Mesh.cpp

#include "Mesh.h"

Mesh::Mesh(vector<Vertex> vertices, vector<unsigned int> indices, Material material, glm::vec3 center)
{
    this->vertices = vertices;
    this->indices = indices;
    this->material = material;
    this->center = center;

    setupMesh();
}

void Mesh::setupMesh()
{
    glGenVertexArrays(1, &VAO);
    glGenBuffers(1, &VBO);
    glGenBuffers(1, &EBO);

    // VAO
    glBindVertexArray(VAO);
    glBindBuffer(GL_ARRAY_BUFFER, VBO);
    glBufferData(GL_ARRAY_BUFFER, vertices.size() * sizeof(Vertex), &vertices[0], GL_STATIC_DRAW);
    // VBO
    glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, EBO);
    glBufferData(GL_ELEMENT_ARRAY_BUFFER, indices.size() * sizeof(unsigned int), &indices[0], GL_STATIC_DRAW);

    // 顶点位置
    glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, sizeof(Vertex), (void*)0);
    glEnableVertexAttribArray(0);
    // 顶点法线
    glVertexAttribPointer(1, 3, GL_FLOAT, GL_FALSE, sizeof(Vertex), (void*)offsetof(Vertex, normal));
    glEnableVertexAttribArray(1);
    // 顶点纹理坐标
    glVertexAttribPointer(2, 2, GL_FLOAT, GL_FALSE, sizeof(Vertex), (void*)offsetof(Vertex, texCoord));
    glEnableVertexAttribArray(2);
}

void Mesh::draw(Shader shader, bool center, glm::vec3 scale)
{
    unsigned int diffuseNr = 1;
    unsigned int specularNr = 1;
    for (unsigned int i = 0; i < material.textures.size(); i++)
    {
        glActiveTexture(GL_TEXTURE0 + i);
        string name = material.textures[i].type;

        shader.setInt(("material." + name).c_str(), i);
        glBindTexture(GL_TEXTURE_2D, material.textures[i].id);
    }
    shader.setInt("material.shininess", material.shininess);
    glm::mat4 model = glm::mat4(1);
    model = glm::scale(model, scale);
    if (center)
    {
        model = glm::translate(model, -this->center);
    }
    shader.setMat4("model", model);

    glBindVertexArray(VAO);
    glDrawElements(GL_TRIANGLES, indices.size(), GL_UNSIGNED_INT, 0);
}