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Diffstat (limited to 'graphics/colormasks.h')
| -rw-r--r-- | graphics/colormasks.h | 221 |
1 files changed, 221 insertions, 0 deletions
diff --git a/graphics/colormasks.h b/graphics/colormasks.h new file mode 100644 index 0000000000..422af23d85 --- /dev/null +++ b/graphics/colormasks.h @@ -0,0 +1,221 @@ +/* ScummVM - Scumm Interpreter + * Copyright (C) 2001 Ludvig Strigeus + * Copyright (C) 2001-2006 The ScummVM project + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; either version 2 + * of the License, or (at your option) any later version. + + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. + * + * $URL$ + * $Id$ + * + */ + +#ifndef GRAPHICS_COLORMASKS_H +#define GRAPHICS_COLORMASKS_H + +template<int bitFormat> +struct ColorMasks { +}; + +/* +The ColorMasks template can be used to map bit format values +(like 555, 565, 1555, 4444) to corresponding bit masks and shift values. +Currently this is only meant for + +The meaning of these is masks is the following: + kBytesPerPixel + -> how many bytes per pixel for that format + + kRedMask, kGreenMask, kBlueMask + -> bitmask, and this with the color to select only the bits of the corresponding color + + The k*Bits and k*Shift values can be used to extract R,G,B. I.e. to get + the red color component of a pixel, as a 8-bit value, you would write + + R = ((color & kRedMask) >> kRedShift) << (8-kRedBits) + + Actually, instead of the simple left shift, one might want to use somewhat + more sophisticated code (which fills up the lower most bits. + + + The highBits / lowBits / qhighBits / qlowBits are special values that are + used in the super-optimized interpolation functions in scaler/intern.h + and scaler/aspect.cpp. Currently they are only available in 555 and 565 mode. + To be specific: They pack the masks for two 16 bit pixels at once. The pixels + are split into "high" and "low" bits, which are then separately interpolated + and finally re-composed. That way, 2x2 pixels or even 4x2 pixels can + be interpolated in one go. + +*/ + + +template<> +struct ColorMasks<565> { + enum { + highBits = 0xF7DEF7DE, + lowBits = 0x08210821, + qhighBits = 0xE79CE79C, + qlowBits = 0x18631863, + + + kBytesPerPixel = 2, + + kAlphaBits = 0, + kRedBits = 5, + kGreenBits = 6, + kBlueBits = 5, + + kAlphaShift = kRedBits+kGreenBits+kBlueBits, + kRedShift = kGreenBits+kBlueBits, + kGreenShift = kBlueBits, + kBlueShift = 0, + + kAlphaMask = ((1 << kAlphaBits) - 1) << kAlphaShift, + kRedMask = ((1 << kRedBits) - 1) << kRedShift, + kGreenMask = ((1 << kGreenBits) - 1) << kGreenShift, + kBlueMask = ((1 << kBlueBits) - 1) << kBlueShift, + + kRedBlueMask = kRedMask | kBlueMask + + }; +}; + +template<> +struct ColorMasks<555> { + enum { + highBits = 0x7BDE7BDE, + lowBits = 0x04210421, + qhighBits = 0x739C739C, + qlowBits = 0x0C630C63, + + + kBytesPerPixel = 2, + + kAlphaBits = 0, + kRedBits = 5, + kGreenBits = 5, + kBlueBits = 5, + + kAlphaShift = kRedBits+kGreenBits+kBlueBits, + kRedShift = kGreenBits+kBlueBits, + kGreenShift = kBlueBits, + kBlueShift = 0, + + kAlphaMask = ((1 << kAlphaBits) - 1) << kAlphaShift, + kRedMask = ((1 << kRedBits) - 1) << kRedShift, + kGreenMask = ((1 << kGreenBits) - 1) << kGreenShift, + kBlueMask = ((1 << kBlueBits) - 1) << kBlueShift, + + kRedBlueMask = kRedMask | kBlueMask + }; +}; + +template<> +struct ColorMasks<1555> { + enum { + kBytesPerPixel = 2, + + kAlphaBits = 1, + kRedBits = 5, + kGreenBits = 5, + kBlueBits = 5, + + kAlphaShift = kRedBits+kGreenBits+kBlueBits, + kRedShift = kGreenBits+kBlueBits, + kGreenShift = kBlueBits, + kBlueShift = 0, + + kAlphaMask = ((1 << kAlphaBits) - 1) << kAlphaShift, + kRedMask = ((1 << kRedBits) - 1) << kRedShift, + kGreenMask = ((1 << kGreenBits) - 1) << kGreenShift, + kBlueMask = ((1 << kBlueBits) - 1) << kBlueShift, + + kRedBlueMask = kRedMask | kBlueMask + }; +}; + +template<> +struct ColorMasks<4444> { + enum { + kBytesPerPixel = 2, + + kAlphaBits = 4, + kRedBits = 4, + kGreenBits = 4, + kBlueBits = 4, + + kAlphaShift = kRedBits+kGreenBits+kBlueBits, + kRedShift = kGreenBits+kBlueBits, + kGreenShift = kBlueBits, + kBlueShift = 0, + + kAlphaMask = ((1 << kAlphaBits) - 1) << kAlphaShift, + kRedMask = ((1 << kRedBits) - 1) << kRedShift, + kGreenMask = ((1 << kGreenBits) - 1) << kGreenShift, + kBlueMask = ((1 << kBlueBits) - 1) << kBlueShift, + + kRedBlueMask = kRedMask | kBlueMask + }; +}; + +template<> +struct ColorMasks<888> { + enum { + kBytesPerPixel = 4, + + kAlphaBits = 0, + kRedBits = 8, + kGreenBits = 8, + kBlueBits = 8, + + kAlphaShift = kRedBits+kGreenBits+kBlueBits, + kRedShift = kGreenBits+kBlueBits, + kGreenShift = kBlueBits, + kBlueShift = 0, + + kAlphaMask = ((1 << kAlphaBits) - 1) << kAlphaShift, + kRedMask = ((1 << kRedBits) - 1) << kRedShift, + kGreenMask = ((1 << kGreenBits) - 1) << kGreenShift, + kBlueMask = ((1 << kBlueBits) - 1) << kBlueShift, + + kRedBlueMask = kRedMask | kBlueMask + }; +}; + +template<> +struct ColorMasks<8888> { + enum { + kBytesPerPixel = 4, + + kAlphaBits = 8, + kRedBits = 8, + kGreenBits = 8, + kBlueBits = 8, + + kAlphaShift = kRedBits+kGreenBits+kBlueBits, + kRedShift = kGreenBits+kBlueBits, + kGreenShift = kBlueBits, + kBlueShift = 0, + + kAlphaMask = ((1 << kAlphaBits) - 1) << kAlphaShift, + kRedMask = ((1 << kRedBits) - 1) << kRedShift, + kGreenMask = ((1 << kGreenBits) - 1) << kGreenShift, + kBlueMask = ((1 << kBlueBits) - 1) << kBlueShift, + + kRedBlueMask = kRedMask | kBlueMask + }; +}; + + +#endif |