初学者关于OpenGL 的问题

ibmc490365333 2014-09-20 12:44:12

#include <GL/gl.h>

#include <GL/freeglut.h>

void display();



int main(int argc, char ** argv){

    glutInit(&argc, argv);

    glutInitDisplayMode(GLUT_RGBA);

    glutInitWindowSize(512, 512);

    glutCreateWindow(argv[0]);

    glutDisplayFunc(display);

    glutMainLoop();

}



void display(){

    glClearColor(0.0, 0.0, 0.0, 0.0);

    glClear(GL_COLOR_BUFFER_BIT);



    GLuint array;

    glGenVertexArrays(1, &array);

    glBindVertexArray(array);



    GLfloat vertex_data[3][3] = {{-1.0, -1.0, 0.0}, {1.0, -1.0, 0.0}, {0.0, 1.0, 0.0}};





    GLuint buffer;

    buffer=glGenBuffers(1, &buffer);

    glBindBuffer(GL_ARRAY_BUFFER, buffer);

    glBufferData(GL_ARRAY_BUFFER, vertex_data, GL_STATIC_DRAW);



    GLuint VertexShader = glCreateShader(GL_VERTEX_SHADER);

    GLuint FragmentShader = glCreateShader(GL_FRAGMENT_SHADER);

    char * VertexShaderCode = "#version 120\nvoid main(){gl_Position = vec4(vertexPosition, 1.0);}\n";

    char * FragmentShaderCode = "#version 120\nvoid main(){gl_FragColor = vec4(1,0,0,1);}\n";

    glShaderSource(VertexShader, 1, &VertexShaderCode, NULL);

    glShaderSource(FragmentShader, 1, &FragmentShaderCode, NULL);

    glCompileShader(VertexShader);

    glCompileShader(FragmentShader);

    GLuint Program=glCreateProgram();

    glAttachShader(Program, VertexShader);

    glAttachShader(Program, FragmentShader);

    glLinkProgram(Program);

    glUseProgram(Program);



    GLuint vertexattrpos = glGetAttribLocation(Program, "vertexPosition");

    glEnableVertexAttribArray(vertexattrpos);

    glVertexAttribPointer(vertexattrpos, 3, GL_FLOAT, GL_FALSE, 0, (void *)0);



    glDrawArrays(GL_TRIANGLES, 0, 3);

    glFinish();

}