/* ---------------------------------------------------------------------------
* Return a pointer to a given pixel. Accounts for image orientation (T_TO_B,
* R_TO_L, etc). Returns NULL if the pixel is out of range.
*/
uint8_t *tga_find_pixel(const tga_image *img, uint16_t x, uint16_t y)
{
if (x >= img->width || y >= img->height)
return NULL;
if (!tga_is_top_to_bottom(img)) y = img->height - 1 - y;
if (tga_is_right_to_left(img)) x = img->width - 1 - x;
return img->image_data + (x + y * img->width) * img->pixel_depth/8;
}
void load_tga(tga_image *tga, const char *fn)
{
DONTFAIL( tga_read(tga, fn) );
printf("Loaded %dx%dx%dbpp targa (\"%s\").\n",
tga->width, tga->height, tga->pixel_depth, fn);
if (!tga_is_mono(tga)) DONTFAIL( tga_desaturate_rec_601_1(tga) );
if (!tga_is_top_to_bottom(tga)) DONTFAIL( tga_flip_vert(tga) );
if (tga_is_right_to_left(tga)) DONTFAIL( tga_flip_horiz(tga) );
if ((tga->width % 8 != 0) || (tga->height % 8 != 0))
{
printf("Width and height must be multiples of 8\n");
exit(EXIT_FAILURE);
}
}
/* ---------------------------------------------------------------------------
* Vertically flip the image in place. Reverses the top-to-bottom bit in
* the image descriptor.
*/
tga_result tga_flip_vert(tga_image *img)
{
uint16_t col;
size_t bpp, line;
uint8_t *top, *bottom;
int t_to_b;
if (!SANE_DEPTH(img->pixel_depth)) return TGAERR_PIXEL_DEPTH;
bpp = (size_t)(img->pixel_depth / 8); /* bytes per pixel */
line = bpp * img->width; /* bytes per line */
for (col=0; col<img->width; col++)
{
top = img->image_data + col * bpp;
bottom = top + (img->height - 1) * line;
/* reverse from top to bottom */
while (top < bottom)
{
uint8_t buffer[4];
/* swap */
memcpy(buffer, top, bpp);
memcpy(top, bottom, bpp);
memcpy(bottom, buffer, bpp);
top += line;
bottom -= line;
}
}
/* Correct image_descriptor's top-to-bottom-ness. */
t_to_b = tga_is_top_to_bottom(img);
img->image_descriptor &= ~TGA_T_TO_B_BIT; /* mask out t-to-b bit */
if (!t_to_b)
/* was b-to-t, need to set t_to_b */
img->image_descriptor |= TGA_T_TO_B_BIT;
/* else bit is already rubbed out */
return TGA_NOERR;
}
static RGBSpectrum *ReadImageTGA(const std::string &name, int *width,
int *height) {
tga_image img;
tga_result result;
if ((result = tga_read(&img, name.c_str())) != TGA_NOERR) {
Error("Unable to read from TGA file \"%s\" (%s)", name.c_str(),
tga_error(result));
return nullptr;
}
if (tga_is_right_to_left(&img)) tga_flip_horiz(&img);
if (!tga_is_top_to_bottom(&img)) tga_flip_vert(&img);
if (tga_is_colormapped(&img)) tga_color_unmap(&img);
*width = img.width;
*height = img.height;
// "Unpack" the pixels (origin in the lower left corner).
// TGA pixels are in BGRA format.
RGBSpectrum *ret = new RGBSpectrum[*width * *height];
RGBSpectrum *dst = ret;
for (int y = *height - 1; y >= 0; y--)
for (int x = 0; x < *width; x++) {
uint8_t *src = tga_find_pixel(&img, x, y);
if (tga_is_mono(&img))
*dst++ = RGBSpectrum(*src / 255.f);
else {
Float c[3];
c[2] = src[0] / 255.f;
c[1] = src[1] / 255.f;
c[0] = src[2] / 255.f;
*dst++ = RGBSpectrum::FromRGB(c);
}
}
tga_free_buffers(&img);
Info("Read TGA image %s (%d x %d)", name.c_str(), *width, *height);
return ret;
}
void ImageFormat_TGA::CopyPixels(unsigned int* destination)
{
tga_image* image=static_cast<tga_image*>(image_);
bool upsidedown=!tga_is_top_to_bottom(image);
int width=image->width;
int height=image->height;
unsigned char* data=image->image_data;
if (image->pixel_depth==24)
{
for (int y=0; y<height; y++)
{
for (int x=0; x<width; x++)
{
unsigned int c=0xff000000;
c|=data[2]<<16;
c|=data[1]<<8;
c|=data[0];
int yp=y;
if (upsidedown)
{
yp=height-y-1;
}
destination[x+yp*width]=c;
data+=3;
}
}
return;
}
if (image->pixel_depth==32)
{
for (int y=0; y<height; y++)
{
for (int x=0; x<width; x++)
{
unsigned int c=0x00000000;
c|=data[3]<<24;
c|=data[2]<<16;
c|=data[1]<<8;
c|=data[0];
int yp=y;
if (upsidedown)
{
yp=height-y-1;
}
destination[x+yp*width]=c;
data+=4;
}
}
return;
}
if (image->pixel_depth==16)
{
for (int y=0; y<height; y++)
{
for (int x=0; x<width; x++)
{
unsigned int s=data[1]<<8 | data[0];
unsigned int c=0xff000000;
unsigned int b=((s&0x1f));
unsigned int g=(((s>>5)&0x1f));
unsigned int r=(((s>>10)&0x1f));
float fr=((float)r)/31.0f;
float fg=((float)g)/31.0f;
float fb=((float)b)/31.0f;
r=(unsigned int)(255.0f*fr);
g=(unsigned int)(255.0f*fg);
b=(unsigned int)(255.0f*fb);
c|=r<<16;
c|=g<<8;
c|=b;
int yp=y;
if (upsidedown)
{
yp=height-y-1;
}
destination[x+yp*width]=c;
data+=2;
}
}
return;
}
Assert(false,"Unsupported TGA file");
}
