OpenGL Mathematics

GLM (OpenGL Mathematics) is an OpenGL utility library providing to C++ programmer all classes and functions allowing to use data for OpenGL ^[1].

One GLM characteristic is that GLM implementation is based on GLSL (OpenGL Shading Language) specification ^[2].

GLM source code is available under the MIT license.

Code samples

// Compute a triangle normal:
#include <glm/glm.hpp>
 
void computeNormal(triangle & Triangle)
{
  glm::vec3 const & a = Triangle.Position[0];
  glm::vec3 const & b = Triangle.Position[1];
  glm::vec3 const & c = Triangle.Position[2];
  Triangle.Normal = glm::normalize(glm::cross(c - a, b - a));
}

// Matrix transform:
#include <glm/glm.hpp> // glm::vec3, glm::vec4, glm::ivec4, glm::mat4
#include <glm/gtc/matrix_projection.hpp> // glm::perspective
#include <glm/gtc/matrix_transform.hpp> // glm::translate, glm::rotate, glm::scale
#include <glm/gtc/type_ptr.hpp> // glm::value_ptr
 
void transform()
{
  glm::mat4 Projection = glm::perspective(45.0f, 4.0f / 3.0f, 0.1f, 100.f);
  glm::mat4 ViewTranslate = glm::translate(glm::mat4(1.0f), glm::vec3(0.0f, 0.0f, -Translate));
  glm::mat4 ViewRotateX = glm::rotate(ViewTranslate, Rotate.y, glm::vec3(-1.0f, 0.0f, 0.0f));
  glm::mat4 View = glm::rotate(ViewRotateX, Rotate.x, glm::vec3(0.0f, 1.0f, 0.0f));
  glm::mat4 Model = glm::scale(glm::mat4(1.0f), glm::vec3(0.5f));
  glm::mat4 MVP = Projection * View * Model;
  glUniformMatrix4fv(LocationMVP, 1, GL_FALSE, glm::value_ptr(MVP));
}

References

1. ^ http://www.opengl.org/registry/doc/glspec41.core.20100725.pdf
2. ^ http://www.opengl.org/registry/doc/GLSLangSpec.4.10.6.clean.pdf

External links

• (English) http://glm.g-truc.net
• (English) https://sourceforge.net/projects/ogl-math/