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;
}
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;
}