void RescaleImage::Get(RGBA *tgt)
{
if(y < 0 || offsets >= vert.End()) {
memset(tgt, 0, sizeof(RGBA) * tsz.cx);
return;
}
offset += *offsets++;
ASSERT(offset >= 0 && offset + segspan <= size.cy);
if(bigseg) {
row_proc(&row_buffers[0 * cx4], GetLine(offset + 0 * step), horz);
row_proc(&row_buffers[1 * cx4], GetLine(offset + 1 * step), horz);
row_proc(&row_buffers[2 * cx4], GetLine(offset + 2 * step), horz);
row_proc(&row_buffers[3 * cx4], GetLine(offset + 3 * step), horz);
BltAASet4Fix(tgt, &row_buffers[0 * cx4], &row_buffers[1 * cx4],
&row_buffers[2 * cx4], &row_buffers[3 * cx4], tsz.cx);
}
else {
int endoff = offset + segment;
for(int next = first + full; next < endoff; next++) {
if(full >= segment)
first++;
else
full++;
row_proc(&row_buffers[next % segment * cx4], GetLine(next), horz);
}
while(first > offset) {
if(full < segment)
full++;
--first;
row_proc(&row_buffers[first % segment * cx4], GetLine(first), horz);
}
ASSERT(offset >= first && endoff <= first + full);
switch(segment) {
case 1:
BltAAFix2(tgt, &row_buffers[offset % segment * cx4], tsz.cx);
offsets++;
break;
case 2:
if(offsets[0] == 0)
BltAAFix2(tgt, &row_buffers[(offset + 1) % segment * cx4], tsz.cx);
else
if(offsets[1] == 0)
BltAAFix2(tgt, &row_buffers[offset % segment * cx4], tsz.cx);
else
BltAASet2Fix(tgt, &row_buffers[(offset + 0) % segment * cx4], offsets[0],
&row_buffers[(offset + 1) % segment * cx4], offsets[1],
tsz.cx);
offsets += 2;
break;
case 3:
BltAASet3Fix(tgt,
&row_buffers[(offset + 0) % segment * cx4], offsets[0],
&row_buffers[(offset + 1) % segment * cx4], offsets[1],
&row_buffers[(offset + 2) % segment * cx4], offsets[2], tsz.cx);
offsets += 3;
break;
default:
NEVER();
break;
}
}
}
bool GReadBitmapFromFile(const char path[], GBitmap* bitmap) {
FILE* file = fopen(path, "rb");
if (NULL == file) {
return always_false();
}
GAutoFClose afc(file);
uint8_t signature[SIGNATURE_BYTES];
if (SIGNATURE_BYTES != fread(signature, 1, SIGNATURE_BYTES, file)) {
return always_false();
}
if (png_sig_cmp(signature, 0, SIGNATURE_BYTES)) {
return always_false();
}
png_structp png_ptr = png_create_read_struct(PNG_LIBPNG_VER_STRING,
NULL, NULL, NULL);
if (NULL == png_ptr) {
return always_false();
}
png_infop info_ptr = png_create_info_struct(png_ptr);
if (NULL == info_ptr) {
png_destroy_read_struct(&png_ptr, NULL, NULL);
return always_false();
}
GAutoPNGReader reader(png_ptr, info_ptr);
if (setjmp(png_jmpbuf(png_ptr))) {
return always_false();
}
png_init_io(png_ptr, file);
png_set_sig_bytes(png_ptr, SIGNATURE_BYTES);
png_read_info(png_ptr, info_ptr);
png_uint_32 width, height;
int bitDepth, colorType;
png_get_IHDR(png_ptr, info_ptr, &width, &height, &bitDepth, &colorType,
NULL, NULL, NULL);
if (8 != bitDepth) {
return always_false(); // TODO: handle other formats
}
if (png_set_interlace_handling(png_ptr) > 1) {
return always_false(); // TODO: support interleave
}
swizzle_row_proc row_proc = NULL;
switch (colorType) {
case PNG_COLOR_TYPE_RGB:
row_proc = swizzle_rgb_row;
break;
case PNG_COLOR_TYPE_RGB_ALPHA:
row_proc = swizzle_rgba_row;
break;
default:
return always_false();
}
png_read_update_info(png_ptr, info_ptr);
GAutoFree rowStorage(malloc(png_get_rowbytes(png_ptr, info_ptr)));
png_bytep srcRow = (png_bytep)rowStorage.get();
if (!srcRow) {
return always_false();
}
GAutoFree pixelStorage(malloc(height * width * 4));
GPixel* dstRow = (GPixel*)pixelStorage.get();
if (NULL == dstRow) {
return always_false();
}
for (int y = 0; y < height; y++) {
uint8_t* tmp = srcRow;
png_read_rows(png_ptr, &tmp, NULL, 1);
row_proc(dstRow, srcRow, width);
dstRow += width;
}
bitmap->fWidth = width;
bitmap->fHeight = height;
bitmap->fRowBytes = width * 4;
bitmap->fPixels = (GPixel*)pixelStorage.detach();
return true;
}
