#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
//#include <unistd.h>
#include "tk.h"


GLenum doubleBuffer, directRender;
GLint windW, windH;

char *fileName = 0;
TK_RGBImageRec *image;
float point[3];
float zoom;
GLint x, y;


static void Init(void)
{

    glClearColor(0.0, 0.0, 0.0, 0.0);

    x = 0;
    y = windH;
    zoom = 1.8;
}

static void Reshape(int width, int height)
{

    windW = (GLint)width;
    windH = (GLint)height;

    glViewport(0, 0, windW, windH);

    glMatrixMode(GL_PROJECTION);
    glLoadIdentity();
    gluOrtho2D(0.,(float) windW, 0., (float)windH);
    glMatrixMode(GL_MODELVIEW);
}

static GLenum Key(int key, GLenum mask)
{

    switch (key) {
      case TK_B:
	tkClipBoard();
	break;
      case TK_ESCAPE:
        tkQuit();
      case TK_Z:
	zoom += 0.2;
	break;
      case TK_z:
	zoom -= 0.2;
	if (zoom < 0.2) {
	    zoom = 0.2;
	}
	break;
      default:
	return GL_FALSE;
    }
    return GL_TRUE;
}

static GLenum Mouse(int mouseX, int mouseY, GLenum button)
{

    x = (GLint)mouseX;
    y = (GLint)mouseY;
    return GL_TRUE;
}

static void Draw(void)
{

    glClear(GL_COLOR_BUFFER_BIT);

    point[0] = (windW / 2) - (image->sizeX / 2);
    point[1] = (windH / 2) - (image->sizeY / 2);
    point[2] = 0;
    glRasterPos3fv(point);

    glPixelStorei(GL_UNPACK_ALIGNMENT, 1);
    glPixelZoom(1.0, 1.0);
    glDrawPixels(image->sizeX, image->sizeY, GL_RGB, GL_UNSIGNED_BYTE,
		 image->data);

    point[0] = (float)x;
    point[1] = windH - (float)y;
    point[2] = 0.0;
    glRasterPos3fv(point);

    glPixelZoom(zoom, zoom);
    glCopyPixels((windW/2)-(image->sizeX/2),
		 (windH/2)-(image->sizeY/2),
		 image->sizeX, image->sizeY, GL_COLOR);

    glFlush();

    if (doubleBuffer) {
	tkSwapBuffers();
    }
}

static GLenum Args(int argc, char **argv)
{
    GLint i;

    doubleBuffer = GL_FALSE;
    directRender = GL_TRUE;

    for (i = 1; i < argc; i++) {
	if (strcmp(argv[i], "-sb") == 0) {
	    doubleBuffer = GL_FALSE;
	} else if (strcmp(argv[i], "-db") == 0) {
	    doubleBuffer = GL_TRUE;
	} else if (strcmp(argv[i], "-dr") == 0) {
	    directRender = GL_TRUE;
	} else if (strcmp(argv[i], "-ir") == 0) {
	    directRender = GL_FALSE;
	} else if (strcmp(argv[i], "-f") == 0) {
	    if (i+1 >= argc || argv[i+1][0] == '-') {
		printf("-f (No file name).\n");
		return GL_FALSE;
	    } else {
		fileName = argv[++i];
	    }
	} else {
	    printf("%s (Bad option).\n", argv[i]);
	    return GL_FALSE;
	}
    }
    return GL_TRUE;
}

void main(int argc, char **argv)
{
    GLenum type;

    if (Args(argc, argv) == GL_FALSE) {
	tkQuit();
    }

    if (fileName == 0) {
	printf("No image file.\n");
	tkQuit();
    }

    image = tkRGBImageLoad(fileName);

    windW = 300;
    windH = 300;
    tkInitPosition(0, 0, windW, windH);

    type = TK_RGB;
    type |= (doubleBuffer) ? TK_DOUBLE : TK_SINGLE;
    type |= (directRender) ? TK_DIRECT : TK_INDIRECT;
    tkInitDisplayMode(type);

    if (tkInitWindow("Copy Test") == GL_FALSE) {
	tkQuit();
    }

    Init();

    tkExposeFunc(Reshape);
    tkReshapeFunc(Reshape);
    tkKeyDownFunc(Key);
    tkMouseDownFunc(Mouse);
    tkDisplayFunc(Draw);
    tkExec();
}
