1 | /* |
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2 | * libpipi Pathetic image processing interface 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 | * wave.c: wave and warping effects |
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17 | */ |
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18 | |
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19 | #include "config.h" |
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20 | |
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21 | #include <stdlib.h> |
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22 | #include <stdio.h> |
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23 | #include <string.h> |
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24 | #include <math.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 | pipi_image_t *pipi_wave(pipi_image_t *src, double freq, double phase, |
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30 | double theta, double xamp, double yamp) |
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31 | { |
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32 | pipi_image_t *dst; |
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33 | pipi_pixels_t *srcp, *dstp; |
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34 | float *srcdata, *dstdata; |
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35 | double sint, cost; |
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36 | int x, y, w, h, i, gray; |
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37 | |
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38 | w = src->w; |
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39 | h = src->h; |
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40 | |
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41 | gray = (src->last_modified == PIPI_PIXELS_Y_F32); |
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42 | |
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43 | srcp = gray ? pipi_get_pixels(src, PIPI_PIXELS_Y_F32) |
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44 | : pipi_get_pixels(src, PIPI_PIXELS_RGBA_F32); |
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45 | srcdata = (float *)srcp->pixels; |
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46 | |
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47 | dst = pipi_new(w, h); |
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48 | dstp = gray ? pipi_get_pixels(dst, PIPI_PIXELS_Y_F32) |
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49 | : pipi_get_pixels(dst, PIPI_PIXELS_RGBA_F32); |
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50 | dstdata = (float *)dstp->pixels; |
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51 | |
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52 | sint = sin(theta); |
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53 | cost = cos(theta); |
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54 | |
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55 | for(y = 0; y < h; y++) |
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56 | { |
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57 | for(x = 0; x < w; x++) |
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58 | { |
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59 | double t = cost * (x - w / 2) + sint * (y - h / 2); |
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60 | double step = sin(t * freq + phase); |
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61 | double dx = xamp; |
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62 | double dy = yamp; |
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63 | int x2, y2; |
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64 | |
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65 | if(x < 32) dx = dx * x / 32; |
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66 | if(x > w - 1 - 32) dx = dx * (w - 1 - x) / 32; |
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67 | if(y < 32) dy = dy * y / 32; |
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68 | if(y > h - 1 - 32) dy = dy * (h - 1 - y) / 32; |
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69 | |
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70 | x2 = x + dx * step; |
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71 | y2 = y + dy * step; |
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72 | |
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73 | /* Just in case... */ |
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74 | if(x2 < 0) x2 = 0; |
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75 | else if(x2 >= w) x2 = w - 1; |
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76 | |
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77 | if(y2 < 0) y2 = 0; |
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78 | else if(y2 >= h) y2 = h - 1; |
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79 | |
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80 | if(gray) |
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81 | { |
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82 | dstdata[y * w + x] = srcdata[y2 * w + x2]; |
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83 | } |
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84 | else |
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85 | { |
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86 | for(i = 0; i < 4; i++) |
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87 | { |
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88 | dstdata[4 * (y * w + x) + i] |
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89 | = srcdata[4 * (y2 * w + x2) + i]; |
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90 | } |
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91 | } |
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92 | } |
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93 | } |
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94 | |
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95 | return dst; |
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96 | } |
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97 | |
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