Implementing Cover Scaling Mode

1SDL_Rect Image::MatchAspectRatio(
2  const SDL_Rect& Source,
3  const SDL_Rect& Target) const {
4  float TargetRatio{ Target.w
5    / static_cast<float>(Target.h) };
6  float SourceRatio{ Source.w
7    / static_cast<float>(Source.h) };
8
9  SDL_Rect ReturnValue = Source;
10
11  if (mScalingMode == ScalingMode::Contain) {
12    if (SourceRatio < TargetRatio) {
13      ReturnValue.h = static_cast<int>(
14        Source.w / TargetRatio);
15    } else {
16      ReturnValue.w = static_cast<int>(
17        Source.h * TargetRatio);
18    }
19  } else if (mScalingMode
20    == ScalingMode::Cover) {
21    if (SourceRatio > TargetRatio) {
22      int NewWidth = static_cast<int>(
23        Source.h * TargetRatio);
24      ReturnValue.w = NewWidth;
25    } else {
26      int NewHeight = static_cast<int>(
27        Source.w / TargetRatio);
28      ReturnValue.h = NewHeight;
29    }
30    ReturnValue.x =
31      (Target.w - ReturnValue.w) / 2;
32    ReturnValue.y =
33      (Target.h - ReturnValue.h) / 2;
34  }
35
36  return ReturnValue;
37}