From 0ceb383cd3f24bde6e9855f3b86f161eae3fb14b Mon Sep 17 00:00:00 2001 From: Matthew Hoops Date: Fri, 5 Sep 2014 00:27:22 -0400 Subject: IMAGE: Add a function for generating QuickTime dither tables Much thanks to fuzzie for her assistance. --- image/codecs/codec.cpp | 148 +++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 148 insertions(+) (limited to 'image/codecs/codec.cpp') diff --git a/image/codecs/codec.cpp b/image/codecs/codec.cpp index 6b0c7ebcfb..398e9c562c 100644 --- a/image/codecs/codec.cpp +++ b/image/codecs/codec.cpp @@ -20,6 +20,7 @@ * */ +#include "common/list.h" #include "common/scummsys.h" #include "image/codecs/codec.h" @@ -44,6 +45,153 @@ namespace Image { +namespace { + +/** + * Add a color to the QuickTime dither table check queue if it hasn't already been found. + */ +inline void addColorToQueue(uint16 color, uint16 index, byte *checkBuffer, Common::List &checkQueue) { + if ((READ_UINT16(checkBuffer + color * 2) & 0xFF) == 0) { + // Previously unfound color + WRITE_UINT16(checkBuffer + color * 2, index); + checkQueue.push_back(color); + } +} + +inline byte adjustColorRange(byte currentColor, byte correctColor, byte palColor) { + return CLIP(currentColor - palColor + correctColor, 0, 255); +} + +inline uint16 makeQuickTimeDitherColor(byte r, byte g, byte b) { + // RGB554 + return ((r & 0xF8) << 6) | ((g & 0xF8) << 1) | (b >> 4); +} + +} // End of anonymous namespace + +byte *Codec::createQuickTimeDitherTable(const byte *palette, uint colorCount) { + byte *buf = new byte[0x10000]; + memset(buf, 0, 0x10000); + + Common::List checkQueue; + + bool foundBlack = false; + bool foundWhite = false; + + const byte *palPtr = palette; + + // See what colors we have, and add them to the queue to check + for (uint i = 0; i < colorCount; i++) { + byte r = *palPtr++; + byte g = *palPtr++; + byte b = *palPtr++; + uint16 n = (i << 8) | 1; + uint16 col = makeQuickTimeDitherColor(r, g, b); + + if (col == 0) { + // Special case for close-to-black + // The original did more here, but it effectively discarded the value + // due to a poor if-check (whole 16-bit value instead of lower 8-bits). + WRITE_UINT16(buf, n); + foundBlack = true; + } else if (col == 0x3FFF) { + // Special case for close-to-white + // The original did more here, but it effectively discarded the value + // due to a poor if-check (whole 16-bit value instead of lower 8-bits). + WRITE_UINT16(buf + 0x7FFE, n); + foundWhite = true; + } else { + // Previously unfound color + addColorToQueue(col, n, buf, checkQueue); + } + } + + // More special handling for white + if (foundWhite) + checkQueue.push_front(0x3FFF); + + // More special handling for black + if (foundBlack) + checkQueue.push_front(0); + + // Go through the list of colors we have and match up similar colors + // to fill in the table as best as we can. + while (!checkQueue.empty()) { + uint16 col = checkQueue.front(); + checkQueue.pop_front(); + uint16 index = READ_UINT16(buf + col * 2); + + uint32 x = col << 4; + if ((x & 0xFF) < 0xF0) + addColorToQueue((x + 0x10) >> 4, index, buf, checkQueue); + if ((x & 0xFF) >= 0x10) + addColorToQueue((x - 0x10) >> 4, index, buf, checkQueue); + + uint32 y = col << 7; + if ((y & 0xFF00) < 0xF800) + addColorToQueue((y + 0x800) >> 7, index, buf, checkQueue); + if ((y & 0xFF00) >= 0x800) + addColorToQueue((y - 0x800) >> 7, index, buf, checkQueue); + + uint32 z = col << 2; + if ((z & 0xFF00) < 0xF800) + addColorToQueue((z + 0x800) >> 2, index, buf, checkQueue); + if ((z & 0xFF00) >= 0x800) + addColorToQueue((z - 0x800) >> 2, index, buf, checkQueue); + } + + // Contract the table back to just palette entries + for (int i = 0; i < 0x4000; i++) + buf[i] = READ_UINT16(buf + i * 2) >> 8; + + // Now go through and distribute the error to three more pixels + byte *bufPtr = buf; + for (uint realR = 0; realR < 0x100; realR += 8) { + for (uint realG = 0; realG < 0x100; realG += 8) { + for (uint realB = 0; realB < 0x100; realB += 16) { + byte palIndex = *bufPtr; + byte r = realR; + byte g = realG; + byte b = realB; + + byte palR = palette[palIndex * 3] & 0xF8; + byte palG = palette[palIndex * 3 + 1] & 0xF8; + byte palB = palette[palIndex * 3 + 2] & 0xF0; + + r = adjustColorRange(r, realR, palR); + g = adjustColorRange(g, realG, palG); + b = adjustColorRange(b, realB, palB); + palIndex = buf[makeQuickTimeDitherColor(r, g, b)]; + bufPtr[0x4000] = palIndex; + + palR = palette[palIndex * 3] & 0xF8; + palG = palette[palIndex * 3 + 1] & 0xF8; + palB = palette[palIndex * 3 + 2] & 0xF0; + + r = adjustColorRange(r, realR, palR); + g = adjustColorRange(g, realG, palG); + b = adjustColorRange(b, realB, palB); + palIndex = buf[makeQuickTimeDitherColor(r, g, b)]; + bufPtr[0x8000] = palIndex; + + palR = palette[palIndex * 3] & 0xF8; + palG = palette[palIndex * 3 + 1] & 0xF8; + palB = palette[palIndex * 3 + 2] & 0xF0; + + r = adjustColorRange(r, realR, palR); + g = adjustColorRange(g, realG, palG); + b = adjustColorRange(b, realB, palB); + palIndex = buf[makeQuickTimeDitherColor(r, g, b)]; + bufPtr[0xC000] = palIndex; + + bufPtr++; + } + } + } + + return buf; +} + Codec *createBitmapCodec(uint32 tag, int width, int height, int bitsPerPixel) { switch (tag) { case SWAP_CONSTANT_32(0): -- cgit v1.2.3