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game/math/mathutils.c

@@ -0,0 +1,49 @@
+#include "mathutils.h"
+#include "../../gfx/gfx.h"
+#include <corecrt_math.h>
+
+point scale_to_screen(
+		double x,
+		double y,
+		double w_meters,
+		double h_meters,
+		double x_off,
+		double y_off)
+{
+	return (point) {
+		.x = x * ((double) SCREEN_WIDTH  / w_meters) + x_off,
+		.y = y * ((double) SCREEN_HEIGHT / h_meters) + y_off,
+	};
+}
+
+point scale_to_field(
+		double x,
+		double y,
+		double w_meters,
+		double h_meters,
+		double x_off,
+		double y_off)
+{
+	return (point) {
+		.x = (x - x_off) / ((double) SCREEN_WIDTH  / w_meters),
+		.y = (y - y_off) / ((double) SCREEN_HEIGHT / h_meters),
+	};
+}
+
+bool within_box(point p, rect r) {
+	return p.x >= r.x && p.y >= r.y &&
+		p.x <= r.x + r.w && p.y <= r.y + r.h;
+}
+
+point lerp_point(point a, point b, float p) {
+	return (point) {
+			a.x + (b.x - a.x) * p,
+			a.y + (b.y - a.y) * p
+	};
+}
+
+double get_distance(point a, point b) {
+	return sqrt(
+			(a.x - b.x) * (a.x - b.x) +
+			(a.y - b.y) * (a.y - b.y));
+}