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944 lines
35 KiB
944 lines
35 KiB
/******************************Module*Header*******************************\
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* Module Name: dither.cxx
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*
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* This algorithm for color dithering is patent pending and its use is
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* restricted to Microsoft products and drivers for Microsoft products.
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* Use in non-Microsoft products or in drivers for non-Microsoft products
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* is prohibited without the expressed written consent of Microsoft Corp.
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*
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* The patent application is the primary reference for the operation of the
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* color dithering code.
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*
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* Note that in the comments and variable names, "vertex" means "vertex of
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* either the inner (half intensity) or outer (full intensity) color cube."
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* Vertices map to colors 0-7 and 9-15 of the Windows standard (required)
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* 16-color palette, where vertices 0-7 are the vertices of the inner color
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* cube, and 0 plus 9-15 are the vertices of the full color cube. Vertex 8 is
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* 75% gray; this could be used in the dither, but that would break apps that
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* depend on the exact Windows 3.1 dithering. This code is Window 3.1
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* compatible.
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*
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* Note that as a result of the compatibility requirement, the dither
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* produced by this algorithm is the exact same dither as that produced
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* by the default Windows 3.1 16 color and 256 color VGA drivers.
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*
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* Copyright (c) 1992-1999 Microsoft Corporation
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\**************************************************************************/
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#include "precomp.hxx"
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/**************************************************************************\
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* This function takes a value from 0 - 255 and uses it to create an
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* 8x8 pile of bits in the form of a 1BPP bitmap. It can also take an
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* RGB value and make an 8x8 bitmap. These can then be used as brushes
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* to simulate color unavaible on the device.
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*
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* For monochrome the basic algorithm is equivalent to turning on bits
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* in the 8x8 array according to the following order:
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*
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* 00 32 08 40 02 34 10 42
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* 48 16 56 24 50 18 58 26
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* 12 44 04 36 14 46 06 38
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* 60 28 52 20 62 30 54 22
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* 03 35 11 43 01 33 09 41
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* 51 19 59 27 49 17 57 25
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* 15 47 07 39 13 45 05 37
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* 63 31 55 23 61 29 53 21
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*
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* Reference: A Survey of Techniques for the Display of Continous
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* Tone Pictures on Bilevel Displays,;
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* Jarvis, Judice, & Ninke;
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* COMPUTER GRAPHICS AND IMAGE PROCESSING 5, pp 13-40, (1976)
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\**************************************************************************/
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#define SWAP_RB 0x00000004
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#define SWAP_GB 0x00000002
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#define SWAP_RG 0x00000001
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#define SWAPTHEM(a,b) (ulTemp = a, a = b, b = ulTemp)
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// PATTERNSIZE is the number of pixels in a dither pattern.
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#define PATTERNSIZE 64
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// Tells which row to turn a pel on in when dithering for monochrome bitmaps.
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static BYTE ajByte[] = {
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0, 4, 0, 4, 2, 6, 2, 6,
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0, 4, 0, 4, 2, 6, 2, 6,
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1, 5, 1, 5, 3, 7, 3, 7,
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1, 5, 1, 5, 3, 7, 3, 7,
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0, 4, 0, 4, 2, 6, 2, 6,
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0, 4, 0, 4, 2, 6, 2, 6,
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1, 5, 1, 5, 3, 7, 3, 7,
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1, 5, 1, 5, 3, 7, 3, 7
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};
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// The array of monochrome bits used for monc
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static BYTE ajBits[] = {
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0x80, 0x08, 0x08, 0x80, 0x20, 0x02, 0x02, 0x20,
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0x20, 0x02, 0x02, 0x20, 0x80, 0x08, 0x08, 0x80,
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0x40, 0x04, 0x04, 0x40, 0x10, 0x01, 0x01, 0x10,
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0x10, 0x01, 0x01, 0x10, 0x40, 0x04, 0x04, 0x40,
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0x40, 0x04, 0x04, 0x40, 0x10, 0x01, 0x01, 0x10,
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0x10, 0x01, 0x01, 0x10, 0x40, 0x04, 0x04, 0x40,
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0x80, 0x08, 0x08, 0x80, 0x20, 0x02, 0x02, 0x20,
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0x20, 0x02, 0x02, 0x20, 0x80, 0x08, 0x08, 0x80
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};
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// Translates vertices back to the original subspace. Each row is a subspace,
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// as encoded in ulSymmetry, and each column is a vertex between 0 and 15.
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BYTE jSwapSubSpace[8*16] = {
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0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15,
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0, 2, 1, 3, 4, 6, 5, 7, 8, 10, 9, 11, 12, 14, 13, 15,
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0, 1, 4, 5, 2, 3, 6, 7, 8, 9, 12, 13, 10, 11, 14, 15,
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0, 4, 1, 5, 2, 6, 3, 7, 8, 12, 9, 13, 10, 14, 11, 15,
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0, 4, 2, 6, 1, 5, 3, 7, 8, 12, 10, 14, 9, 13, 11, 15,
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0, 2, 4, 6, 1, 3, 5, 7, 8, 10, 12, 14, 9, 11, 13, 15,
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0, 4, 1, 5, 2, 6, 3, 7, 8, 12, 9, 13, 10, 14, 11, 15,
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0, 1, 4, 5, 2, 3, 6, 7, 8, 9, 12, 13, 10, 11, 14, 15,
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};
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// Converts a nibble value in the range 0-15 to a dword value containing the
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// nibble value packed 8 times.
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// For 8bpp, also translate to 256-color palette index.
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ULONG ulNibbleTo8bppDword[16] = {
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0x00000000,
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0x01010101,
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0x02020202,
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0x03030303,
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0x04040404,
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0x05050505,
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0x06060606,
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0xF8F8F8F8,
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0x07070707,
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0xF9F9F9F9,
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0xFAFAFAFA,
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0xFBFBFBFB,
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0xFCFCFCFC,
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0xFDFDFDFD,
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0xFEFEFEFE,
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0xFFFFFFFF
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};
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// For 4bpp, no translation is necessary.
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ULONG ulNibbleTo4bppDword[16] = {
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0x00000000,
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0x01010101,
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0x02020202,
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0x03030303,
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0x04040404,
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0x05050505,
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0x06060606,
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0x07070707,
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0x08080808,
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0x09090909,
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0x0A0A0A0A,
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0x0B0B0B0B,
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0x0C0C0C0C,
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0x0D0D0D0D,
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0x0E0E0E0E,
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0x0F0F0F0F
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};
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// Specifies where in the dither pattern colors should be placed in order
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// of increasing intensity.
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// 8bpp specific version.
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ULONG aulDither8bppOrder[] = {
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0, 36, 4, 32, 18, 54, 22, 50,
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2, 38, 6, 34, 16, 52, 20, 48,
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9, 45, 13, 41, 27, 63, 31, 59,
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11, 47, 15, 43, 25, 61, 29, 57,
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1, 37, 5, 33, 19, 55, 23, 51,
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3, 39, 7, 35, 17, 53, 21, 49,
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8, 44, 12, 40, 26, 62, 30, 58,
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10, 46, 14, 42, 24, 60, 28, 56,
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};
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// 4bpp specific version. This is organized in the following form, for
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// efficiency: every set of 8 pixels (0-7, 8-15, 16-23, ... ,56-63) is
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// placed in the dither pattern in the order: 0 2 4 6 1 3 5 7. This is
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// done so that two longs can be combined to put 8 pixels in DIB4 format
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// at once (the first dword is shifted left 4, then the two dwords are
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// ORed, to produce 0 1 2 3 4 5 6 7 order in memory), which is much faster than
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// combining the output of the straight dither ordering.
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// The effective dither ordering after we combine each pair of ULONGS at the
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// end (the desired dither ordering) matches aulDither8bppOrder (see above).
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//
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ULONG aulDither4bppOrder[] = {
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0, 34, 2, 32, 17, 51, 19, 49,
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1, 35, 3, 33, 16, 50, 18, 48,
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12, 46, 14, 44, 29, 63, 31, 61,
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13, 47, 15, 45, 28, 62, 30, 60,
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4, 38, 6, 36, 21, 55, 23, 53,
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5, 39, 7, 37, 20, 54, 22, 52,
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8, 42, 10, 40, 25, 59, 27, 57,
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9, 43, 11, 41, 24, 58, 26, 56,
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};
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// Array to convert to 256 color from 16 color. Maps from index that represents
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// a 16-color vertex (color) to value that specifies the color index in the
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// 256-color palette.
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BYTE ajConvert[] =
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{
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0,
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1,
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2,
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3,
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4,
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5,
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6,
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248,
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7,
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249,
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250,
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251,
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252,
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253,
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254,
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255
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};
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// Describes a single colour tetrahedron vertex for dithering:
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typedef struct _VERTEX_DATA {
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ULONG ulCount; // Number of pixels in this vertex
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ULONG ulVertex; // Vertex number
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} VERTEX_DATA; /* vd, pv */
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VERTEX_DATA* vComputeSubspaces(ULONG, VERTEX_DATA*);
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VOID vDitherColor8bpp(ULONG*, VERTEX_DATA*, VERTEX_DATA*, ULONG);
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VOID vDitherColor4bpp(ULONG*, VERTEX_DATA*, VERTEX_DATA*, ULONG);
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/******************************Public*Routine******************************\
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* vComputeSubspaces
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*
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* Calculates the subspace data associated with rgb, stores the data at
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* pvVertexData, in the form of an array of VERTEX_DATA structures,
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* suitable for vDitherColor. Returns a pointer to the byte after the
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* last VERTEX_DATA structure.
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*
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* Ignores the high byte of rgb.
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*
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\**************************************************************************/
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VERTEX_DATA* vComputeSubspaces(
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ULONG rgb,
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VERTEX_DATA* pvVertexData)
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{
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ULONG ulRedTemp, ulGreenTemp, ulBlueTemp, ulSymmetry;
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ULONG ulRed, ulGre, ulBlu, ulTemp;
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ULONG ulVertex0Temp, ulVertex1Temp, ulVertex2Temp, ulVertex3Temp;
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// Split the color into red, green, and blue components
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ulRedTemp = ((PAL_ULONG *)&rgb)->pal.peRed;
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ulGreenTemp = ((PAL_ULONG *)&rgb)->pal.peGreen;
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ulBlueTemp = ((PAL_ULONG *)&rgb)->pal.peBlue;
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// Sort the RGB so that the point is transformed into subspace 0, and
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// keep track of the swaps in ulSymmetry so we can unravel it again
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// later. We want r >= g >= b (subspace 0).
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ulSymmetry = 0;
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if (ulBlueTemp > ulRedTemp) {
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SWAPTHEM(ulBlueTemp,ulRedTemp);
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ulSymmetry = SWAP_RB;
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}
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if (ulBlueTemp > ulGreenTemp) {
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SWAPTHEM(ulBlueTemp,ulGreenTemp);
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ulSymmetry |= SWAP_GB;
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}
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if (ulGreenTemp > ulRedTemp) {
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SWAPTHEM(ulGreenTemp,ulRedTemp);
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ulSymmetry |= SWAP_RG;
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}
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ulSymmetry <<= 4; // for lookup purposes
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// Scale the values from 0-255 to 0-64. Note that the scaling is not
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// symmetric at the ends; this is done to match Windows 3.1 dithering
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ulRed = (ulRedTemp + 1) >> 2;
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ulGre = (ulGreenTemp + 1) >> 2;
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ulBlu = (ulBlueTemp + 1) >> 2;
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// Compute the subsubspace within subspace 0 in which the point lies,
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// then calculate the # of pixels to dither in the colors that are the
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// four vertexes of the tetrahedron bounding the color we're emulating.
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// Only vertices with more than zero pixels are stored, and the
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// vertices are stored in order of increasing intensity, saving us the
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// need to sort them later
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if ((ulRedTemp + ulGreenTemp) > 256) {
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// Subsubspace 2 or 3
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if ((ulRedTemp + ulBlueTemp) > 256) {
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// Subsubspace 3
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// Calculate the number of pixels per vertex, still in
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// subsubspace 3, then convert to original subspace. The pixel
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// counts and vertex numbers are matching pairs, stored in
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// ascending intensity order, skipping vertices with zero
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// pixels. The vertex intensity order for subsubspace 3 is:
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// 7, 9, 0x0B, 0x0F
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if ((ulVertex0Temp = (64 - ulRed) << 1) != 0) {
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pvVertexData->ulCount = ulVertex0Temp;
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pvVertexData++->ulVertex = jSwapSubSpace[ulSymmetry + 0x07];
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}
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ulVertex2Temp = ulGre - ulBlu;
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ulVertex3Temp = (ulRed - 64) + ulBlu;
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if ((ulVertex1Temp = ((PATTERNSIZE - ulVertex0Temp) -
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ulVertex2Temp) - ulVertex3Temp) != 0) {
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pvVertexData->ulCount = ulVertex1Temp;
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pvVertexData++->ulVertex = jSwapSubSpace[ulSymmetry + 0x09];
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}
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if (ulVertex2Temp != 0) {
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pvVertexData->ulCount = ulVertex2Temp;
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pvVertexData++->ulVertex = jSwapSubSpace[ulSymmetry + 0x0B];
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}
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if (ulVertex3Temp != 0) {
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pvVertexData->ulCount = ulVertex3Temp;
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pvVertexData++->ulVertex = jSwapSubSpace[ulSymmetry + 0x0F];
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}
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} else {
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// Subsubspace 2
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// Calculate the number of pixels per vertex, still in
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// subsubspace 2, then convert to original subspace. The pixel
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// counts and vertex numbers are matching pairs, stored in
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// ascending intensity order, skipping vertices with zero
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// pixels. The vertex intensity order for subsubspace 2 is:
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// 3, 7, 9, 0x0B
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ulVertex1Temp = ulBlu << 1;
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ulVertex2Temp = ulRed - ulGre;
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ulVertex3Temp = (ulRed - 32) + (ulGre - 32);
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if ((ulVertex0Temp = ((PATTERNSIZE - ulVertex1Temp) -
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ulVertex2Temp) - ulVertex3Temp) != 0) {
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pvVertexData->ulCount = ulVertex0Temp;
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pvVertexData++->ulVertex = jSwapSubSpace[ulSymmetry + 0x03];
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}
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if (ulVertex1Temp != 0) {
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pvVertexData->ulCount = ulVertex1Temp;
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pvVertexData++->ulVertex = jSwapSubSpace[ulSymmetry + 0x07];
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}
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if (ulVertex2Temp != 0) {
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pvVertexData->ulCount = ulVertex2Temp;
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pvVertexData++->ulVertex = jSwapSubSpace[ulSymmetry + 0x09];
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}
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if (ulVertex3Temp != 0) {
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pvVertexData->ulCount = ulVertex3Temp;
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pvVertexData++->ulVertex = jSwapSubSpace[ulSymmetry + 0x0B];
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}
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}
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} else {
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// Subsubspace 0 or 1
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if (ulRedTemp > 128) {
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// Subsubspace 1
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// Calculate the number of pixels per vertex, still in
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// subsubspace 1, then convert to original subspace. The pixel
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// counts and vertex numbers are matching pairs, stored in
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// ascending intensity order, skipping vertices with zero
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// pixels. The vertex intensity order for subsubspace 1 is:
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// 1, 3, 7, 9
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if ((ulVertex0Temp = ((32 - ulGre) + (32 - ulRed)) << 1) != 0) {
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pvVertexData->ulCount = ulVertex0Temp;
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pvVertexData++->ulVertex = jSwapSubSpace[ulSymmetry + 0x01];
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}
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ulVertex2Temp = ulBlu << 1;
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ulVertex3Temp = (ulRed - 32) << 1;
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if ((ulVertex1Temp = ((PATTERNSIZE - ulVertex0Temp) -
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ulVertex2Temp) - ulVertex3Temp) != 0) {
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pvVertexData->ulCount = ulVertex1Temp;
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pvVertexData++->ulVertex = jSwapSubSpace[ulSymmetry + 0x03];
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}
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if (ulVertex2Temp != 0) {
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pvVertexData->ulCount = ulVertex2Temp;
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pvVertexData++->ulVertex = jSwapSubSpace[ulSymmetry + 0x07];
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}
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if (ulVertex3Temp != 0) {
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pvVertexData->ulCount = ulVertex3Temp;
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pvVertexData++->ulVertex = jSwapSubSpace[ulSymmetry + 0x09];
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}
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} else {
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// Subsubspace 0
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// Calculate the number of pixels per vertex, still in
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// subsubspace 0, then convert to original subspace. The pixel
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// counts and vertex numbers are matching pairs, stored in
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// ascending intensity order, skipping vertices with zero
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// pixels. The vertex intensity order for subsubspace 0 is:
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// 0, 1, 3, 7
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if ((ulVertex0Temp = (32 - ulRed) << 1) != 0) {
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pvVertexData->ulCount = ulVertex0Temp;
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pvVertexData++->ulVertex = jSwapSubSpace[ulSymmetry + 0x00];
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}
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if ((ulVertex1Temp = (ulRed - ulGre) << 1) != 0) {
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pvVertexData->ulCount = ulVertex1Temp;
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pvVertexData++->ulVertex = jSwapSubSpace[ulSymmetry + 0x01];
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}
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ulVertex3Temp = ulBlu << 1;
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if ((ulVertex2Temp = ((PATTERNSIZE - ulVertex0Temp) -
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ulVertex1Temp) - ulVertex3Temp) != 0) {
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pvVertexData->ulCount = ulVertex2Temp;
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pvVertexData++->ulVertex = jSwapSubSpace[ulSymmetry + 0x03];
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}
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if (ulVertex3Temp != 0) {
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pvVertexData->ulCount = ulVertex3Temp;
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pvVertexData++->ulVertex = jSwapSubSpace[ulSymmetry + 0x07];
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}
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}
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}
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return(pvVertexData);
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}
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/******************************Public*Routine******************************\
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* vDitherColor8bpp
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*
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* Dithers the ulNumVertices vertices described by vVertexData into pulDest.
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*
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\**************************************************************************/
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VOID vDitherColor8bpp(
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ULONG* pulDest,
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VERTEX_DATA* vVertexData,
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VERTEX_DATA* pvVertexDataEnd,
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ULONG ulNumVertices)
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{
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ULONG ulTemp, ulNumPixels, ulColor;
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VERTEX_DATA *pvMaxVertex, *pvVertexData;
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ULONG *pulDitherOrder;
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BYTE jColor;
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BYTE *pjDither = (BYTE *)pulDest;
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if (ulNumVertices > 2) {
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// There are 3 or 4 vertices in this dither
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if (ulNumVertices == 3) {
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// There are 3 vertices in this dither
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// Find the vertex with the most pixels, and fill the whole
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|
// destination bitmap with that vertex's color, which is faster
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// than dithering it
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if (vVertexData[1].ulCount >= vVertexData[2].ulCount) {
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pvMaxVertex = &vVertexData[1];
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ulTemp = vVertexData[1].ulCount;
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} else {
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pvMaxVertex = &vVertexData[2];
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ulTemp = vVertexData[2].ulCount;
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}
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} else {
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// There are 4 vertices in this dither
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// Find the vertex with the most pixels, and fill the whole
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// destination bitmap with that vertex's color, which is faster
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// than dithering it
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if (vVertexData[2].ulCount >= vVertexData[3].ulCount) {
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pvMaxVertex = &vVertexData[2];
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ulTemp = vVertexData[2].ulCount;
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} else {
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pvMaxVertex = &vVertexData[3];
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ulTemp = vVertexData[3].ulCount;
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}
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|
}
|
|
|
|
if (vVertexData[1].ulCount > ulTemp) {
|
|
pvMaxVertex = &vVertexData[1];
|
|
ulTemp = vVertexData[1].ulCount;
|
|
}
|
|
if (vVertexData[0].ulCount > ulTemp) {
|
|
pvMaxVertex = &vVertexData[0];
|
|
}
|
|
|
|
// Prepare a dword version of the most common vertex number (color)
|
|
ulColor = ulNibbleTo8bppDword[pvMaxVertex->ulVertex];
|
|
|
|
// Mark that the vertex we're about to do doesn't need to be done
|
|
// later
|
|
pvMaxVertex->ulVertex = 0xFF;
|
|
|
|
// Block fill the dither pattern with the more common vertex
|
|
*pulDest = ulColor;
|
|
*(pulDest+1) = ulColor;
|
|
*(pulDest+2) = ulColor;
|
|
*(pulDest+3) = ulColor;
|
|
*(pulDest+4) = ulColor;
|
|
*(pulDest+5) = ulColor;
|
|
*(pulDest+6) = ulColor;
|
|
*(pulDest+7) = ulColor;
|
|
*(pulDest+8) = ulColor;
|
|
*(pulDest+9) = ulColor;
|
|
*(pulDest+10) = ulColor;
|
|
*(pulDest+11) = ulColor;
|
|
*(pulDest+12) = ulColor;
|
|
*(pulDest+13) = ulColor;
|
|
*(pulDest+14) = ulColor;
|
|
*(pulDest+15) = ulColor;
|
|
|
|
// Now dither all the remaining vertices in order 0->2 or 0->3
|
|
// (in order of increasing intensity)
|
|
pulDitherOrder = aulDither8bppOrder;
|
|
pvVertexData = vVertexData;
|
|
do {
|
|
if (pvVertexData->ulVertex == 0xFF) {
|
|
// This is the max vertex, which we already did, but we
|
|
// have to account for it in the dither order
|
|
pulDitherOrder += pvVertexData->ulCount;
|
|
} else {
|
|
jColor = (BYTE) ajConvert[pvVertexData->ulVertex];
|
|
ulNumPixels = pvVertexData->ulCount;
|
|
switch (ulNumPixels & 3) {
|
|
case 3:
|
|
pjDither[*(pulDitherOrder+2)] = jColor;
|
|
case 2:
|
|
pjDither[*(pulDitherOrder+1)] = jColor;
|
|
case 1:
|
|
pjDither[*(pulDitherOrder+0)] = jColor;
|
|
pulDitherOrder += ulNumPixels & 3;
|
|
case 0:
|
|
break;
|
|
}
|
|
if ((ulNumPixels >>= 2) != 0) {
|
|
do {
|
|
pjDither[*pulDitherOrder] = jColor;
|
|
pjDither[*(pulDitherOrder+1)] = jColor;
|
|
pjDither[*(pulDitherOrder+2)] = jColor;
|
|
pjDither[*(pulDitherOrder+3)] = jColor;
|
|
pulDitherOrder += 4;
|
|
} while (--ulNumPixels);
|
|
}
|
|
}
|
|
} while (++pvVertexData < pvVertexDataEnd);
|
|
|
|
} else if (ulNumVertices == 2) {
|
|
|
|
// There are exactly two vertices with more than zero pixels; fill
|
|
// in the dither array as follows: block fill with vertex with more
|
|
// points first, then dither in the other vertex
|
|
if (vVertexData[0].ulCount >= vVertexData[1].ulCount) {
|
|
// There are no more vertex 1 than vertex 0 pixels, so do
|
|
// the block fill with vertex 0
|
|
ulColor = ulNibbleTo8bppDword[vVertexData[0].ulVertex];
|
|
// Do the dither with vertex 1
|
|
jColor = (BYTE) ajConvert[vVertexData[1].ulVertex];
|
|
ulNumPixels = vVertexData[1].ulCount;
|
|
// Set where to start dithering with vertex 1 (vertex 0 is
|
|
// lower intensity, so its pixels come first in the dither
|
|
// order)
|
|
pulDitherOrder = aulDither8bppOrder + vVertexData[0].ulCount;
|
|
} else {
|
|
// There are more vertex 1 pixels, so do the block fill
|
|
// with vertex 1
|
|
ulColor = ulNibbleTo8bppDword[vVertexData[1].ulVertex];
|
|
// Do the dither with vertex 0
|
|
jColor = (BYTE) ajConvert[vVertexData[0].ulVertex];
|
|
ulNumPixels = vVertexData[0].ulCount;
|
|
// Set where to start dithering with vertex 0 (vertex 0 is
|
|
// lower intensity, so its pixels come first in the dither
|
|
// order)
|
|
pulDitherOrder = aulDither8bppOrder;
|
|
}
|
|
|
|
// Block fill the dither pattern with the more common vertex
|
|
*pulDest = ulColor;
|
|
*(pulDest+1) = ulColor;
|
|
*(pulDest+2) = ulColor;
|
|
*(pulDest+3) = ulColor;
|
|
*(pulDest+4) = ulColor;
|
|
*(pulDest+5) = ulColor;
|
|
*(pulDest+6) = ulColor;
|
|
*(pulDest+7) = ulColor;
|
|
*(pulDest+8) = ulColor;
|
|
*(pulDest+9) = ulColor;
|
|
*(pulDest+10) = ulColor;
|
|
*(pulDest+11) = ulColor;
|
|
*(pulDest+12) = ulColor;
|
|
*(pulDest+13) = ulColor;
|
|
*(pulDest+14) = ulColor;
|
|
*(pulDest+15) = ulColor;
|
|
|
|
// Dither in the less common vertex
|
|
switch (ulNumPixels & 3) {
|
|
case 3:
|
|
pjDither[*(pulDitherOrder+2)] = jColor;
|
|
case 2:
|
|
pjDither[*(pulDitherOrder+1)] = jColor;
|
|
case 1:
|
|
pjDither[*(pulDitherOrder+0)] = jColor;
|
|
pulDitherOrder += ulNumPixels & 3;
|
|
case 0:
|
|
break;
|
|
}
|
|
if ((ulNumPixels >>= 2) != 0) {
|
|
do {
|
|
pjDither[*pulDitherOrder] = jColor;
|
|
pjDither[*(pulDitherOrder+1)] = jColor;
|
|
pjDither[*(pulDitherOrder+2)] = jColor;
|
|
pjDither[*(pulDitherOrder+3)] = jColor;
|
|
pulDitherOrder += 4;
|
|
} while (--ulNumPixels);
|
|
}
|
|
|
|
} else {
|
|
|
|
// There is only one vertex in this dither
|
|
|
|
// No sorting or dithering is needed for just one color; we can
|
|
// just generate the final DIB directly
|
|
ulColor = ulNibbleTo8bppDword[vVertexData[0].ulVertex];
|
|
*pulDest = ulColor;
|
|
*(pulDest+1) = ulColor;
|
|
*(pulDest+2) = ulColor;
|
|
*(pulDest+3) = ulColor;
|
|
*(pulDest+4) = ulColor;
|
|
*(pulDest+5) = ulColor;
|
|
*(pulDest+6) = ulColor;
|
|
*(pulDest+7) = ulColor;
|
|
*(pulDest+8) = ulColor;
|
|
*(pulDest+9) = ulColor;
|
|
*(pulDest+10) = ulColor;
|
|
*(pulDest+11) = ulColor;
|
|
*(pulDest+12) = ulColor;
|
|
*(pulDest+13) = ulColor;
|
|
*(pulDest+14) = ulColor;
|
|
*(pulDest+15) = ulColor;
|
|
}
|
|
}
|
|
|
|
|
|
/******************************Public*Routine******************************\
|
|
* vDitherColor4bpp
|
|
*
|
|
* Dithers the ulNumVertices vertices described by vVertexData into pulDest.
|
|
*
|
|
\**************************************************************************/
|
|
|
|
VOID vDitherColor4bpp(
|
|
ULONG * pulDest,
|
|
VERTEX_DATA * vVertexData,
|
|
VERTEX_DATA * pvVertexDataEnd,
|
|
ULONG ulNumVertices)
|
|
{
|
|
ULONG ulTemp, ulNumPixels, ulColor;
|
|
VERTEX_DATA *pvMaxVertex, *pvVertexData;
|
|
ULONG *pulTemp, *pulDitherOrder;
|
|
BYTE jColor;
|
|
BYTE ajDither[64];
|
|
|
|
if (ulNumVertices > 2) {
|
|
|
|
// There are 3 or 4 vertices in this dither
|
|
if (ulNumVertices == 3) {
|
|
|
|
// There are 3 vertices in this dither
|
|
|
|
// Find the vertex with the most pixels, and fill the whole
|
|
// destination bitmap with that vertex's color, which is faster
|
|
// than dithering it
|
|
if (vVertexData[1].ulCount >= vVertexData[2].ulCount) {
|
|
pvMaxVertex = &vVertexData[1];
|
|
ulTemp = vVertexData[1].ulCount;
|
|
} else {
|
|
pvMaxVertex = &vVertexData[2];
|
|
ulTemp = vVertexData[2].ulCount;
|
|
}
|
|
|
|
} else {
|
|
|
|
// There are 4 vertices in this dither
|
|
|
|
// Find the vertex with the most pixels, and fill the whole
|
|
// destination bitmap with that vertex's color, which is faster
|
|
// than dithering it
|
|
if (vVertexData[2].ulCount >= vVertexData[3].ulCount) {
|
|
pvMaxVertex = &vVertexData[2];
|
|
ulTemp = vVertexData[2].ulCount;
|
|
} else {
|
|
pvMaxVertex = &vVertexData[3];
|
|
ulTemp = vVertexData[3].ulCount;
|
|
}
|
|
}
|
|
|
|
if (vVertexData[1].ulCount > ulTemp) {
|
|
pvMaxVertex = &vVertexData[1];
|
|
ulTemp = vVertexData[1].ulCount;
|
|
}
|
|
if (vVertexData[0].ulCount > ulTemp) {
|
|
pvMaxVertex = &vVertexData[0];
|
|
}
|
|
|
|
// Prepare a dword version of the most common vertex number (color)
|
|
ulColor = ulNibbleTo4bppDword[pvMaxVertex->ulVertex];
|
|
|
|
// Mark that the vertex we're about to do doesn't need to be done
|
|
// later
|
|
pvMaxVertex->ulVertex = 0xFF;
|
|
|
|
// Block fill the dither pattern with the more common vertex
|
|
pulTemp = (ULONG *)ajDither;
|
|
*pulTemp = ulColor;
|
|
*(pulTemp+1) = ulColor;
|
|
*(pulTemp+2) = ulColor;
|
|
*(pulTemp+3) = ulColor;
|
|
*(pulTemp+4) = ulColor;
|
|
*(pulTemp+5) = ulColor;
|
|
*(pulTemp+6) = ulColor;
|
|
*(pulTemp+7) = ulColor;
|
|
*(pulTemp+8) = ulColor;
|
|
*(pulTemp+9) = ulColor;
|
|
*(pulTemp+10) = ulColor;
|
|
*(pulTemp+11) = ulColor;
|
|
*(pulTemp+12) = ulColor;
|
|
*(pulTemp+13) = ulColor;
|
|
*(pulTemp+14) = ulColor;
|
|
*(pulTemp+15) = ulColor;
|
|
|
|
// Now dither all the remaining vertices in order 0->2 or 0->3
|
|
// (in order of increasing intensity)
|
|
pulDitherOrder = aulDither4bppOrder;
|
|
pvVertexData = vVertexData;
|
|
do {
|
|
if (pvVertexData->ulVertex == 0xFF) {
|
|
// This is the max vertex, which we already did, but we
|
|
// have to account for it in the dither order
|
|
pulDitherOrder += pvVertexData->ulCount;
|
|
} else {
|
|
jColor = (BYTE) pvVertexData->ulVertex;
|
|
ulNumPixels = pvVertexData->ulCount;
|
|
switch (ulNumPixels & 3) {
|
|
case 3:
|
|
ajDither[*(pulDitherOrder+2)] = jColor;
|
|
case 2:
|
|
ajDither[*(pulDitherOrder+1)] = jColor;
|
|
case 1:
|
|
ajDither[*(pulDitherOrder+0)] = jColor;
|
|
pulDitherOrder += ulNumPixels & 3;
|
|
case 0:
|
|
break;
|
|
}
|
|
if ((ulNumPixels >>= 2) != 0) {
|
|
do {
|
|
ajDither[*pulDitherOrder] = jColor;
|
|
ajDither[*(pulDitherOrder+1)] = jColor;
|
|
ajDither[*(pulDitherOrder+2)] = jColor;
|
|
ajDither[*(pulDitherOrder+3)] = jColor;
|
|
pulDitherOrder += 4;
|
|
} while (--ulNumPixels);
|
|
}
|
|
}
|
|
} while (++pvVertexData < pvVertexDataEnd);
|
|
|
|
} else if (ulNumVertices == 2) {
|
|
|
|
// There are exactly two vertices with more than zero pixels; fill
|
|
// in the dither array as follows: block fill with vertex with more
|
|
// points first, then dither in the other vertex
|
|
if (vVertexData[0].ulCount >= vVertexData[1].ulCount) {
|
|
// There are no more vertex 1 than vertex 0 pixels, so do
|
|
// the block fill with vertex 0
|
|
ulColor = ulNibbleTo4bppDword[vVertexData[0].ulVertex];
|
|
// Do the dither with vertex 1
|
|
jColor = (BYTE) vVertexData[1].ulVertex;
|
|
ulNumPixels = vVertexData[1].ulCount;
|
|
// Set where to start dithering with vertex 1 (vertex 0 is
|
|
// lower intensity, so its pixels come first in the dither
|
|
// order)
|
|
pulDitherOrder = aulDither4bppOrder + vVertexData[0].ulCount;
|
|
} else {
|
|
// There are more vertex 1 pixels, so do the block fill
|
|
// with vertex 1
|
|
ulColor = ulNibbleTo4bppDword[vVertexData[1].ulVertex];
|
|
// Do the dither with vertex 0
|
|
jColor = (BYTE) vVertexData[0].ulVertex;
|
|
ulNumPixels = vVertexData[0].ulCount;
|
|
// Set where to start dithering with vertex 0 (vertex 0 is
|
|
// lower intensity, so its pixels come first in the dither
|
|
// order)
|
|
pulDitherOrder = aulDither4bppOrder;
|
|
}
|
|
|
|
// Block fill the dither pattern with the more common vertex
|
|
pulTemp = (ULONG *)ajDither;
|
|
*pulTemp = ulColor;
|
|
*(pulTemp+1) = ulColor;
|
|
*(pulTemp+2) = ulColor;
|
|
*(pulTemp+3) = ulColor;
|
|
*(pulTemp+4) = ulColor;
|
|
*(pulTemp+5) = ulColor;
|
|
*(pulTemp+6) = ulColor;
|
|
*(pulTemp+7) = ulColor;
|
|
*(pulTemp+8) = ulColor;
|
|
*(pulTemp+9) = ulColor;
|
|
*(pulTemp+10) = ulColor;
|
|
*(pulTemp+11) = ulColor;
|
|
*(pulTemp+12) = ulColor;
|
|
*(pulTemp+13) = ulColor;
|
|
*(pulTemp+14) = ulColor;
|
|
*(pulTemp+15) = ulColor;
|
|
|
|
// Dither in the less common vertex
|
|
switch (ulNumPixels & 3) {
|
|
case 3:
|
|
ajDither[*(pulDitherOrder+2)] = jColor;
|
|
case 2:
|
|
ajDither[*(pulDitherOrder+1)] = jColor;
|
|
case 1:
|
|
ajDither[*(pulDitherOrder+0)] = jColor;
|
|
pulDitherOrder += ulNumPixels & 3;
|
|
case 0:
|
|
break;
|
|
}
|
|
if ((ulNumPixels >>= 2) != 0) {
|
|
do {
|
|
ajDither[*pulDitherOrder] = jColor;
|
|
ajDither[*(pulDitherOrder+1)] = jColor;
|
|
ajDither[*(pulDitherOrder+2)] = jColor;
|
|
ajDither[*(pulDitherOrder+3)] = jColor;
|
|
pulDitherOrder += 4;
|
|
} while (--ulNumPixels);
|
|
}
|
|
|
|
} else {
|
|
|
|
// There is only one vertex in this dither
|
|
|
|
// No sorting or dithering is needed for just one color; we can
|
|
// just generate the final DIB directly
|
|
ulColor = ulNibbleTo4bppDword[vVertexData[0].ulVertex];
|
|
ulColor |= ulColor << 4;
|
|
*pulDest = ulColor;
|
|
*(pulDest+1) = ulColor;
|
|
*(pulDest+2) = ulColor;
|
|
*(pulDest+3) = ulColor;
|
|
*(pulDest+4) = ulColor;
|
|
*(pulDest+5) = ulColor;
|
|
*(pulDest+6) = ulColor;
|
|
*(pulDest+7) = ulColor;
|
|
|
|
return;
|
|
}
|
|
|
|
// Now convert the 64 bytes into the 4BPP Engine Format Bitmap
|
|
pulTemp = (ULONG *)ajDither;
|
|
|
|
*pulDest = (*pulTemp << 4) | *(pulTemp + 1);
|
|
*(pulDest + 1) = (*(pulTemp + 2) << 4) | *(pulTemp + 3);
|
|
*(pulDest + 2) = (*(pulTemp + 4) << 4) | *(pulTemp + 5);
|
|
*(pulDest + 3) = (*(pulTemp + 6) << 4) | *(pulTemp + 7);
|
|
*(pulDest + 4) = (*(pulTemp + 8) << 4) | *(pulTemp + 9);
|
|
*(pulDest + 5) = (*(pulTemp + 10) << 4) | *(pulTemp + 11);
|
|
*(pulDest + 6) = (*(pulTemp + 12) << 4) | *(pulTemp + 13);
|
|
*(pulDest + 7) = (*(pulTemp + 14) << 4) | *(pulTemp + 15);
|
|
}
|
|
|
|
|
|
/******************************Public*Routine******************************\
|
|
* EngDitherColor
|
|
*
|
|
* Dithers an RGB color to an 8X8 approximation using the reserved VGA
|
|
* colours.
|
|
*
|
|
\**************************************************************************/
|
|
|
|
ULONG EngDitherColor(
|
|
HDEV hdev,
|
|
ULONG iMode,
|
|
ULONG rgb,
|
|
ULONG* pul)
|
|
{
|
|
ULONG ulGrey, ulRed, ulGre, ulBlu, ulTemp, ulRet;
|
|
VERTEX_DATA vVertexData[4];
|
|
VERTEX_DATA *pvVertexData;
|
|
PDEVOBJ po(hdev);
|
|
|
|
ulRet = DCR_SOLID;
|
|
|
|
// We handle only 8x8 dithers. If the driver has their value set to
|
|
// something else, we have to bail.
|
|
|
|
if ((po.cxDither() != 8) || (po.cyDither() != 8))
|
|
{
|
|
WARNING("EngDitherColor works only when driver sets its DEVINFO");
|
|
WARNING("cxDither and cyDither values to 8");
|
|
}
|
|
else
|
|
{
|
|
// Figure out if we need a full color dither or only a monochrome dither.
|
|
|
|
// Note: we should get color dithers only at 8bpp and 4bpp, because
|
|
// those are the only color depths at which drivers should
|
|
// set GCAPS_COLOR_DITHER.
|
|
|
|
if (iMode != DM_MONOCHROME)
|
|
{
|
|
// We only handle 8bpp and 4bpp color dithers:
|
|
|
|
if (po.iDitherFormat() == BMF_8BPP ||
|
|
po.iDitherFormat() == BMF_4BPP)
|
|
{
|
|
// Full color dither
|
|
|
|
// Calculate what color subspaces are involved in the dither
|
|
pvVertexData = vComputeSubspaces(rgb, vVertexData);
|
|
|
|
// Now that we have found the bounding vertices and the number of
|
|
// pixels to dither for each vertex, we can create the dither pattern
|
|
|
|
// Handle 1, 2, and 3 & 4 vertices per dither separately
|
|
ulTemp = (ULONG) (pvVertexData - vVertexData);
|
|
// # of vertices with more than
|
|
// zero pixels in the dither
|
|
|
|
if (po.iDitherFormat() == BMF_8BPP)
|
|
{
|
|
vDitherColor8bpp(pul, vVertexData, pvVertexData, ulTemp);
|
|
}
|
|
else
|
|
{
|
|
vDitherColor4bpp(pul, vVertexData, pvVertexData, ulTemp);
|
|
}
|
|
|
|
ulRet = DCR_DRIVER;
|
|
}
|
|
else
|
|
{
|
|
WARNING("EngDitherColor works for DM_DEFAULT only when at 8bpp or 4bpp");
|
|
}
|
|
}
|
|
else
|
|
{
|
|
// Note: we can get monochrome dithers at any colour depth because
|
|
// we always set GCAPS_MONO_DITHER.
|
|
|
|
// For monochrome we will only use the Intensity (grey level)
|
|
|
|
RtlFillMemory((PVOID) pul, PATTERNSIZE/2, 0); // zero the dither bits
|
|
|
|
ulRed = (ULONG) ((PALETTEENTRY *) &rgb)->peRed;
|
|
ulGre = (ULONG) ((PALETTEENTRY *) &rgb)->peGreen;
|
|
ulBlu = (ULONG) ((PALETTEENTRY *) &rgb)->peBlue;
|
|
|
|
// I = .30R + .59G + .11B
|
|
// For convience the following ratios are used:
|
|
//
|
|
// 77/256 = 30.08%
|
|
// 151/256 = 58.98%
|
|
// 28/256 = 10.94%
|
|
|
|
ulGrey = (((ulRed * 77) + (ulGre * 151) + (ulBlu * 28)) >> 8) & 255;
|
|
|
|
// Convert the RGBI from 0-255 to 0-64 notation.
|
|
|
|
ulGrey = (ulGrey + 1) >> 2;
|
|
|
|
while(ulGrey) {
|
|
ulGrey--;
|
|
pul[ajByte[ulGrey]] |= ((ULONG) ajBits[ulGrey]);
|
|
}
|
|
|
|
ulRet = DCR_DRIVER;
|
|
}
|
|
}
|
|
|
|
return(ulRet);
|
|
}
|