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wmaker/wrlib/rotate.c
Carlos R. Mafra 688a56e8ab Change to the linux kernel coding style
for arq in `git ls-files *.c`; do
    echo $arq;
    indent -linux -l115 $arq;
    done

The different line break at 115 columns is because
I use a widescreen monitor :-)
2009-08-20 00:59:40 +02:00

386 lines
7.1 KiB
C

/* rotate.c - image rotation
*
* Raster graphics library
*
* Copyright (c) 2000-2003 Alfredo K. Kojima
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Library General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Library General Public License for more details.
*
* You should have received a copy of the GNU Library General Public
* License along with this library; if not, write to the Free
* Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
#include <config.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <X11/Xlib.h>
#include "wraster.h"
#include <math.h>
#ifndef PI
#define PI 3.14159265358979323846
#endif
static RImage *rotateImage(RImage * image, float angle);
RImage *RRotateImage(RImage * image, float angle)
{
RImage *img;
int nwidth, nheight;
int x, y;
int bpp = image->format == RRGBAFormat ? 4 : 3;
angle = ((int)angle % 360) + (angle - (int)angle);
if (angle == 0.0) {
return RCloneImage(image);
} else if (angle == 90.0) {
nwidth = image->height;
nheight = image->width;
img = RCreateImage(nwidth, nheight, True);
if (!img) {
return NULL;
}
if (bpp == 3) {
unsigned char *optr, *nptr;
unsigned offs;
offs = nwidth * 4;
optr = image->data;
nptr = img->data;
for (x = 0; x < nwidth; x++) {
nptr = img->data + x * 4;
for (y = nheight; y; y--) {
nptr[0] = *optr++;
nptr[1] = *optr++;
nptr[2] = *optr++;
nptr[3] = 255;
nptr += offs;
}
}
} else {
unsigned *optr, *nptr;
unsigned *p;
optr = (unsigned *)image->data;
p = (unsigned *)img->data;
for (x = 0; x < nwidth; x++) {
nptr = p++;
for (y = nheight; y; y--) {
*nptr = *optr++;
nptr += nwidth;
}
}
}
} else if (angle == 180.0) {
nwidth = image->width;
nheight = image->height;
img = RCreateImage(nwidth, nheight, True);
if (!img) {
return NULL;
}
if (bpp == 3) {
unsigned char *optr, *nptr;
optr = image->data;
nptr = img->data + nwidth * nheight * 4 - 4;
for (y = 0; y < nheight; y++) {
for (x = 0; x < nwidth; x++) {
nptr[0] = optr[0];
nptr[1] = optr[1];
nptr[2] = optr[2];
nptr[3] = 255;
optr += 3;
nptr -= 4;
}
}
} else {
unsigned *optr, *nptr;
optr = (unsigned *)image->data;
nptr = (unsigned *)img->data + nwidth * nheight - 1;
for (y = nheight * nwidth - 1; y >= 0; y--) {
*nptr = *optr;
optr++;
nptr--;
}
}
} else if (angle == 270.0) {
nwidth = image->height;
nheight = image->width;
img = RCreateImage(nwidth, nheight, True);
if (!img) {
return NULL;
}
if (bpp == 3) {
unsigned char *optr, *nptr;
unsigned offs;
offs = nwidth * 4;
optr = image->data;
nptr = img->data;
for (x = 0; x < nwidth; x++) {
nptr = img->data + x * 4;
for (y = nheight; y; y--) {
nptr[0] = *optr++;
nptr[1] = *optr++;
nptr[2] = *optr++;
nptr[3] = 255;
nptr += offs;
}
}
} else {
unsigned *optr, *nptr;
unsigned *p;
optr = (unsigned *)image->data;
p = (unsigned *)img->data + nwidth * nheight;
for (x = 0; x < nwidth; x++) {
nptr = p--;
for (y = nheight; y; y--) {
*nptr = *optr++;
nptr -= nwidth;
}
}
}
} else {
img = rotateImage(image, angle);
}
return img;
}
/*
* Image rotation through Bresenham's line algorithm:
*
* If a square must be rotate by angle a, like in:
* _______
* | B |
* | /4\ |
* | /3 8\|
* | /2 7 /|
* |A1 6 / | A_______B
* | \5 / a| <--- |1 2 3 4|
* |__C/_)_| |5 6 7 8|
* C-------
*
* for each point P1 in the line from C to A
* for each point P2 in the perpendicular line starting at P1
* get pixel from the source and plot at P2
* increment pixel location from source
*
*/
static void
copyLine(int x1, int y1, int x2, int y2, int nwidth, int format, unsigned char *dst, unsigned char **src)
{
unsigned char *s = *src;
int dx, dy;
int xi, yi;
int offset;
int dpr, dpru, p;
dx = abs(x2 - x1);
dy = abs(y2 - y1);
if (x1 > x2)
xi = -1;
else
xi = 1;
if (y1 > y2)
yi = -1;
else
yi = 1;
if (dx >= dy) {
dpr = dy << 1;
dpru = dpr - (dx << 1);
p = dpr - dx;
while (dx-- >= 0) {
/* fetch and draw the pixel */
offset = (x1 + y1 * nwidth) << 2;
dst[offset++] = *s++;
dst[offset++] = *s++;
dst[offset++] = *s++;
if (format == RRGBAFormat)
dst[offset++] = *s++;
else
dst[offset++] = 255;
/* calc next step */
if (p > 0) {
x1 += xi;
y1 += yi;
p += dpru;
} else {
x1 += xi;
p += dpr;
}
}
} else {
dpr = dx << 1;
dpru = dpr - (dy << 1);
p = dpr - dy;
while (dy-- >= 0) {
/* fetch and draw the pixel */
offset = (x1 + y1 * nwidth) << 2;
dst[offset++] = *s++;
dst[offset++] = *s++;
dst[offset++] = *s++;
if (format == RRGBAFormat)
dst[offset++] = *s++;
else
dst[offset++] = 255;
/* calc next step */
if (p > 0) {
x1 += xi;
y1 += yi;
p += dpru;
} else {
y1 += yi;
p += dpr;
}
}
}
*src = s;
}
static RImage *rotateImage(RImage * image, float angle)
{
RImage *img;
int nwidth, nheight;
int x1, y1;
int x2, y2;
int dx, dy;
int xi, yi;
int xx, yy;
unsigned char *src, *dst;
int dpr, dpru, p;
/* only 180o for now */
if (angle > 180.0)
angle -= 180.0;
angle = (angle * PI) / 180.0;
nwidth = ceil(abs(cos(angle) * image->width))
+ ceil(abs(cos(PI / 2 - angle) * image->width));
nheight = ceil(abs(sin(angle) * image->height))
+ ceil(abs(cos(PI / 2 - angle) * image->height));
img = RCreateImage(nwidth, nheight, True);
if (!img)
return NULL;
src = image->data;
dst = img->data;
x1 = floor(abs(cos(PI / 2 - angle) * image->width));
y1 = 0;
x2 = 0;
y2 = floor(abs(sin(PI / 2 - angle) * image->width));
xx = floor(abs(cos(angle) * image->height)) - 1;
yy = nheight - 1;
printf("%ix%i, %i %i %i %i %i\n", nwidth, nheight, x1, y1, x2, y2, (int)((angle * 180.0) / PI));
dx = abs(x2 - x1);
dy = abs(y2 - y1);
if (x1 > x2)
xi = -1;
else
xi = 1;
if (y1 > y2)
yi = -1;
else
yi = 1;
if (dx >= dy) {
dpr = dy << 1;
dpru = dpr - (dx << 1);
p = dpr - dx;
while (dx-- >= 0) {
copyLine(x1, y1, xx, yy, nwidth, image->format, dst, &src);
/* calc next step */
if (p > 0) {
x1 += xi;
y1 += yi;
xx += xi;
yy += yi;
p += dpru;
} else {
x1 += xi;
xx += xi;
p += dpr;
}
}
} else {
puts("NOT IMPLEMTENED");
return img;
dpr = dx << 1;
dpru = dpr - (dy << 1);
p = dpr - dy;
while (dy-- >= 0) {
xx = abs(x1 * sin(angle * PI / 180.0));
yy = abs(y1 * cos(angle * PI / 180.0));
copyLine(x1, y1, xx, yy, nwidth, image->format, dst, &src);
/* calc next step */
if (p > 0) {
x1 += xi;
y1 += yi;
p += dpru;
} else {
y1 += yi;
p += dpr;
}
}
}
return img;
}