| 1 | /* |
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| 2 | * libpipi Proper image processing implementation library |
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| 3 | * Copyright (c) 2004-2008 Sam Hocevar <sam@zoy.org> |
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| 4 | * All Rights Reserved |
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| 5 | * |
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| 6 | * $Id$ |
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| 7 | * |
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| 8 | * This library is free software. It comes without any warranty, to |
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| 9 | * the extent permitted by applicable law. You can redistribute it |
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| 10 | * and/or modify it under the terms of the Do What The Fuck You Want |
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| 11 | * To Public License, Version 2, as published by Sam Hocevar. See |
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| 12 | * http://sam.zoy.org/wtfpl/COPYING for more details. |
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| 13 | */ |
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| 14 | |
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| 15 | /* |
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| 16 | * dither.c: dithering functions |
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| 17 | */ |
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| 18 | |
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| 19 | #include "config.h" |
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| 20 | #include "common.h" |
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| 21 | |
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| 22 | #include <stdio.h> |
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| 23 | #include <stdlib.h> |
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| 24 | #include <string.h> |
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| 25 | |
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| 26 | #include "pipi.h" |
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| 27 | #include "pipi_internals.h" |
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| 28 | |
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| 29 | void pipi_dither_24to16(pipi_image_t *img) |
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| 30 | { |
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| 31 | /* XXX: disabled because this is not the right place... see pixels.c instead */ |
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| 32 | #if 0 |
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| 33 | int *error, *nexterror; |
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| 34 | uint32_t *p32; |
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| 35 | int x, y; |
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| 36 | |
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| 37 | error = malloc(sizeof(int) * 3 * (img->width + 2)); |
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| 38 | nexterror = malloc(sizeof(int) * 3 * (img->width + 2)); |
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| 39 | p32 = (uint32_t *)img->pixels; |
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| 40 | |
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| 41 | memset(error, 0, sizeof(int) * 3 * (img->width + 2)); |
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| 42 | |
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| 43 | for(y = 0; y < img->height; y++) |
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| 44 | { |
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| 45 | int er = 0, eg = 0, eb = 0; |
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| 46 | |
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| 47 | memset(nexterror, 0, sizeof(int) * 3 * (img->width + 2)); |
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| 48 | |
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| 49 | for(x = 0; x < img->width; x++) |
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| 50 | { |
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| 51 | int r, g, b, r2, g2, b2; |
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| 52 | r = p32[y * img->width + x] & 0xff; |
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| 53 | g = (p32[y * img->width + x] >> 8) & 0xff; |
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| 54 | b = (p32[y * img->width + x] >> 16) & 0xff; |
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| 55 | r += er + error[x * 3 + 3]; |
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| 56 | g += eg + error[x * 3 + 4]; |
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| 57 | b += eb + error[x * 3 + 5]; |
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| 58 | r2 = r / 8 * 8; g2 = g / 4 * 4; b2 = b / 8 * 8; |
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| 59 | if(r2 < 0) r2 = 0; if(r2 > 0xf8) r2 = 0xf8; |
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| 60 | if(g2 < 0) g2 = 0; if(g2 > 0xfc) g2 = 0xfc; |
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| 61 | if(b2 < 0) b2 = 0; if(b2 > 0xf8) b2 = 0xf8; |
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| 62 | /* hack */ |
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| 63 | if(r2 == 0x88 && g2 == 0x88 && b2 == 0x88) g2 = 0x84; |
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| 64 | /* hack */ |
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| 65 | p32[y * img->width + x] = (b2 << 16) | (g2 << 8) | r2; |
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| 66 | |
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| 67 | er = r - (r2 / 8 * 255 / 31); |
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| 68 | eg = g - (g2 / 4 * 255 / 63); |
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| 69 | eb = b - (b2 / 8 * 255 / 31); |
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| 70 | nexterror[x * 3 + 0] += er * 3 / 8; |
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| 71 | nexterror[x * 3 + 1] += eg * 3 / 8; |
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| 72 | nexterror[x * 3 + 2] += eb * 3 / 8; |
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| 73 | nexterror[x * 3 + 3] += er * 5 / 8; |
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| 74 | nexterror[x * 3 + 4] += eg * 5 / 8; |
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| 75 | nexterror[x * 3 + 5] += eb * 5 / 8; |
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| 76 | nexterror[x * 3 + 6] += er * 1 / 8; |
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| 77 | nexterror[x * 3 + 7] += eg * 1 / 8; |
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| 78 | nexterror[x * 3 + 8] += eb * 1 / 8; |
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| 79 | er -= er * 3 / 8 + er * 7 / 8 + er * 1 / 8; |
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| 80 | eg -= eg * 3 / 8 + eg * 7 / 8 + eg * 1 / 8; |
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| 81 | eb -= eb * 3 / 8 + eb * 7 / 8 + eb * 1 / 8; |
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| 82 | } |
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| 83 | |
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| 84 | memcpy(error, nexterror, sizeof(int) * 3 * (img->width + 2)); |
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| 85 | } |
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| 86 | |
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| 87 | free(error); |
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| 88 | free(nexterror); |
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| 89 | #endif |
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| 90 | } |
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| 91 | |
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