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- don't double convert to radian

master
pajoye 2008-02-28 09:49:52 +00:00
parent 51f2fe8934
commit e253210769
1 changed files with 13 additions and 5 deletions
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18
examples/copyrotated.c
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@ -38,7 +38,7 @@ int main(int argc, char **arg)
{
gdImagePtr im, im2;
int new_width, new_height;
double angle;
double angle, a2;
if (argc < 3) {
fprintf(stderr, "Usage: copyrotated [angle in degree] [filename.png]\n");
@ -55,12 +55,16 @@ int main(int argc, char **arg)
/*
cos adj hyp (cos = adjacent / hypothenus)
sin op hyp (sin adjacent / hypothenus)
+ 10 pixels margin
*/
new_width = cos(angle * .0174532925) * gdImageSX(im)
- sin(angle * .0174532925) * gdImageSY(im) + 1;
new_height = - sin(angle * .0174532925) * gdImageSX(im)
+ cos(angle * .0174532925) * gdImageSY(im) + 1;
/* to radian */
a2 = angle * .0174532925;
new_width = ceil(cos(a2) * gdImageSX(im)) +
fabs(sin(a2) * gdImageSY(im));
new_height = ceil(cos(a2) * gdImageSY(im)) +
fabs(sin(a2) * gdImageSX(im));
im2 = gdImageCreateTrueColor(new_width, new_height);
@ -70,7 +74,11 @@ int main(int argc, char **arg)
return 1;
}
gdImageAlphaBlending(im2, 0);
gdImageFilledRectangle(im2, 0, 0, gdImageSX(im2), gdImageSY(im2), gdTrueColorAlpha(127,0,0,127));
gdImageCopyRotated(im2, im, new_width/2, new_height/2, 0, 0, gdImageSX(im), gdImageSY(im), angle);
gdImageSaveAlpha(im2, 1);
if (!savePngImage(im2, "rotated.png")) {
fprintf(stderr, "Can't save PNG file rotated.png");
gdImageDestroy(im);