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Diffstat (limited to 'graphics/scaler/downscaler.cpp')
-rw-r--r-- | graphics/scaler/downscaler.cpp | 96 |
1 files changed, 96 insertions, 0 deletions
diff --git a/graphics/scaler/downscaler.cpp b/graphics/scaler/downscaler.cpp new file mode 100644 index 0000000000..21ba1ce36d --- /dev/null +++ b/graphics/scaler/downscaler.cpp @@ -0,0 +1,96 @@ +/* ScummVM - Graphic Adventure Engine + * + * ScummVM is the legal property of its developers, whose names + * are too numerous to list here. Please refer to the COPYRIGHT + * file distributed with this source distribution. + * + * 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. + * + * $URL$ + * $Id$ + * + */ +#include "graphics/scaler/downscaler.h" +#include "graphics/scaler/intern.h" + +#ifdef ARM +extern "C" { + void DownscaleAllByHalfARM(const uint8 *srcPtr, uint32 srcPitch, uint8 *dstPtr, uint32 dstPitch, int width, int height, int mask, int round); +} + +void DownscaleAllByHalf(const uint8 *srcPtr, uint32 srcPitch, uint8 *dstPtr, uint32 dstPitch, int width, int height) { + // Rounding constants and masks used for different pixel formats + static const int roundingconstants[] = { 0x00200802, 0x00201002 }; + static const int redbluegreenMasks[] = { 0x03E07C1F, 0x07E0F81F }; + + const int maskUsed = (gBitFormat == 565); + DownscaleAllByHalfARM(srcPtr, srcPitch, dstPtr, dstPitch, width, height, redbluegreenMasks[maskUsed], roundingconstants[maskUsed]); +} + +#else + +template<int bitFormat> +void DownscaleAllByHalfTemplate(const uint8 *srcPtr, uint32 srcPitch, uint8 *dstPtr, uint32 dstPitch, int width, int height) { + uint8 *work; + uint16 srcPitch16 = (uint16)(srcPitch / sizeof(uint16)); + + while ((height -= 2) >= 0) { + work = dstPtr; + + for (int i=0; i<width; i+=2) { + // Another lame filter attempt :) + uint16 color1 = *(((const uint16 *)srcPtr) + i); + uint16 color2 = *(((const uint16 *)srcPtr) + (i + 1)); + uint16 color3 = *(((const uint16 *)srcPtr) + (i + srcPitch16)); + uint16 color4 = *(((const uint16 *)srcPtr) + (i + srcPitch16 + 1)); + *(((uint16 *)work) + 0) = interpolate16_1_1_1_1<Graphics::ColorMasks<bitFormat> >(color1, color2, color3, color4); + + work += sizeof(uint16); + } + srcPtr += 2 * srcPitch; + dstPtr += dstPitch; + } +} +MAKE_WRAPPER(DownscaleAllByHalf) + +#endif + + +/** + * This filter (down)scales the source image horizontally by a factor of 1/2. + * For example, a 320x200 image is scaled to 160x200. + */ +template<int bitFormat> +void DownscaleHorizByHalfTemplate(const uint8 *srcPtr, uint32 srcPitch, uint8 *dstPtr, uint32 dstPitch, int width, int height) { + uint16 *work; + + if (!height) + return; + + // Various casts below go via (void *) to avoid warning. This is + // safe as these are all even addresses. + while (height--) { + work = (uint16 *)(void *)dstPtr; + + for (int i = 0; i < width; i += 2) { + uint16 color1 = *(((const uint16 *)(const void *)srcPtr) + i); + uint16 color2 = *(((const uint16 *)(const void *)srcPtr) + (i + 1)); + *work++ = interpolate32_1_1<bitFormat>(color1, color2); + } + srcPtr += srcPitch; + dstPtr += dstPitch; + } +} +MAKE_WRAPPER(DownscaleHorizByHalf) |