gistfile1.cpp

#include <iostream>
#include <cassert>

#define GLFW_INCLUDE_GL3
#include <GL/glfw.h>

#include <lgsl/runtime.hpp>

#include <gfx/mat4.h>

using namespace std;
using namespace gfx;

const char* const VertexProgramSource =
"float4 main(float4 In : ATTRIBUTE_0, "
"            uniform float4x4 Matrix) : POSITION "
"{"
"   return Matrix * In;"
"}"
;

const char* const FragmentProgramSource =
"float4 main(uniform float4 C) : COLOR "
"{"
"   return C;"
"}"
;

using namespace lgsl;

lgsl::opengl_3_runtime* Runtime;

lgsl::program VertexProgram;
lgsl::program FragmentProgram;

GLuint VAO;
GLuint VBO;

GLfloat Data[] =
{  -.5, -.5, 0, 1,
    .5, -.5, 0, 1,
     0,  .5, 0, 1,
};

float Rotation = 0.0;
const float RotationDelta = 0.6;
const float Color[] = { 0.0, 1.0, 0.0, 1.0 };

void init()
{
    glClearColor(0.5, 0.5, 0.5, 1.0);
    glEnable(GL_DEPTH_TEST);
    glClear(GL_COLOR_BUFFER_BIT);
    using namespace lgsl;
    Runtime = new opengl_3_runtime();
    VertexProgram = Runtime->create_program(lgsl::VERTEX_PROGRAM, VertexProgramSource);
    FragmentProgram = Runtime->create_program(lgsl::FRAGMENT_PROGRAM, FragmentProgramSource);
    Runtime->bind_program(VertexProgram);
    Runtime->bind_program(FragmentProgram);
    auto CParam = Runtime->get_program_parameter(FragmentProgram, "C");
    Runtime->parameter_value(FragmentProgram, CParam, Color, 4);
    Runtime->destroy_program_parameter(CParam);
    //
    glGenVertexArrays(1, &VAO);
    glBindVertexArray(VAO);
    glGenBuffers(1, &VBO);
    glBindBuffer(GL_ARRAY_BUFFER, VBO);
    glBufferData(GL_ARRAY_BUFFER, 16 * sizeof(GLfloat), Data, GL_STATIC_DRAW);
    glVertexAttribPointer((GLuint)0, 4, GL_FLOAT, GL_FALSE, 0, 0);
    glEnableVertexAttribArray(0);
}

int main(int argc, const char * argv[])
{
    glfwInit();
    glfwOpenWindowHint(GLFW_OPENGL_VERSION_MAJOR, 3);
    glfwOpenWindowHint(GLFW_OPENGL_VERSION_MINOR, 2);
    glfwOpenWindowHint(GLFW_OPENGL_PROFILE, GLFW_OPENGL_CORE_PROFILE);
    glfwOpenWindow(500, 500, 8, 8, 8, 8, 24, 8, GLFW_WINDOW);
    init();
    while(true)
    {
        if(!glfwGetWindowParam(GLFW_OPENED))
        {
  		break;
		}
        glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
        //
        auto Mat = rotation_matrix_deg(Rotation, Vec3(0, 1, 0));
        Rotation += RotationDelta;
        float Values[16];
        double* M = Mat;
        for(int i = 0; i < 16; ++i)
        {
            Values[i] = M[i];
        }
        auto MatrixParameter = Runtime->get_program_parameter(VertexProgram, "Matrix");
        Runtime->parameter_value(VertexProgram, MatrixParameter, Values, 16);
        //
        glBindVertexArray(VAO);
        glDrawArrays(GL_TRIANGLES, 0, 3);       // draw second object
        glfwSwapBuffers();
    }
    glfwTerminate();
    return 0;
}