#include <stdio.h>
#include <unistd.h>
#include <string.h>
#include <GL/glut.h>
#include "display.h"
#include "typedef.h"

unsigned char WIDTH  = 1;
unsigned char HEIGHT = 1;

GLubyte pixels[BUF_CAP] = {0};
static int fd;

void pixel(int x, int y, char *buf)
{
    int p = (y*WIDTH + x)*3;
    int b = ((HEIGHT-1-y)*WIDTH+x)*3;
    pixels[p+0] = buf[b+0];
    pixels[p+1] = buf[b+1];
    pixels[p+2] = buf[b+2];
}

void render()
{
    read(fd, &WIDTH,  sizeof(WIDTH));
    read(fd, &HEIGHT, sizeof(HEIGHT));

    char buf[BUF_CAP] = {0};
    if(read(fd, buf, sizeof(buf)) != -1)
        for(int i = 0; i < HEIGHT; i++)
            for(int j = 0; j < WIDTH; j++)
                pixel(j, i, buf);

    glClear(GL_COLOR_BUFFER_BIT);
    glDrawPixels(WIDTH, HEIGHT, GL_RGB, GL_UNSIGNED_BYTE, pixels);

    glutSwapBuffers();
    glutReshapeWindow(WIDTH, HEIGHT);
    glutPostRedisplay();
}

void display(int *argc, char **argv, int readfd)
{
	glutInit(argc, argv);
	glutInitDisplayMode(GLUT_DOUBLE | GLUT_RGB);
	glutInitWindowSize(69, 69);
	glutCreateWindow(argv[0]);

    fd = readfd;

	glutDisplayFunc(render);
	glutMainLoop();

    puts("DISPLAY EXIT");
}