Begin move to SDL

src/basic/math.cpp

@@ -0,0 +1,145 @@
+struct Vec2 {
+    float x;
+    float y;
+};
+
+struct Rect2 {
+    Vec2 min;
+    Vec2 max;
+};
+
+Vec2 GetSize(Rect2 r) {
+    Vec2 result = {r.max.x - r.min.x, r.max.y - r.min.y};
+    return result;
+}
+
+Vec2 GetSizeF(Rect2I r) {
+    Vec2 result = {(float)(r.max.x - r.min.x), (float)(r.max.y - r.min.y)};
+    return result;
+}
+
+Vec2   ToVec2(Vec2I v) { return {(float)v.x, (float)v.y}; }
+Vec2I  ToVec2I(Vec2 v) { return {(Int)v.x, (Int)v.y}; }
+Rect2I ToRect2I(Rect2 r) { return {ToVec2I(r.min), ToVec2I(r.max)}; }
+
+// clang-format off
+Rect2 operator-(Rect2 r, Rect2 value) { return { r.min.x - value.min.x, r.min.y - value.min.y, r.max.x - value.max.x, r.max.y - value.max.y }; }
+Rect2 operator+(Rect2 r, Rect2 value) { return { r.min.x + value.min.x, r.min.y + value.min.y, r.max.x + value.max.x, r.max.y + value.max.y }; }
+Rect2 operator*(Rect2 r, Rect2 value) { return { r.min.x * value.min.x, r.min.y * value.min.y, r.max.x * value.max.x, r.max.y * value.max.y }; }
+Rect2 operator/(Rect2 r, Rect2 value) { return { r.min.x / value.min.x, r.min.y / value.min.y, r.max.x / value.max.x, r.max.y / value.max.y }; }
+
+Rect2 operator-(Rect2 r, Vec2 value) { return { r.min.x - value.x, r.min.y - value.y, r.max.x - value.x, r.max.y - value.y }; }
+Rect2 operator+(Rect2 r, Vec2 value) { return { r.min.x + value.x, r.min.y + value.y, r.max.x + value.x, r.max.y + value.y }; }
+Rect2 operator*(Rect2 r, Vec2 value) { return { r.min.x * value.x, r.min.y * value.y, r.max.x * value.x, r.max.y * value.y }; }
+Rect2 operator/(Rect2 r, Vec2 value) { return { r.min.x / value.x, r.min.y / value.y, r.max.x / value.x, r.max.y / value.y }; }
+
+Rect2 operator-(Rect2 r, float value) { return { r.min.x - value, r.min.y - value, r.max.x - value, r.max.y - value }; }
+Rect2 operator+(Rect2 r, float value) { return { r.min.x + value, r.min.y + value, r.max.x + value, r.max.y + value }; }
+Rect2 operator*(Rect2 r, float value) { return { r.min.x * value, r.min.y * value, r.max.x * value, r.max.y * value }; }
+Rect2 operator/(Rect2 r, float value) { return { r.min.x / value, r.min.y / value, r.max.x / value, r.max.y / value }; }
+
+Rect2 operator-=(Rect2 &r, Rect2 value) { r = r - value; return r; }
+Rect2 operator+=(Rect2 &r, Rect2 value) { r = r + value; return r; }
+Rect2 operator*=(Rect2 &r, Rect2 value) { r = r * value; return r; }
+Rect2 operator/=(Rect2 &r, Rect2 value) { r = r / value; return r; }
+Rect2 operator-=(Rect2 &r, Vec2 value) { r = r - value; return r; }
+Rect2 operator+=(Rect2 &r, Vec2 value) { r = r + value; return r; }
+Rect2 operator*=(Rect2 &r, Vec2 value) { r = r * value; return r; }
+Rect2 operator/=(Rect2 &r, Vec2 value) { r = r / value; return r; }
+Rect2 operator-=(Rect2 &r, float value) { r = r - value; return r; }
+Rect2 operator+=(Rect2 &r, float value) { r = r + value; return r; }
+Rect2 operator*=(Rect2 &r, float value) { r = r * value; return r; }
+Rect2 operator/=(Rect2 &r, float value) { r = r / value; return r; }
+
+Vec2 operator-(Vec2 a, Vec2 b) { return {a.x - b.x, a.y - b.y}; }
+Vec2 operator+(Vec2 a, Vec2 b) { return {a.x + b.x, a.y + b.y}; }
+Vec2 operator*(Vec2 a, Vec2 b) { return {a.x * b.x, a.y * b.y}; }
+Vec2 operator/(Vec2 a, Vec2 b) { return {a.x / b.x, a.y / b.y}; }
+
+Vec2 operator-(Vec2 a, float b) { return {a.x - b, a.y - b}; }
+Vec2 operator+(Vec2 a, float b) { return {a.x + b, a.y + b}; }
+Vec2 operator*(Vec2 a, float b) { return {a.x * b, a.y * b}; }
+Vec2 operator/(Vec2 a, float b) { return {a.x / b, a.y / b}; }
+
+Vec2 operator-=(Vec2 &a, Vec2 b) { a = a - b; return a; }
+Vec2 operator+=(Vec2 &a, Vec2 b) { a = a + b; return a; }
+Vec2 operator*=(Vec2 &a, Vec2 b) { a = a * b; return a; }
+Vec2 operator/=(Vec2 &a, Vec2 b) { a = a / b; return a; }
+Vec2 operator-=(Vec2 &a, float b) { a = a - b; return a; }
+Vec2 operator+=(Vec2 &a, float b) { a = a + b; return a; }
+Vec2 operator*=(Vec2 &a, float b) { a = a * b; return a; }
+Vec2 operator/=(Vec2 &a, float b) { a = a / b; return a; }
+
+// clang-format on
+
+Rect2 Rect2FromSize(Vec2 pos, Vec2 size) {
+    Rect2 result = {};
+    result.min   = pos;
+    result.max   = pos + size;
+    return result;
+}
+
+Rect2 Shrink(Rect2 result, float v) {
+    result.min.x += v;
+    result.max.x -= v;
+    result.min.y += v;
+    result.max.y -= v;
+    return result;
+}
+
+Vec2 GetMid(Rect2 r) {
+    Vec2 size = GetSize(r);
+    size.x /= 2.f;
+    size.y /= 2.f;
+    Vec2 result = r.min + size;
+    return result;
+}
+
+Rect2 CutLeft(Rect2 *r, float value) {
+    float minx   = r->min.x;
+    r->min.x     = Min(r->min.x + value, r->max.x);
+    Rect2 result = {
+        {    minx, r->min.y},
+        {r->min.x, r->max.y}
+    };
+    return result;
+}
+
+Rect2 CutRight(Rect2 *r, float value) {
+    float maxx   = r->max.x;
+    r->max.x     = Max(r->min.x, r->max.x - value);
+    Rect2 result = {
+        {r->max.x, r->min.y},
+        {    maxx, r->max.y},
+    };
+    return result;
+}
+
+// Y is up
+Rect2 CutBottom(Rect2 *r, float value) {
+    float maxy   = r->max.y;
+    r->max.y     = Max(r->min.y, r->max.y - value);
+    Rect2 result = {
+        {r->min.x, r->max.y},
+        {r->max.x,     maxy},
+    };
+    return result;
+}
+
+// Y is up
+Rect2 CutTop(Rect2 *r, float value) {
+    float miny   = r->min.y;
+    r->min.y     = Min(r->min.y + value, r->max.y);
+    Rect2 result = {
+        {r->min.x,     miny},
+        {r->max.x, r->min.y},
+    };
+    return result;
+}
+
+float SafeDivide(float a, float b) {
+    if (b == 0.f) {
+        return 0.f;
+    }
+    return a / b;
+}