porting new examples to Go from raylib.com/examples.html

examples/shapes/rectangle_scaling/main.go

@@ -0,0 +1,78 @@
+package main
+
+import (
+	rl "github.com/gen2brain/raylib-go/raylib"
+)
+
+var (
+	mouseScaleMarkSize              = float32(12)
+	rec                             = rl.NewRectangle(100, 100, 200, 80)
+	mouseScaleReady, MouseScaleMode = false, false
+)
+
+func main() {
+	screenWidth := int32(1280)
+	screenHeight := int32(720)
+
+	rl.InitWindow(screenWidth, screenHeight, "raylib [shapes] example - rectangle scaling mouse")
+
+	rl.SetTargetFPS(60)
+
+	rl.SetMousePosition(0, 0)
+
+	for !rl.WindowShouldClose() {
+
+		mousePos := rl.GetMousePosition()
+
+		if rl.CheckCollisionPointRec(mousePos, rl.NewRectangle(rec.X+rec.Width-mouseScaleMarkSize, rec.Y+rec.Height-mouseScaleMarkSize, mouseScaleMarkSize, mouseScaleMarkSize)) {
+			mouseScaleReady = true
+			if rl.IsMouseButtonPressed(rl.MouseLeftButton) {
+				MouseScaleMode = true
+			}
+		} else {
+			mouseScaleReady = false
+		}
+
+		if MouseScaleMode {
+
+			mouseScaleReady = true
+			rec.Width = mousePos.X - rec.X
+			rec.Height = mousePos.Y - rec.Y
+
+			// CHECK MIN MAX REC SIZES
+			if rec.Width < mouseScaleMarkSize {
+				rec.Width = rec.Width
+			}
+			if rec.Height < mouseScaleMarkSize {
+				rec.Height = rec.Width
+			}
+			if rec.Width > (float32(rl.GetScreenWidth()) - rec.X) {
+				rec.Width = float32(rl.GetScreenWidth()) - rec.X
+			}
+			if rec.Height > (float32(rl.GetScreenHeight()) - rec.Y) {
+				rec.Height = float32(rl.GetScreenHeight()) - rec.Y
+			}
+			if rl.IsMouseButtonReleased(rl.MouseLeftButton) {
+				MouseScaleMode = false
+			}
+
+		}
+
+		rl.BeginDrawing()
+		rl.ClearBackground(rl.RayWhite)
+
+		rl.DrawText("Scale rectangle dragging from bottom-right corner!", 10, 10, 20, rl.Black)
+
+		rl.DrawRectangleRec(rec, rl.Fade(rl.Green, 0.5))
+
+		if mouseScaleReady {
+			rl.DrawRectangleLinesEx(rec, 1, rl.Red)
+			rl.DrawTriangle(rl.NewVector2(rec.X+rec.Width-mouseScaleMarkSize, rec.Y+rec.Height), rl.NewVector2(rec.X+rec.Width, rec.Y+rec.Height), rl.NewVector2(rec.X+rec.Width, rec.Y+rec.Height-mouseScaleMarkSize), rl.Red)
+		}
+
+		rl.EndDrawing()
+
+	}
+
+	rl.CloseWindow()
+}