Mesh.cpp

#include "Mesh.h"

Mesh::Mesh(std::vector<Vertex> vertices, std::vector<unsigned int> indices, std::vector<Texture> textures) {
	this->vertices = vertices;
	this->indices = indices;
	this->textures = textures;

	setupMesh();
}

void Mesh::Draw(Shader& shader) {
	unsigned int numDiffuseTextures = 1;
	unsigned int numSpecularTextures = 1;

	for (unsigned int i = 0; i < textures.size(); i++) {
		glActiveTexture(GL_TEXTURE0 + i);
		
		// Retrieve texture number (the N in textureDiffuseN in the shader)
		std::string number;
		std::string name = textures[i].type;

		if (name == "textureDiffuse") {
			number = std::to_string(numDiffuseTextures++);
		}
		else if (name == "textureSpecular") {
			number = std::to_string(numSpecularTextures++);
		}

		shader.setIntUniform(("material" + name + number).c_str(), i);
		glBindTexture(GL_TEXTURE_2D, textures[i].id);
	}
	glActiveTexture(GL_TEXTURE0);

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

void Mesh::setupMesh() {
	glGenVertexArrays(1, &vao);
	glGenBuffers(1, &vbo);
	glGenBuffers(1, &ebo);

	glBindVertexArray(vao);
	glBindBuffer(GL_ARRAY_BUFFER, vbo);
	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);

	// Vertex positions
	glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, sizeof(Vertex), (void*)0);
	glEnableVertexAttribArray(0);
	
	// Vertex normals
	glVertexAttribPointer(1, 3, GL_FLOAT, GL_FALSE, sizeof(Vertex), (void*)(offsetof(Vertex, Normal)));
	glEnableVertexAttribArray(1);

	// Vertex texture coords
	glVertexAttribPointer(2, 2, GL_FLOAT, GL_FALSE, sizeof(Vertex), (void*)(offsetof(Vertex, TexCoords)));
	glEnableVertexAttribArray(2);

	glBindVertexArray(0);
}