Mesh.cpp

#include "Mesh.h"

Mesh::Mesh(const std::vector<Vertex> &vertices, const std::vector<unsigned int> &indices, const std::vector<Texture> &textures) :
	m_vertices(vertices),
	m_indices(indices),
	m_textures(textures)
{
	glGenVertexArrays(1, &m_VAO);
	glGenBuffers(1, &m_VBO);
	glGenBuffers(1, &m_EBO);

	glBindVertexArray(m_VAO);
	
	glBindBuffer(GL_ARRAY_BUFFER, m_VBO);
	glBufferData(GL_ARRAY_BUFFER, m_vertices.size() * sizeof(Vertex), &m_vertices[0], GL_STATIC_DRAW);

	glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, m_EBO);
	glBufferData(GL_ELEMENT_ARRAY_BUFFER, m_indices.size() * sizeof(unsigned int), &m_indices[0], GL_STATIC_DRAW);

	glEnableVertexAttribArray(0);
	glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, sizeof(Vertex), (void*) 0);

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

	glEnableVertexAttribArray(2);
	glVertexAttribPointer(2, 2, GL_FLOAT, GL_FALSE, sizeof(Vertex), (void*) offsetof(Vertex, TexCoords));
	
	glBindVertexArray(0);
}

void Mesh::draw(const Shader& shader) const {
	unsigned int diffuseNum = 1;
	unsigned int specularNum = 1;
	unsigned int normalNum = 1;
	unsigned int heightNum = 1;
	for (unsigned int i = 0; i < m_textures.size(); i++) {
		glActiveTexture(GL_TEXTURE0 + i);
		std::string number;
		std::string name = m_textures[i].type;
		if (name == "texture_diffuse") {
			number = std::to_string(diffuseNum);
		}
		else if (name == "texture_specular") {
			number = std::to_string(specularNum);
		}
		else if (name == "texture_normal") {
			number = std::to_string(normalNum);
		}
		else if (name == "texture_height") {
			number = std::to_string(heightNum);
		}

		shader.setInt((name + number).c_str(), i);
		glBindTexture(GL_TEXTURE_2D, m_textures[i].id);
	}

	shader.use();
	glBindVertexArray(m_VAO);
	glDrawElements(GL_TRIANGLES, static_cast<unsigned int>(m_indices.size()), GL_UNSIGNED_INT, 0);
	glBindVertexArray(0);

	glActiveTexture(GL_TEXTURE0);
}