| /* |
| * Dithering functions |
| * |
| * Copyright 1994 Alexandre Julliard |
| */ |
| |
| static char Copyright[] = "Copyright Alexandre Julliard, 1994"; |
| |
| #include <stdlib.h> |
| #include <X11/Xlib.h> |
| #include <X11/Xutil.h> |
| |
| #include "gdi.h" |
| #include "bitmap.h" |
| |
| |
| /* Levels of each primary */ |
| #define PRIMARY_LEVELS 3 |
| #define TOTAL_LEVELS (PRIMARY_LEVELS*PRIMARY_LEVELS*PRIMARY_LEVELS) |
| |
| /* Dithering matrix size */ |
| #define MATRIX_SIZE 8 |
| #define MATRIX_SIZE_2 (MATRIX_SIZE*MATRIX_SIZE) |
| |
| /* Total number of possible levels for a dithered primary color */ |
| #define DITHER_LEVELS (MATRIX_SIZE_2 * (PRIMARY_LEVELS-1) + 1) |
| |
| /* Dithering matrix */ |
| static const int dither_matrix[MATRIX_SIZE_2] = |
| { |
| 0, 32, 8, 40, 2, 34, 10, 42, |
| 48, 16, 56, 24, 50, 18, 58, 26, |
| 12, 44, 4, 36, 14, 46, 6, 38, |
| 60, 28, 52, 20, 62, 30, 54, 22, |
| 3, 35, 11, 43, 1, 33, 9, 41, |
| 51, 19, 59, 27, 49, 17, 57, 25, |
| 15, 47, 7, 39, 13, 45, 5, 37, |
| 63, 31, 55, 23, 61, 29, 53, 21 |
| }; |
| |
| /* Mapping between (R,G,B) triples and EGA colors */ |
| static const int EGAmapping[TOTAL_LEVELS] = |
| { |
| 0, /* 000000 -> 000000 */ |
| 4, /* 00007f -> 000080 */ |
| 12, /* 0000ff -> 0000ff */ |
| 2, /* 007f00 -> 008000 */ |
| 6, /* 007f7f -> 008080 */ |
| 6, /* 007fff -> 008080 */ |
| 10, /* 00ff00 -> 00ff00 */ |
| 6, /* 00ff7f -> 008080 */ |
| 14, /* 00ffff -> 00ffff */ |
| 1, /* 7f0000 -> 800000 */ |
| 5, /* 7f007f -> 800080 */ |
| 5, /* 7f00ff -> 800080 */ |
| 3, /* 7f7f00 -> 808000 */ |
| 8, /* 7f7f7f -> 808080 */ |
| 7, /* 7f7fff -> c0c0c0 */ |
| 3, /* 7fff00 -> 808000 */ |
| 7, /* 7fff7f -> c0c0c0 */ |
| 7, /* 7fffff -> c0c0c0 */ |
| 9, /* ff0000 -> ff0000 */ |
| 5, /* ff007f -> 800080 */ |
| 13, /* ff00ff -> ff00ff */ |
| 3, /* ff7f00 -> 808000 */ |
| 7, /* ff7f7f -> c0c0c0 */ |
| 7, /* ff7fff -> c0c0c0 */ |
| 11, /* ffff00 -> ffff00 */ |
| 7, /* ffff7f -> c0c0c0 */ |
| 15 /* ffffff -> ffffff */ |
| }; |
| |
| /* Map an EGA index (0..15) to a pixel value */ |
| extern int COLOR_mapEGAPixel[16]; /* in color.c */ |
| |
| #define PIXEL_VALUE(r,g,b) \ |
| COLOR_mapEGAPixel[EGAmapping[((r)*PRIMARY_LEVELS+(g))*PRIMARY_LEVELS+(b)]] |
| |
| /* X image for building dithered pixmap */ |
| static XImage *ditherImage = NULL; |
| static char *imageData = NULL; |
| |
| |
| /*********************************************************************** |
| * DITHER_Init |
| * |
| * Create the X image used for dithering. |
| */ |
| BOOL DITHER_Init() |
| { |
| int bytes_per_line = (screenDepth * MATRIX_SIZE + 7) / 8; |
| if (!(imageData = (char *) malloc( bytes_per_line * MATRIX_SIZE ))) |
| return FALSE; |
| ditherImage = XCreateImage( display, DefaultVisualOfScreen(screen), |
| screenDepth, ZPixmap, 0, imageData, |
| MATRIX_SIZE, MATRIX_SIZE, 8, bytes_per_line ); |
| return (ditherImage != NULL); |
| } |
| |
| |
| /*********************************************************************** |
| * DITHER_DitherColor |
| */ |
| Pixmap DITHER_DitherColor( DC *dc, COLORREF color ) |
| { |
| static COLORREF prevColor = 0xffffffff; |
| unsigned int x, y; |
| Pixmap pixmap; |
| |
| /* printf( "Dither: %x\n", color ); */ |
| |
| if (color != prevColor) |
| { |
| int r = GetRValue( color ) * DITHER_LEVELS; |
| int g = GetGValue( color ) * DITHER_LEVELS; |
| int b = GetBValue( color ) * DITHER_LEVELS; |
| const int *pmatrix = dither_matrix; |
| |
| WORD *mapping = (WORD *) GDI_HEAP_ADDR( dc->u.x.pal.hMapping ); |
| |
| for (y = 0; y < MATRIX_SIZE; y++) |
| { |
| for (x = 0; x < MATRIX_SIZE; x++) |
| { |
| int d = *pmatrix++ * 256; |
| int dr = ((r + d) / MATRIX_SIZE_2) / 256; |
| int dg = ((g + d) / MATRIX_SIZE_2) / 256; |
| int db = ((b + d) / MATRIX_SIZE_2) / 256; |
| XPutPixel( ditherImage, x, y, PIXEL_VALUE(dr,dg,db) ); |
| } |
| } |
| prevColor = color; |
| } |
| |
| pixmap = XCreatePixmap( display, rootWindow, |
| MATRIX_SIZE, MATRIX_SIZE, screenDepth ); |
| XPutImage( display, pixmap, BITMAP_colorGC, ditherImage, 0, 0, |
| 0, 0, MATRIX_SIZE, MATRIX_SIZE ); |
| return pixmap; |
| } |