vertex), (void*)offsetof(Vertex, TexCoords));
+    // vertex tangent
+    glEnableVertexAttribArray(3);
+    glVertexAttribPointer(3, 3, GL_FLOAT, GL_FALSE, sizeof(Vertex), (void*)offsetof(Vertex, Tangent));
+    // vertex bitangent
+    glEnableVertexAttribArray(4);
+    glVertexAttribPointer(4, 3, GL_FLOAT, GL_FALSE, sizeof(Vertex), (void*)offsetof(Vertex, Bitangent));
+	// ids
+	glEnableVertexAttribArray(5);
+	glVertexAttribIPointer(5, 4, GL_INT, sizeof(Vertex), (void*)offsetof(Vertex, m_BoneIDs));
+
+	// weights
+	glEnableVertexAttribArray(6);
+	glVertexAttribPointer(6, 4, GL_FLOAT, GL_FALSE, sizeof(Vertex), (void*)offsetof(Vertex, m_Weights));
+    glBindVertexArray(0);
+}