scummvm/graphics/scaler/downscaler.cpp

146 lines
5.5 KiB
C++

/* 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.
*
*/
#include "graphics/scaler/downscaler.h"
#include "graphics/scaler/intern.h"
#ifdef USE_ARM_SCALER_ASM
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 };
extern int gBitFormat;
const int maskUsed = (gBitFormat == 565);
DownscaleAllByHalfARM(srcPtr, srcPitch, dstPtr, dstPitch, width, height, redbluegreenMasks[maskUsed], roundingconstants[maskUsed]);
}
#else
template<typename ColorMask>
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<ColorMask>(color1, color2, color3, color4);
work += sizeof(uint16);
}
srcPtr += 2 * srcPitch;
dstPtr += dstPitch;
}
}
void DownscaleAllByHalf(const uint8 *srcPtr, uint32 srcPitch, uint8 *dstPtr, uint32 dstPitch, int width, int height) {
extern int gBitFormat;
if (gBitFormat == 565)
DownscaleAllByHalfTemplate<Graphics::ColorMasks<565> >(srcPtr, srcPitch, dstPtr, dstPitch, width, height);
else
DownscaleAllByHalfTemplate<Graphics::ColorMasks<555> >(srcPtr, srcPitch, dstPtr, dstPitch, width, height);
}
#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<typename ColorMask>
void DownscaleHorizByHalfTemplate(const uint8 *srcPtr, uint32 srcPitch, uint8 *dstPtr, uint32 dstPitch, int width, int height) {
uint16 *work;
// 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<ColorMask>(color1, color2);
}
srcPtr += srcPitch;
dstPtr += dstPitch;
}
}
void DownscaleHorizByHalf(const uint8 *srcPtr, uint32 srcPitch, uint8 *dstPtr, uint32 dstPitch, int width, int height) {
extern int gBitFormat;
if (gBitFormat == 565)
DownscaleHorizByHalfTemplate<Graphics::ColorMasks<565> >(srcPtr, srcPitch, dstPtr, dstPitch, width, height);
else
DownscaleHorizByHalfTemplate<Graphics::ColorMasks<555> >(srcPtr, srcPitch, dstPtr, dstPitch, width, height);
}
/**
* This filter (down)scales the source image horizontally by a factor of 3/4.
* For example, a 320x200 image is scaled to 240x200.
*/
template<typename ColorMask>
void DownscaleHorizByThreeQuartersTemplate(const uint8 *srcPtr, uint32 srcPitch, uint8 *dstPtr, uint32 dstPitch, int width, int height) {
uint16 *work;
// 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 += 4) {
// Work with 4 pixels
uint16 color1 = *(((const uint16 *)(const void *)srcPtr) + i);
uint16 color2 = *(((const uint16 *)(const void *)srcPtr) + (i + 1));
uint16 color3 = *(((const uint16 *)(const void *)srcPtr) + (i + 2));
uint16 color4 = *(((const uint16 *)(const void *)srcPtr) + (i + 3));
work[0] = interpolate32_3_1<ColorMask>(color1, color2);
work[1] = interpolate32_1_1<ColorMask>(color2, color3);
work[2] = interpolate32_3_1<ColorMask>(color4, color3);
work += 3;
}
srcPtr += srcPitch;
dstPtr += dstPitch;
}
}
void DownscaleHorizByThreeQuarters(const uint8 *srcPtr, uint32 srcPitch, uint8 *dstPtr, uint32 dstPitch, int width, int height) {
extern int gBitFormat;
if (gBitFormat == 565)
DownscaleHorizByThreeQuartersTemplate<Graphics::ColorMasks<565> >(srcPtr, srcPitch, dstPtr, dstPitch, width, height);
else
DownscaleHorizByThreeQuartersTemplate<Graphics::ColorMasks<555> >(srcPtr, srcPitch, dstPtr, dstPitch, width, height);
}