58 lines
1.8 KiB
C
58 lines
1.8 KiB
C
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#include "Types.h"
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static inline double dmin(double x, double y) {
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return x < y ? x : y;
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}
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static inline double dmax(double x, double y) {
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return x > y ? x : y;
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}
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Vec2 vec2_Add(Vec2 x, Vec2 y) {
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Vec2 result = {
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.x = x.x + y.x,
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.y = x.y + y.y};
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return result;
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}
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Vec2 vec2_Scale(Vec2 v, double scale) {
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Vec2 result = {
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.x = v.x * scale,
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.y = v.y * scale};
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return result;
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}
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bool box2_Intersects(const Box2 x, const Box2 y, Box2 *out_intersection) {
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// Compute the min and max of the first rectangle on both axes
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const double r1MinX = dmin(x.lefttop.x, x.lefttop.x + x.size.x);
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const double r1MaxX = dmax(x.lefttop.x, x.lefttop.x + x.size.x);
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const double r1MinY = dmin(x.lefttop.y, x.lefttop.x + x.size.x);
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const double r1MaxY = dmax(x.lefttop.y, x.lefttop.x + x.size.x);
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// Compute the min and max of the second rectangle on both axes
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const double r2MinX = dmin(y.lefttop.x, y.lefttop.x + y.size.x);
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const double r2MaxX = dmax(y.lefttop.x, y.lefttop.x + y.size.x);
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const double r2MinY = dmin(y.lefttop.y, y.lefttop.y + y.size.y);
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const double r2MaxY = dmax(y.lefttop.y, y.lefttop.y + y.size.y);
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// Compute the intersection boundaries
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const double interLeft = dmax(r1MinX, r2MinX);
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const double interTop = dmax(r1MinY, r2MinY);
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const double interRight = dmin(r1MaxX, r2MaxX);
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const double interBottom = dmin(r1MaxY, r2MaxY);
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// If the intersection is valid (positive non zero area), then there is an intersection
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if ((interLeft < interRight) && (interTop < interBottom)) {
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if (out_intersection) {
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out_intersection->lefttop.x = interLeft;
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out_intersection->lefttop.y = interTop;
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out_intersection->size.x = interRight - interLeft;
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out_intersection->size.y = interBottom - interTop;
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}
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return true;
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} else {
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return false;
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}
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}
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