Example #1
0
static void
loadtiles(void) {
    int lx, rx, ty, by;	/* image bounding box */
    static int ox = TILES*TILESIZE/2, oy = TILES*TILESIZE/2;  /* image origin */
    static int ot = 0, os = 0;
    int dx = 0, dy = 0, nx = -1, ny = -1;
    float trx, try;
#define S_TSIZE	(TSIZE-TILESIZE)	/* visible portion of texture = TSIZE less one tile for slop */

    /* calculate tile #'s at corners of visible region */
    lx = x - S_TSIZE/2;
    rx = lx + S_TSIZE;
    by = y - S_TSIZE/2;
    ty = by + S_TSIZE;
    lx /= TILESIZE; rx /= TILESIZE;
    by /= TILESIZE; ty /= TILESIZE;

    dx = ((x - S_TSIZE/2)/TILESIZE) - ((ox - S_TSIZE/2)/TILESIZE);
    
    nx = lx; ny = by;
    if (dx < 0) {
	/* add on left */
	os -= TILESIZE;
	if (os < 0) os += TSIZE;
	nx = lx;
    } else if (dx > 0) {
	nx = rx;
    }

    dy = ((y - S_TSIZE/2) / TILESIZE) - ((oy - S_TSIZE/2) / TILESIZE);
    if (dy > 0) {
	/* add on bottom */
	ny = ty;
    } else if (dy < 0) {
	/* add on top */
	ot -= TILESIZE;
	if (ot < 0) ot += TSIZE;
	ny = by;
    }
if (dx || dy) printf("dx %d dy %d   lx %d rx %d   by %d ty %d   nx %d ny %d   os %d ot %d\n", dx, dy, lx, rx, by, ty, nx, ny, os, ot);
    if (dx) {
	int t;
	for(t = 0; t < TSIZE; t += TILESIZE) {
	    glTexSubImage2D(GL_TEXTURE_2D, 0, os, (t+ot) % TSIZE, TILESIZE,
                 TILESIZE, GL_RGBA, GL_UNSIGNED_BYTE,
                 tiles[ny+t/TILESIZE][nx].data);
printf("load %d %d  %d %d\n", nx, ny+t/TILESIZE, os, (t+ot) % TSIZE);
	}
    }

    if (dy) {
	int s;
	for(s = 0; s < TSIZE; s += TILESIZE) {
	    glTexSubImage2D(GL_TEXTURE_2D, 0, (s+os) % TSIZE, ot, TILESIZE,
                 TILESIZE, GL_RGBA, GL_UNSIGNED_BYTE,
                 tiles[ny][nx+s/TILESIZE].data);
printf("load %d %d  %d %d\n", nx+s/TILESIZE, ny, (s+os) % TSIZE, ot);
	}
    }
    if (dx > 0) {
	os += TILESIZE;
	if (os >= TSIZE) os -= TSIZE;
    }
    if (dy > 0) {
	ot += TILESIZE;
	if (ot >= TSIZE) ot -= TSIZE;
    }
    ox = x; oy = y;
    glMatrixMode(GL_TEXTURE);
    glLoadIdentity();
    trx = (float)((x-TILES*TILESIZE/2) % TSIZE)/TSIZE;
    try = (float)((y-TILES*TILESIZE/2) % TSIZE)/TSIZE;
    glTranslatef(trx, try, 0.f);
    glMatrixMode(GL_MODELVIEW);
}

static void
init(char *filename) {
    int i;

    mesh0(-1.f,1.f,-1.f,1.f,0.f,1.f,0.f,1.f,0.f,64,64);
    if (filename) {
	image = read_texture(filename, &width, &height, &components);
	if (image == NULL) {
	    fprintf(stderr, "Error: Can't load image file \"%s\".\n",
		    filename);
	    exit(EXIT_FAILURE);
	} else {
	    printf("%d x %d image loaded\n", width, height);
	}
	if (components < 3 || components > 4) {
	    printf("must be RGB or RGBA image\n");
	    exit(EXIT_FAILURE);
	}
    } else {
	int i, j;
	components = 4; width = height = TSIZE;
	image = (unsigned *) malloc(width*height*sizeof(unsigned));
	for (j = 0; j < height; j++)
	    for (i = 0; i < width; i++) {
		if (i & 1)
		    image[i+j*width] = 0xff;
		else
		    image[i+j*width] = 0xff00;
		if (j&1)
		    image[i+j*width] |= 0xff0000;
	    }

    }
    if (width % TILESIZE || height % TILESIZE) {
#define TXSIZE 192
	unsigned *newimage = malloc(TXSIZE*TXSIZE*sizeof *newimage);
	gluScaleImage(GL_RGBA, width, height, GL_UNSIGNED_BYTE, image,
		TXSIZE, TXSIZE, GL_UNSIGNED_BYTE, newimage);
	free(image);
	image = newimage; width = height = TXSIZE; components = 4;
    }
    tile_image(image);
    glPixelStorei(GL_UNPACK_ALIGNMENT, 1);
    glTexEnvf(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_MODULATE);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
    glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_WRAP_S,GL_REPEAT);
    glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_WRAP_T,GL_REPEAT);

    glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, TSIZE,
                 TSIZE, 0, GL_RGBA, GL_UNSIGNED_BYTE, NULL);
    for(i = 0; i < TILES; i++) {
	int j;
	for(j = 0; j < TILES; j++) {
	    glTexSubImage2D(GL_TEXTURE_2D, 0, i*TILESIZE, j*TILESIZE, TILESIZE,
		 TILESIZE, GL_RGBA, GL_UNSIGNED_BYTE, 
		 tiles[(TILES-TSIZE/TILESIZE)/2+j][(TILES-TSIZE/TILESIZE)/2+i].data);
	}
    }
    glEnable(GL_TEXTURE_2D);

    glMatrixMode(GL_PROJECTION);
    glLoadIdentity();
    gluPerspective(90.,1.,.1,10.);
    glMatrixMode(GL_MODELVIEW);
    glLoadIdentity();
    glTranslatef(0.,0.,-1.0);
    glLineWidth(3.0);
    glClearColor(.25, .25, .25, .25);

    /* start at center of image */
    x = TILES*TILESIZE/2;
    y = TILES*TILESIZE/2;
}
Example #2
0
static void
init(char *filename) {
    int i;

    mesh0(-1.f,1.f,-1.f,1.f,0.f,1.f,0.f,1.f,0.f,64,64);
    if (filename) {
	image = read_texture(filename, &width, &height, &components);
	if (image == NULL) {
	    fprintf(stderr, "Error: Can't load image file \"%s\".\n",
		    filename);
	    exit(EXIT_FAILURE);
	} else {
	    printf("%d x %d image loaded\n", width, height);
	}
	if (components < 3 || components > 4) {
	    printf("must be RGB or RGBA image\n");
	    exit(EXIT_FAILURE);
	}
    } else {
	int i, j;
	components = 4; width = height = TSIZE;
	image = (unsigned *) malloc(width*height*sizeof(unsigned));
	for (j = 0; j < height; j++)
	    for (i = 0; i < width; i++) {
		if (i & 1)
		    image[i+j*width] = 0xff;
		else
		    image[i+j*width] = 0xff00;
		if (j&1)
		    image[i+j*width] |= 0xff0000;
	    }

    }
    if (width % TILESIZE || height % TILESIZE) {
#define TXSIZE 192
	unsigned *newimage = malloc(TXSIZE*TXSIZE*sizeof *newimage);
	gluScaleImage(GL_RGBA, width, height, GL_UNSIGNED_BYTE, image,
		TXSIZE, TXSIZE, GL_UNSIGNED_BYTE, newimage);
	free(image);
	image = newimage; width = height = TXSIZE; components = 4;
    }
    tile_image(image);
    glPixelStorei(GL_UNPACK_ALIGNMENT, 1);
    glTexEnvf(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_MODULATE);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
    glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_WRAP_S,GL_REPEAT);
    glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_WRAP_T,GL_REPEAT);

    glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, TSIZE,
                 TSIZE, 0, GL_RGBA, GL_UNSIGNED_BYTE, NULL);
    for(i = 0; i < TILES; i++) {
	int j;
	for(j = 0; j < TILES; j++) {
	    glTexSubImage2D(GL_TEXTURE_2D, 0, i*TILESIZE, j*TILESIZE, TILESIZE,
		 TILESIZE, GL_RGBA, GL_UNSIGNED_BYTE, 
		 tiles[(TILES-TSIZE/TILESIZE)/2+j][(TILES-TSIZE/TILESIZE)/2+i].data);
	}
    }
    glEnable(GL_TEXTURE_2D);

    glMatrixMode(GL_PROJECTION);
    glLoadIdentity();
    gluPerspective(90.,1.,.1,10.);
    glMatrixMode(GL_MODELVIEW);
    glLoadIdentity();
    glTranslatef(0.,0.,-1.0);
    glLineWidth(3.0);
    glClearColor(.25, .25, .25, .25);

    /* start at center of image */
    x = TILES*TILESIZE/2;
    y = TILES*TILESIZE/2;
}