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Fix blit_rgba_to_rgba: converting channels that were at least 1bpp

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to a higher bit depth resulted in 0s.  This caused banners to be transparent
on Macs.  This also fixes scaling: scale colors instead of truncating them.
This is a little slower; I might need to add an optimized blit for the d3d movie
code path ...
This commit is contained in:
Glenn Maynard
2004-09-05 22:18:14 +00:00
parent abc76e28ed
commit 174810d286
1 changed files with 45 additions and 18 deletions
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stepmania/src/RageSurfaceUtils.cpp
+45 -18
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@@ -516,29 +516,58 @@ static void blit_rgba_to_rgba( const RageSurface *src_surf, const RageSurface *d
RageSurfaceUtils::GetBitsPerChannel(src_surf->format, src_bits);
RageSurfaceUtils::GetBitsPerChannel(dst_surf->format, dst_bits);
const int rshifts[4] = {
src_surf->format->Rshift + src_bits[0] - dst_bits[0],
src_surf->format->Gshift + src_bits[1] - dst_bits[1],
src_surf->format->Bshift + src_bits[2] - dst_bits[2],
src_surf->format->Ashift + src_bits[3] - dst_bits[3],
/* XXX: We should store the shifts and masks as an array in RageSurfaceFormat. */
const int src_shifts[4] = {
src_surf->format->Rshift,
src_surf->format->Gshift,
src_surf->format->Bshift,
src_surf->format->Ashift,
};
const int lshifts[4] = {
const int dst_shifts[4] = {
dst_surf->format->Rshift,
dst_surf->format->Gshift,
dst_surf->format->Bshift,
dst_surf->format->Ashift,
};
const uint32_t masks[4] = {
const uint32_t src_masks[4] =
{
src_surf->format->Rmask,
src_surf->format->Gmask,
src_surf->format->Bmask,
src_surf->format->Amask
};
int ormask = 0;
if( src_surf->format->Amask == 0 )
ormask = dst_surf->format->Amask;
const uint32_t dst_masks[4] =
{
dst_surf->format->Rmask,
dst_surf->format->Gmask,
dst_surf->format->Bmask,
dst_surf->format->Amask
};
uint8_t lookup[4][256];
for( int c = 0; c < 4; ++c )
{
const uint32_t max_src_val = src_masks[c] >> src_shifts[c];
const uint32_t max_dst_val = dst_masks[c] >> dst_shifts[c];
ASSERT( max_src_val <= 0xFF );
ASSERT( max_dst_val <= 0xFF );
if( src_masks[c] == 0 )
{
/* The source is missing a channel. Alpha defaults to opaque, other
* channels default to 0. */
if( c == 3 )
lookup[c][0] = (uint8_t) max_dst_val;
else
lookup[c][0] = 0;
} else {
for( uint32_t i = 0; i <= max_src_val; ++i )
lookup[c][i] = (uint8_t) SCALE( i, 0, max_src_val, 0, max_dst_val );
}
}
while( height-- )
{
@@ -547,15 +576,13 @@ static void blit_rgba_to_rgba( const RageSurface *src_surf, const RageSurface *d
{
unsigned int pixel = RageSurfaceUtils::decodepixel( src, src_surf->format->BytesPerPixel );
/* Convert pixel to the destination RGBA. */
/* Convert pixel to the destination format. */
unsigned int opixel = 0;
opixel |= (pixel & masks[0]) >> rshifts[0] << lshifts[0];
opixel |= (pixel & masks[1]) >> rshifts[1] << lshifts[1];
opixel |= (pixel & masks[2]) >> rshifts[2] << lshifts[2];
opixel |= (pixel & masks[3]) >> rshifts[3] << lshifts[3];
// Correct surfaces that don't have an alpha channel.
opixel |= ormask;
for( int c = 0; c < 4; ++c )
{
int src = (pixel & src_masks[c]) >> src_shifts[c];
opixel |= lookup[c][src] << dst_shifts[c];
}
/* Store it. */
RageSurfaceUtils::encodepixel( dst, dst_surf->format->BytesPerPixel, opixel );