GLSL + Optional features = OpenGL Mathematics (GLM) A C++ mathematics library for graphics programming 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: // glm::vec3, glm::vec4, glm::ivec4, glm::mat4 #include <glm/glm.hpp> // glm::perspective #include <glm/gtc/matrix_projection.hpp> // glm::translate, glm::rotate, glm::scale #include <glm/gtc/matrix_transform.hpp> // glm::value_ptr #include <glm/gtc/type_ptr.hpp> { 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)); } Vector types: #include <glm/glm.hpp> #include <glm/gtx/type_precision.hpp> std::size_t const VertexCount = 4; // Float quad geometry std::size_t const PositionSizeF32 = VertexCount * sizeof(glm::vec2); glm::vec2 const PositionDataF32[VertexCount] = { glm::vec2(-1.0f,-1.0f), glm::vec2( 1.0f,-1.0f), glm::vec2( 1.0f, 1.0f), glm::vec2(-1.0f, 1.0f) }; // Half-float quad geometry std::size_t const PositionSizeF16 = VertexCount * sizeof(glm::hvec2); glm::hvec2 const PositionDataF16[VertexCount] = { glm::hvec2(-1.0f, -1.0f), glm::hvec2( 1.0f, -1.0f), glm::hvec2( 1.0f, 1.0f), glm::hvec2(-1.0f, 1.0f) }; // 8 bits signed integer quad geometry std::size_t const PositionSizeI8 = VertexCount * sizeof(glm::i8vec2); glm::i8vec2 const PositionDataI8[VertexCount] = { glm::i8vec2(-1,-1), glm::i8vec2( 1,-1), glm::i8vec2( 1, 1), glm::i8vec2(-1, 1) }; // 32 bits signed integer quad geometry std::size_t const PositionSizeI32 = VertexCount * sizeof(glm::i32vec2); glm::i32vec2 const PositionDataI32[VertexCount] = { glm::i32vec2 (-1,-1), glm::i32vec2 ( 1,-1), glm::i32vec2 ( 1, 1), glm::i32vec2 (-1, 1) }; Lighting: #include <glm/glm.hpp> #include <glm/gtx/random.hpp> glm::vec3 lighting ( intersection const & Intersection, material const & Material, light const & Light, glm::vec3 const & View ) { glm::vec3 Color = glm::vec3(0.0f); glm::vec3 LightVertor = glm::normalize( Light.position() - Intersection.globalPosition() + glm::vecRand3(0.0f, Light.inaccuracy()); if(!shadow( Intersection.globalPosition(), Light.position(), LightVertor)) { float Diffuse = glm::dot(Intersection.normal(), LightVector); if(Diffuse <= 0.0f) return Color; if(Material.isDiffuse()) Color += Light.color() * Material.diffuse() * Diffuse; if(Material.isSpecular()) { glm::vec3 Reflect = glm::reflect( glm::normalize(-LightVector), glm::normalize(Intersection.normal())); float Dot = glm::dot(Reflect, View); float Base = Dot > 0.0f ? Dot : 0.0f; float Specular = glm::pow(Base, Material.exponent()); Color += Material.specular() * Specular; } } Copyright © 2005 - 2011G-Truc Creation