Files
coding-game/engine/src/renderer/mesh.cpp
2025-10-22 14:25:02 +02:00

65 lines
1.9 KiB
C++

#include <cstddef>
#include "engine/renderer/mesh.h"
namespace Engine {
Mesh::Mesh() {
m_vao = 0;
m_vbo = 0;
m_ebo = 0;
glGenVertexArrays(1, &m_vao);
glGenBuffers(1, &m_vbo);
glGenBuffers(1, &m_ebo);
glBindVertexArray(m_vao);
// VBO (vertex buffer)
glBindBuffer(GL_ARRAY_BUFFER, m_vbo);
glBufferData(GL_ARRAY_BUFFER, 0, nullptr, GL_DYNAMIC_DRAW);
// EBO (index buffer)
glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, m_ebo);
glBufferData(GL_ELEMENT_ARRAY_BUFFER, 0, nullptr, GL_DYNAMIC_DRAW);
// attributes
glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, sizeof(Vertex), reinterpret_cast<const void*>(offsetof(Vertex, m_position)));
glEnableVertexAttribArray(0);
glVertexAttribPointer(1, 3, GL_FLOAT, GL_FALSE, sizeof(Vertex), reinterpret_cast<const void*>(offsetof(Vertex, m_normal)));
glEnableVertexAttribArray(1);
glVertexAttribPointer(2, 2, GL_FLOAT, GL_FALSE, sizeof(Vertex), reinterpret_cast<const void*>(offsetof(Vertex, m_texCoord)));
glEnableVertexAttribArray(2);
glBindBuffer(GL_ARRAY_BUFFER, 0);
glBindVertexArray(0);
}
void Mesh::Upload() const {
glBindVertexArray(m_vao);
glBindBuffer(GL_ARRAY_BUFFER, m_vbo);
glBufferData(GL_ARRAY_BUFFER, m_vertexBuffer.size() * sizeof(Vertex), m_vertexBuffer.data(), GL_DYNAMIC_DRAW);
// Upload indices
glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, m_ebo);
glBufferData(GL_ELEMENT_ARRAY_BUFFER, m_indexBuffer.size() * sizeof(unsigned int), m_indexBuffer.data(), GL_DYNAMIC_DRAW);
glBindVertexArray(0);
}
void Mesh::Render(unsigned int count)
{
Bind();
if (count > 1) {
glDrawElementsInstanced(GL_TRIANGLES, static_cast<GLsizei>(m_indexBuffer.size()), GL_UNSIGNED_INT, 0, count);
} else {
glDrawElements(GL_TRIANGLES, static_cast<GLsizei>(m_indexBuffer.size()), GL_UNSIGNED_INT, 0);
}
Unbind();
}
}