| 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 other 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 | #define BORDER 64 |
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| 30 | |
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| 31 | pipi_image_t *pipi_wave(pipi_image_t *src, double dw, double dh, |
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| 32 | double d, double a) |
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| 33 | { |
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| 34 | pipi_image_t *dst; |
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| 35 | pipi_pixels_t *srcp, *dstp; |
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| 36 | float *srcdata, *dstdata; |
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| 37 | double sina, cosa; |
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| 38 | int x, y, w, h, i, gray; |
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| 39 | |
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| 40 | w = src->w; |
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| 41 | h = src->h; |
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| 42 | |
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| 43 | gray = (src->last_modified == PIPI_PIXELS_Y_F32); |
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| 44 | |
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| 45 | srcp = gray ? pipi_get_pixels(src, PIPI_PIXELS_Y_F32) |
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| 46 | : pipi_get_pixels(src, PIPI_PIXELS_RGBA_F32); |
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| 47 | srcdata = (float *)srcp->pixels; |
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| 48 | |
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| 49 | dst = pipi_new(w, h); |
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| 50 | dstp = gray ? pipi_get_pixels(dst, PIPI_PIXELS_Y_F32) |
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| 51 | : pipi_get_pixels(dst, PIPI_PIXELS_RGBA_F32); |
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| 52 | dstdata = (float *)dstp->pixels; |
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| 53 | |
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| 54 | sina = sin(a); |
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| 55 | cosa = cos(a); |
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| 56 | |
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| 57 | for(y = 0; y < h; y++) |
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| 58 | { |
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| 59 | for(x = 0; x < w; x++) |
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| 60 | { |
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| 61 | double angle = 2 * M_PI / dw * ((x - w / 2) * cosa |
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| 62 | + (y - h / 2) * sina - d); |
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| 63 | double displacement = dh * sin(angle); |
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| 64 | double dx, dy; |
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| 65 | int x2, y2; |
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| 66 | |
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| 67 | dx = cosa * displacement; |
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| 68 | dy = sina * displacement; |
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| 69 | |
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| 70 | if(x < BORDER) dx = dx * x / BORDER; |
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| 71 | if(x > w - 1 - BORDER) dx = dx * (w - 1 - x) / BORDER; |
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| 72 | if(y < BORDER) dy = dy * y / BORDER; |
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| 73 | if(y > h - 1 - BORDER) dy = dy * (h - 1 - y) / BORDER; |
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| 74 | |
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| 75 | x2 = x + dx; |
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| 76 | y2 = y + dy; |
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| 77 | |
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| 78 | /* Just in case... */ |
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| 79 | if(x2 < 0) x2 = 0; |
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| 80 | else if(x2 >= w) x2 = w - 1; |
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| 81 | |
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| 82 | if(y2 < 0) y2 = 0; |
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| 83 | else if(y2 >= h) y2 = h - 1; |
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| 84 | |
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| 85 | if(gray) |
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| 86 | { |
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| 87 | dstdata[y * w + x] = srcdata[y2 * w + x2]; |
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| 88 | } |
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| 89 | else |
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| 90 | { |
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| 91 | for(i = 0; i < 4; i++) |
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| 92 | { |
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| 93 | dstdata[4 * (y * w + x) + i] |
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| 94 | = srcdata[4 * (y2 * w + x2) + i]; |
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| 95 | } |
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| 96 | } |
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| 97 | } |
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| 98 | } |
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| 99 | |
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| 100 | return dst; |
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| 101 | } |
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| 102 | |
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| 103 | pipi_image_t *pipi_sine(pipi_image_t *src, double dw, double dh, |
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| 104 | double d, double a) |
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| 105 | { |
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| 106 | pipi_image_t *dst; |
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| 107 | pipi_pixels_t *srcp, *dstp; |
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| 108 | float *srcdata, *dstdata; |
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| 109 | double sina, cosa; |
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| 110 | int x, y, w, h, i, gray; |
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| 111 | |
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| 112 | w = src->w; |
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| 113 | h = src->h; |
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| 114 | |
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| 115 | gray = (src->last_modified == PIPI_PIXELS_Y_F32); |
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| 116 | |
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| 117 | srcp = gray ? pipi_get_pixels(src, PIPI_PIXELS_Y_F32) |
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| 118 | : pipi_get_pixels(src, PIPI_PIXELS_RGBA_F32); |
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| 119 | srcdata = (float *)srcp->pixels; |
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| 120 | |
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| 121 | dst = pipi_new(w, h); |
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| 122 | dstp = gray ? pipi_get_pixels(dst, PIPI_PIXELS_Y_F32) |
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| 123 | : pipi_get_pixels(dst, PIPI_PIXELS_RGBA_F32); |
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| 124 | dstdata = (float *)dstp->pixels; |
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| 125 | |
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| 126 | sina = sin(a); |
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| 127 | cosa = cos(a); |
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| 128 | |
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| 129 | for(y = 0; y < h; y++) |
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| 130 | { |
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| 131 | for(x = 0; x < w; x++) |
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| 132 | { |
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| 133 | double angle = 2 * M_PI / dw * ((x - w / 2) * cosa |
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| 134 | + (y - h / 2) * sina - d); |
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| 135 | double displacement = dh * sin(angle); |
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| 136 | double dx, dy; |
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| 137 | int x2, y2; |
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| 138 | |
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| 139 | dx = -sina * displacement; |
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| 140 | dy = cosa * displacement; |
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| 141 | |
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| 142 | if(x < BORDER) dx = dx * x / BORDER; |
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| 143 | if(x > w - 1 - BORDER) dx = dx * (w - 1 - x) / BORDER; |
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| 144 | if(y < BORDER) dy = dy * y / BORDER; |
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| 145 | if(y > h - 1 - BORDER) dy = dy * (h - 1 - y) / BORDER; |
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| 146 | |
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| 147 | x2 = x + dx; |
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| 148 | y2 = y + dy; |
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| 149 | |
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| 150 | /* Just in case... */ |
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| 151 | if(x2 < 0) x2 = 0; |
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| 152 | else if(x2 >= w) x2 = w - 1; |
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| 153 | |
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| 154 | if(y2 < 0) y2 = 0; |
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| 155 | else if(y2 >= h) y2 = h - 1; |
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| 156 | |
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| 157 | if(gray) |
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| 158 | { |
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| 159 | dstdata[y * w + x] = srcdata[y2 * w + x2]; |
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| 160 | } |
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| 161 | else |
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| 162 | { |
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| 163 | for(i = 0; i < 4; i++) |
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| 164 | { |
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| 165 | dstdata[4 * (y * w + x) + i] |
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| 166 | = srcdata[4 * (y2 * w + x2) + i]; |
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| 167 | } |
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| 168 | } |
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| 169 | } |
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| 170 | } |
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| 171 | |
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| 172 | return dst; |
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| 173 | } |
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| 174 | |
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