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| author | Eugene Sandulenko | 2016-05-04 22:53:46 +0200 |
|---|---|---|
| committer | Eugene Sandulenko | 2016-05-04 22:53:46 +0200 |
| commit | b8f288873bbcd54e7a984ccd9ae56e82e78aa631 (patch) | |
| tree | 9aac40f1f54fa0244a539d52c138f31ba4ef4f33 /engines/scumm | |
| parent | 5cfbb176e793797d1345429f88d7efe4b733f98e (diff) | |
| download | scummvm-rg350-b8f288873bbcd54e7a984ccd9ae56e82e78aa631.tar.gz scummvm-rg350-b8f288873bbcd54e7a984ccd9ae56e82e78aa631.tar.bz2 scummvm-rg350-b8f288873bbcd54e7a984ccd9ae56e82e78aa631.zip | |
SCUMM HE: Fix premultiplied T14 calculation
We were hitting integer overflow which lead to shadow artifacts.
Diffstat (limited to 'engines/scumm')
| -rw-r--r-- | engines/scumm/he/moonbase/moonbase.cpp | 11 |
1 files changed, 6 insertions, 5 deletions
diff --git a/engines/scumm/he/moonbase/moonbase.cpp b/engines/scumm/he/moonbase/moonbase.cpp index b6bfd4515e..1f9d843bb9 100644 --- a/engines/scumm/he/moonbase/moonbase.cpp +++ b/engines/scumm/he/moonbase/moonbase.cpp @@ -118,13 +118,13 @@ void Moonbase::blitT14WizImage(uint8 *dst, int dstw, int dsth, int dstPitch, con if (pixels >= sx) { int alpha = code >> 1; uint16 color = READ_LE_UINT16(singlesOffset); + uint32 orig = READ_LE_UINT16(dst1); //WRITE_LE_UINT16(dst1, color); // ENABLE_PREMUL_ALPHA = 0 // ENABLE_PREMUL_ALPHA = 2 if (alpha > 32) { alpha -= 32; - uint32 orig = READ_LE_UINT16(dst1); uint32 oR = orig & 0x7c00; uint32 oG = orig & 0x03e0; uint32 oB = orig & 0x1f; @@ -134,10 +134,11 @@ void Moonbase::blitT14WizImage(uint8 *dst, int dstw, int dsth, int dstPitch, con WRITE_LE_UINT16(dst1, (dR & 0x7c00) | (dG & 0x3e0) | (dB & 0x1f)); } else { - uint32 orig = READ_LE_UINT16(dst1); - uint32 pass1 = ((((orig << 16) | orig) & 0x3e07c1f * alpha) >> 5) & 0x3e07c1f; - uint32 pass2 = (((pass1 << 16) | pass1) + color) & 0xffff; - WRITE_LE_UINT16(dst1, pass2); + uint32 pix = ((orig << 16) | orig) & 0x3e07c1f; + pix = (((pix * alpha) & 0xffffffff) >> 5) & 0x3e07c1f; + pix = ((pix << 16) + pix + color) & 0xffff; + + WRITE_LE_UINT16(dst1, pix); } dst1 += 2; |