| 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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