0ct0pu5/wesnoth
1
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity Actions

Factored some computations.

Browse source
This commit is contained in:
Guillaume Melquiond 2010-12-20 22:38:32 +00:00
parent 8fab42db43
commit e250f1cd36
1 changed files with 13 additions and 13 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

26
src/sdl_utils.cpp
View file

@ -487,7 +487,7 @@ surface scale_surface(const surface &surf, int w, int h, bool optimize)
double xsrc = 0.0;
for(int xdst = 0; xdst != w; ++xdst, xsrc += xratio) {
double red = 0.0, green = 0.0, blue = 0.0, alpha = 0.0;
double summation = 0.0, a_summation = 0.0;
double summation = 0.0;
// We now have a rectangle, (xsrc,ysrc,xratio,yratio)
// which we want to derive the pixel from
@ -503,22 +503,22 @@ surface scale_surface(const surface &surf, int w, int h, bool optimize)
Uint8 r,g,b,a;
SDL_GetRGBA(src_pixels[yloc * src->w + xloc], src->format, &r, &g, &b, &a);
double value = xsize * ysize;
a_summation += value;
alpha += a * value;
value *= a / 255.0;
summation += value;
red += r*value;
green += g*value;
blue += b*value;
if (!a) continue;
value *= a;
alpha += value;
red += r * value;
green += g * value;
blue += b * value;
}
}
if (summation != 0.0) {
alpha /= a_summation;
summation = 1/summation;
red *= summation;
green *= summation;
blue *= summation;
if (alpha != 0.0) {
double factor = 1 / alpha;
alpha /= summation;
red *= factor;
green *= factor;
blue *= factor;
}
dst_pixels[ydst*dst->w + xdst] = SDL_MapRGBA(dst->format,Uint8(red),Uint8(green),Uint8(blue),Uint8(alpha));