diff options
Diffstat (limited to 'common/scaler.cpp')
| -rw-r--r-- | common/scaler.cpp | 102 |
1 files changed, 99 insertions, 3 deletions
diff --git a/common/scaler.cpp b/common/scaler.cpp index 1607fef214..0d952110c1 100644 --- a/common/scaler.cpp +++ b/common/scaler.cpp @@ -30,7 +30,9 @@ static uint32 lowPixelMask = 0x08210821; static uint32 qcolorMask = 0xE79CE79C; static uint32 qlowpixelMask = 0x18631863; static uint32 redblueMask = 0xF81F; -static uint32 greenMask = 0x7E0; +static uint32 redMask = 0xF800; +static uint32 greenMask = 0x07E0; +static uint32 blueMask = 0x001F; static const uint16 dotmatrix_565[16] = { 0x01E0, 0x0007, 0x3800, 0x0000, @@ -53,7 +55,9 @@ int Init_2xSaI(uint32 BitFormat) { qcolorMask = 0xE79CE79C; qlowpixelMask = 0x18631863; redblueMask = 0xF81F; - greenMask = 0x7E0; + redMask = 0xF800; + greenMask = 0x07E0; + blueMask = 0x001F; dotmatrix = dotmatrix_565; } else if (BitFormat == 555) { colorMask = 0x7BDE7BDE; @@ -61,7 +65,9 @@ int Init_2xSaI(uint32 BitFormat) { qcolorMask = 0x739C739C; qlowpixelMask = 0x0C630C63; redblueMask = 0x7C1F; - greenMask = 0x3E0; + redMask = 0x7C00; + greenMask = 0x03E0; + blueMask = 0x001F; dotmatrix = dotmatrix_555; } else { return 0; @@ -634,3 +640,93 @@ void DotMatrix(const uint8 *srcPtr, uint32 srcPitch, uint8 *dstPtr, uint32 dstPi q += nextlineDst << 1; } } + + +static inline uint32 interpolate5(uint16 A, uint16 B, int scale) { + uint16 r = ((A & redMask) * scale + (B & redMask) * (5 - scale)) / 5; + uint16 g = ((A & greenMask) * scale + (B & greenMask) * (5 - scale)) / 5; + uint16 b = ((A & blueMask) * scale + (B & blueMask) * (5 - scale)) / 5; + + return (r & redMask) | (g & greenMask) | (b & blueMask); +} + +static inline void interpolate5Line(uint16 *dst, const uint16 *srcA, const uint16 *srcB, int scale, int width) { +#if 1 + // Accurate but slightly slower code + while (width--) { + *dst++ = interpolate5(*srcA++, *srcB++, scale); + } +#else + // Not fully accurate, but a bit faster + width /= 2; + const uint32 *sA = (const uint32 *)srcA; + const uint32 *sB = (const uint32 *)srcB; + uint32 *d = (uint32 *)dst; + if (scale == 1) { + while (width--) { + uint32 B = *sB++; + *d++ = Q_INTERPOLATE(*sA++, B, B, B); + } + } else { + while (width--) { + *d++ = INTERPOLATE(*sA++, *sB++); + } + } +#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). + */ +int stretch200To240(uint8 *buf, uint32 pitch, int width, int height, int srcX, int srcY, int origSrcY) { + int maxDstY = real2Aspect(origSrcY + height - 1); + int off = srcY - origSrcY; + int y; + + uint8 *dstPtr = buf + srcX * 2 + maxDstY * pitch; + + for (y = maxDstY; y >= srcY; y--) { + uint8 *srcPtr = buf + srcX * 2 + (aspect2Real(y) + off) * pitch; + + if (srcPtr == dstPtr) + break; + +#if 0 + // Don't use bilinear filtering, rather just duplicate pixel lines: + // a little bit faster, but looks ugly + memcpy(dstPtr, srcPtr, width * 2); +#else + // Bilinear filter + switch (y % 6) { + case 0: + case 5: + memcpy(dstPtr, srcPtr, width * 2); + break; + case 1: + case 4: + interpolate5Line((uint16 *)dstPtr, (uint16 *)(srcPtr - pitch), (uint16 *)srcPtr, 1, width); + break; + case 2: + case 3: + interpolate5Line((uint16 *)dstPtr, (uint16 *)(srcPtr - pitch), (uint16 *)srcPtr, 2, width); + break; + } +#endif + dstPtr -= pitch; + } + + return 1 + maxDstY - srcY; +} |