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| #include <GL/glew.h>
#include <GL/freeglut.h>
#include <iostream>
#include <fstream>
unsigned int vertexID, fragmentID, programID;
int positionIndex, colorIndex;
GLuint bufferVBO[3];
GLfloat cubeArray[24] = {
1.0f, 0.0f, 0.0f, -1.0f, 1.0f, -1.0f,
1.0f, 0.0f, 1.0f, -1.0f, -1.0f, -1.0f,
1.0f, 1.0f, 1.0f, -1.0f, 1.0f, 1.0f,
0.0f, 0.0f, 1.0f, -1.0f, -1.0f, 1.0f
};
GLfloat colorArray[24] = {
0.0f, 1.0f, 0.0f, 1.0f, 1.0f, 1.0f,
0.0f, 1.0f, 1.0f, 1.0f, -1.0f, 1.0f,
1.0f, 1.0f, 0.0f, 1.0f, 1.0f, -1.0f,
1.0f, 1.0f, 1.0f, 1.0f, -1.0f, -1.0f
};
GLuint indiceArray[36] = {
0,1,2,2,1,3,
4,5,6,6,5,7,
3,1,5,5,1,7,
0,2,6,6,2,4,
6,7,0,0,7,1,
2,3,4,4,3,5
};
//chargemetn des source d'un shader
char* loadSource(const char *filename)
{
char *src = NULL; /* code source de notre shader */
FILE *fp = NULL; /* fichier */
long size; /* taille du fichier */
long i; /* compteur */
fp = fopen(filename, "r");
if(fp == NULL)
{
fprintf(stderr, "impossible d'ouvrir le fichier '%s'\n", filename);
return NULL;
}
fseek(fp, 0, SEEK_END);
size = ftell(fp);
rewind(fp);
src = new char(size+1);
if(src == NULL)
{
fclose(fp);
fprintf(stderr, "erreur d'allocation de memoire!\n");
return NULL;
}
for(i=0; i<size; i++)
src[i] = fgetc(fp);
src[size] = '\0';
fclose(fp);
return src;
}
void reshapeGL(int h, int w)
{
}
//affichage opengl
void displayGL(void)
{
glEnableClientState(GL_VERTEX_ARRAY);
glEnableClientState(GL_INDEX_ARRAY);
glBindBuffer(GL_ARRAY_BUFFER, bufferVBO[0]);
glEnableVertexAttribArray(positionIndex);
glVertexAttribPointer(positionIndex, 3, GL_FLOAT, GL_FALSE, 0, &cubeArray[0]);
glBindBuffer(GL_ARRAY_BUFFER, bufferVBO[1]);
glEnableVertexAttribArray(colorIndex);
glVertexAttribPointer(colorIndex, 3, GL_FLOAT, GL_FALSE, 0, &colorArray[0]);
glBindBuffer(GL_ARRAY_BUFFER, bufferVBO[2]);
glDrawElements(GL_TRIANGLES, 36, GL_UNSIGNED_INT, &indiceArray[0]);
glDisableVertexAttribArray(colorIndex);
glDisableVertexAttribArray(positionIndex);
glDisableClientState(GL_VERTEX_ARRAY);
glDisableClientState(GL_INDEX_ARRAY);
glFlush();
}
//initialisation opengl
void initGL(int argc, char *argv[])
{
glutInit(&argc, argv);
glutInitContextVersion(3,3);
glutInitContextFlags (GLUT_FORWARD_COMPATIBLE | GLUT_DEBUG);
glutInitDisplayMode(GLUT_DEPTH | GLUT_DOUBLE | GLUT_RGBA);
glutInitWindowSize(640,480);
glutInitWindowPosition(50,50);
glutCreateWindow("test shader");
glutDisplayFunc(displayGL);
glutReshapeFunc(reshapeGL);
}
int main(int argc, char *argv[])
{
int OpenGLVersion[2];
GLint erreurCompilation = 0, tailleErreur = 0;
char *erreur = NULL;
//intialisation
initGL(argc,argv);
GLenum err=glewInit();
if(err!=GLEW_OK)
{
std::cout << "glewInit failed, aborting." << std::endl;
exit(1);
}
glGetIntegerv(GL_MAJOR_VERSION, &OpenGLVersion[0]);
glGetIntegerv(GL_MINOR_VERSION, &OpenGLVersion[1]);
std::cout << "OpenGL version = " << OpenGLVersion[0] << ".";
std::cout << OpenGLVersion[1] << std::endl << std::endl;
GLenum errorState = GL_NO_ERROR;
glClearColor(0.0,0.5,0.0,1.0);
glClearDepth(1.0);
glDepthFunc(GL_LESS);
glEnable(GL_DEPTH_TEST);
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
gluPerspective(45.0f,(GLfloat)640/(GLfloat)480,0.1f,100.0f);
glMatrixMode(GL_MODELVIEW);
//creation des shaders
vertexID = glCreateShader(GL_VERTEX_SHADER);
const char * vertexSource = loadSource("shader/test.vert");
glShaderSource(vertexID, 1, &vertexSource, NULL);
fragmentID = glCreateShader(GL_FRAGMENT_SHADER);
const char * fragmentSource = loadSource("shader/test.frag");
glShaderSource(fragmentID, 1, &fragmentSource, NULL);
//compilation des shaders
glCompileShader(vertexID);
glCompileShader(fragmentID);
glGetShaderiv(vertexID, GL_COMPILE_STATUS, &erreurCompilation);
if(erreurCompilation != GL_TRUE)
{
glGetShaderiv(vertexID, GL_INFO_LOG_LENGTH, &tailleErreur);
erreur = new char(tailleErreur + 1);
glGetInfoLogARB(vertexID, tailleErreur, &tailleErreur, erreur);
printf("%s\n\n", erreur);
return -1;
}
//creation du programme
programID = glCreateProgram();
//liaison des shader au programme
glAttachShader(programID, vertexID);
glAttachShader(programID, fragmentID);
glLinkProgram(programID);
//activation des tableau de vertex et index
glEnableClientState(GL_VERTEX_ARRAY);
glEnableClientState(GL_INDEX_ARRAY);
//creation de vbo
glGenBuffers(3, bufferVBO);
//mise en tampon des buffers
glBindBuffer(GL_ARRAY_BUFFER, bufferVBO[0]);
glBufferData(GL_ARRAY_BUFFER, sizeof(cubeArray), cubeArray, GL_STATIC_DRAW);
positionIndex = glGetAttribLocation(programID, "invertex");
glBindAttribLocation(programID, positionIndex, "invertex");
glBindBuffer(GL_ARRAY_BUFFER, bufferVBO[1]);
glBufferData(GL_ARRAY_BUFFER, sizeof(colorArray), colorArray, GL_STATIC_DRAW);
colorIndex = glGetAttribLocation(programID, "incolor");
glBindAttribLocation(programID, colorIndex, "incolor");
glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, bufferVBO[2]);
glBufferData(GL_ELEMENT_ARRAY_BUFFER, sizeof(indiceArray), indiceArray, GL_STATIC_DRAW);
//verification des index
std::cout << "valeur des index : " << positionIndex << " " << colorIndex << std::endl;
//utilisation du programme
glUseProgram(programID);
//boucle opengl
glutMainLoop();
glDisableClientState(GL_VERTEX_ARRAY);
glDisableClientState(GL_INDEX_ARRAY);
} |
opengl vbo shader
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