X-Git-Url: http://git.tdb.fi/?p=libs%2Fgl.git;a=blobdiff_plain;f=source%2Fcore%2Frect.h;h=e118b39b8c82d7da4d7b35cb00544a7ad487b71c;hp=333dbc25f7aa0466bd706acc13f279cb15b9c89e;hb=HEAD;hpb=ce3658993ce2f6b7527a04a36a5e1af349c6f2e9

diff --git a/source/core/rect.h b/source/core/rect.h
index 333dbc25..e118b39b 100644
--- a/source/core/rect.h
+++ b/source/core/rect.h
@@ -1,20 +1,57 @@
 #ifndef MSP_GL_RECT_H_
 #define MSP_GL_RECT_H_
 
+#include <algorithm>
+#include <limits>
+
 namespace Msp {
 namespace GL {
 
 struct Rect
 {
-	int left;
-	int bottom;
-	unsigned width;
-	unsigned height;
+	int left = 0;
+	int bottom = 0;
+	unsigned width = 0;
+	unsigned height = 0;
 
-	Rect(): left(0), bottom(0), width(0), height(0) { }
+	Rect() = default;
 	Rect(int l, int b, unsigned w, unsigned h): left(l), bottom(b), width(w), height(h) { }
+
+	static Rect max() { unsigned s = std::numeric_limits<unsigned>::max(); return Rect(0, 0, s, s); }
+
+	bool operator==(const Rect &) const;
+	bool operator!=(const Rect &r) const { return !operator==(r); }
+
+	Rect intersect(const Rect &) const;
 };
 
+inline bool Rect::operator==(const Rect &other) const
+{
+	return left==other.left && bottom==other.bottom && width==other.width && height==other.height;
+}
+
+inline Rect Rect::intersect(const Rect &other) const
+{
+	auto intersect_axis = [](int &s1, unsigned &z1, int s2, unsigned z2){
+		if(s2>s1)
+		{
+			unsigned d = s2-s1;
+			z1 = (d>z1 ? 0 : std::min(z1-d, z2));
+			s1 = s2;
+		}
+		else
+		{
+			unsigned d = s1-s2;
+			z1 = (d>z2 ? 0 : std::min(z2-d, z1));
+		}
+	};
+
+	Rect result = *this;
+	intersect_axis(result.left, result.width, other.left, other.width);
+	intersect_axis(result.bottom, result.height, other.bottom, other.height);
+	return result;
+}
+
 } // namespace GL
 } // namespace Msp