/* ScummVM - Scumm Interpreter * Copyright (C) 2001 Ludvig Strigeus * Copyright (C) 2001-2003 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., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. * * $Header$ * */ #include "common/scaler/intern.h" #include "common/scaler.h" #define kVeryFastAndUglyAspectMode 0 // No interpolation at all, but super-fast #define kFastAndNiceAspectMode 1 // Quite good quality with good speed #define kSlowAndPerfectAspectMode 2 // Accurate but slow code #define ASPECT_MODE kFastAndNiceAspectMode #if ASPECT_MODE == kSlowAndPerfectAspectMode template static inline uint16 interpolate5(uint16 A, uint16 B) { uint16 r = (uint16)(((A & redblueMask & 0xFF00) * scale + (B & redblueMask & 0xFF00) * (5 - scale)) / 5); uint16 g = (uint16)(((A & greenMask) * scale + (B & greenMask) * (5 - scale)) / 5); uint16 b = (uint16)(((A & redblueMask & 0x00FF) * scale + (B & redblueMask & 0x00FF) * (5 - scale)) / 5); return (uint16)((r & redblueMask & 0xFF00) | (g & greenMask) | (b & redblueMask & 0x00FF)); } template static inline void interpolate5Line(uint16 *dst, const uint16 *srcA, const uint16 *srcB, int width) { // Accurate but slightly slower code while (width--) { *dst++ = interpolate5(*srcA++, *srcB++); } } #endif #if ASPECT_MODE == kFastAndNiceAspectMode template static inline uint32 INTERPOLATE_1_1(uint32 A, uint32 B) { return (((A & highBits) >> 1) + ((B & highBits) >> 1) + (A & B & lowBits)); } template static inline uint32 INTERPOLATE_1_3(uint32 A, uint32 B) { register uint32 x = ((A & qhighBits) >> 2) + ((B & qhighBits) >> 2) * 3; register uint32 y = ((A & qlowBits) + (B & qlowBits) * 3) >> 2; y &= qlowBits; return x + y; } template static inline void interpolate5Line(uint16 *dst, const uint16 *srcA, const uint16 *srcB, int width) { // For efficiency reasons we blit two pixels at a time, so it is important // that makeRectStretchable() guarantees that the width is even and that // the rect starts on a well-aligned address. (Even where unaligned memory // access is allowed there may be a speed penalty for it.) // These asserts are disabled for maximal speed; but I leave them in here // in case other people want to test if the memory alignment (to an // address divisible by 4) is really working properly. //assert(((int)dst & 3) == 0); //assert(((int)srcA & 3) == 0); //assert(((int)srcB & 3) == 0); //assert((width & 1) == 0); width /= 2; const uint32 *sA = (const uint32 *)srcA; const uint32 *sB = (const uint32 *)srcB; uint32 *d = (uint32 *)dst; if (scale == 1) { while (width--) { *d++ = INTERPOLATE_1_3(*sA++, *sB++); } } else { while (width--) { *d++ = INTERPOLATE_1_1(*sA++, *sB++); } } } #endif void makeRectStretchable(int &x, int &y, int &w, int &h) { #if ASPECT_MODE != kVeryFastAndUglyAspectMode int m = real2Aspect(y) % 6; // Ensure that the rect will start on a line that won't have its // colours changed by the stretching function. if (m != 0 && m != 5) { y -= m; h += m; } #if ASPECT_MODE == kFastAndNiceAspectMode // Force x to be even, to ensure aligned memory access (this assumes // that each line starts at an even memory location, but that should // be the case on every target anyway). if (x & 1) { x--; w++; } // Finally force the width to be even, since we blit 2 pixels at a time. // While this means we may sometimes blit one column more than necessary, // this should actually be faster than having the check for the if (w & 1) w++; #endif #endif } /** * Stretch a 16bpp image vertically by factor 1.2. Used to correct the * aspect-ratio in games using 320x200 pixel graphics with non-qudratic * pixels. Applying this method effectively turns that into 320x240, which * provides the correct aspect-ratio on modern displays. * * The image would normally have occupied y coordinates origSrcY through * origSrcY + height - 1. * * However, we have already placed it at srcY - the aspect-corrected y * coordinate - to allow in-place stretching. * * Therefore, the source image now occupies Y coordinates srcY through * srcY + height - 1, and it should be stretched to Y coordinates srcY * through real2Aspect(srcY + height - 1). */ template int stretch200To240(uint8 *buf, uint32 pitch, int width, int height, int srcX, int srcY, int origSrcY) { int maxDstY = real2Aspect(origSrcY + height - 1); int y; const uint8 *startSrcPtr = buf + srcX * 2 + (srcY - origSrcY) * pitch; uint8 *dstPtr = buf + srcX * 2 + maxDstY * pitch; for (y = maxDstY; y >= srcY; y--) { const uint8 *srcPtr = startSrcPtr + aspect2Real(y) * pitch; #if ASPECT_MODE == kVeryFastAndUglyAspectMode if (srcPtr == dstPtr) break; memcpy(dstPtr, srcPtr, width * 2); #else // Bilinear filter switch (y % 6) { case 0: case 5: if (srcPtr != dstPtr) memcpy(dstPtr, srcPtr, width * 2); break; case 1: interpolate5Line((uint16 *)dstPtr, (const uint16 *)(srcPtr - pitch), (const uint16 *)srcPtr, width); break; case 2: interpolate5Line((uint16 *)dstPtr, (const uint16 *)(srcPtr - pitch), (const uint16 *)srcPtr, width); break; case 3: interpolate5Line((uint16 *)dstPtr, (const uint16 *)srcPtr, (const uint16 *)(srcPtr - pitch), width); break; case 4: interpolate5Line((uint16 *)dstPtr, (const uint16 *)srcPtr, (const uint16 *)(srcPtr - pitch), width); break; } #endif dstPtr -= pitch; } return 1 + maxDstY - srcY; } int stretch200To240(uint8 *buf, uint32 pitch, int width, int height, int srcX, int srcY, int origSrcY) { if (gBitFormat == 565) return stretch200To240<565>(buf, pitch, width, height, srcX, srcY, origSrcY); else // gBitFormat == 555 return stretch200To240<555>(buf, pitch, width, height, srcX, srcY, origSrcY); }