static int
UpdateLogicalSize(SDL_Renderer *renderer)
{
int w, h;
float want_aspect;
float real_aspect;
float scale;
SDL_Rect viewport;
if (SDL_GetRendererOutputSize(renderer, &w, &h) < 0) {
return -1;
}
want_aspect = (float)renderer->logical_w / renderer->logical_h;
real_aspect = (float)w / h;
/* Clear the scale because we're setting viewport in output coordinates */
SDL_RenderSetScale(renderer, 1.0f, 1.0f);
if (SDL_fabs(want_aspect-real_aspect) < 0.0001) {
/* The aspect ratios are the same, just scale appropriately */
scale = (float)w / renderer->logical_w;
SDL_RenderSetViewport(renderer, NULL);
} else if (want_aspect > real_aspect) {
/* We want a wider aspect ratio than is available - letterbox it */
scale = (float)w / renderer->logical_w;
viewport.x = 0;
viewport.w = w;
viewport.h = (int)SDL_ceil(renderer->logical_h * scale);
viewport.y = (h - viewport.h) / 2;
SDL_RenderSetViewport(renderer, &viewport);
} else {
/* We want a narrower aspect ratio than is available - use side-bars */
scale = (float)h / renderer->logical_h;
viewport.y = 0;
viewport.h = h;
viewport.w = (int)SDL_ceil(renderer->logical_w * scale);
viewport.x = (w - viewport.w) / 2;
SDL_RenderSetViewport(renderer, &viewport);
}
/* Set the new scale */
SDL_RenderSetScale(renderer, scale, scale);
return 0;
}
static float bestDollarDifference(SDL_FloatPoint* points,SDL_FloatPoint* templ)
{
/*------------BEGIN DOLLAR BLACKBOX------------------
-TRANSLATED DIRECTLY FROM PSUDEO-CODE AVAILABLE AT-
-"http://depts.washington.edu/aimgroup/proj/dollar/"
*/
double ta = -M_PI/4;
double tb = M_PI/4;
double dt = M_PI/90;
float x1 = (float)(PHI*ta + (1-PHI)*tb);
float f1 = dollarDifference(points,templ,x1);
float x2 = (float)((1-PHI)*ta + PHI*tb);
float f2 = dollarDifference(points,templ,x2);
while (SDL_fabs(ta-tb) > dt) {
if (f1 < f2) {
tb = x2;
x2 = x1;
f2 = f1;
x1 = (float)(PHI*ta + (1-PHI)*tb);
f1 = dollarDifference(points,templ,x1);
}
else {
ta = x1;
x1 = x2;
f1 = f2;
x2 = (float)((1-PHI)*ta + PHI*tb);
f2 = dollarDifference(points,templ,x2);
}
}
/*
if (f1 <= f2)
printf("Min angle (x1): %f\n",x1);
else if (f1 > f2)
printf("Min angle (x2): %f\n",x2);
*/
return SDL_min(f1,f2);
}
