flag example

example/flag/main.go

@@ -0,0 +1,78 @@
+// Using the raylib library to open a window and draw a waving flag.
+//
+// Usage:
+//
+//	make example name=flag
+//	./build/flag
+package main
+
+import (
+	rl "solod.dev/raylib/libraylib"
+	"solod.dev/so/c"
+	"solod.dev/so/math"
+)
+
+var _ c.Int // for implicit int -> c.Int conversion
+
+const (
+	screenWidth  = 800
+	screenHeight = 450
+
+	halfScreenWidth  = screenWidth / 2
+	halfScreenHeight = screenHeight / 2
+
+	flagWidth  = 640
+	flagHeight = 320
+
+	halfFlagWidth  = flagWidth / 2
+	halfFlagHeight = flagHeight / 2
+
+	flagParts     = 25
+	flagPartWidth = flagWidth / flagParts
+
+	elapsedTimeFactor = 10
+	yOffsetFactor     = 10
+)
+
+func main() {
+	rl.InitWindow(screenWidth, screenHeight, "Solod Flag")
+	defer rl.CloseWindow()
+
+	rl.SetTargetFPS(60)
+
+	image := rl.GenImageColor(flagWidth, flagHeight, rl.Color{R: 13, G: 50, B: 89, A: 255})
+	rl.ImageDrawText(&image, "solod", 150, 70, 128, rl.Color{R: 242, G: 203, B: 73, A: 255})
+	rl.ImageDrawText(&image, "Go can be a better C", 150, 190, 30, rl.WHITE)
+
+	texture := rl.LoadTextureFromImage(image)
+
+	rl.UnloadImage(image)
+
+	for !rl.WindowShouldClose() {
+		elapsedTime := rl.GetTime()
+
+		rl.BeginDrawing()
+		rl.ClearBackground(rl.BLACK)
+		for i := 0; i < flagParts; i += 1 {
+			angle := float64(flagPartWidth*i) + (elapsedTime * elapsedTimeFactor)
+			rl.DrawTexturePro(
+				texture,
+				rl.Rectangle{
+					X:      float32(flagPartWidth * i),
+					Y:      0,
+					Width:  flagPartWidth,
+					Height: flagHeight,
+				},
+				rl.Rectangle{
+					X:      halfScreenWidth + float32(flagPartWidth*i),
+					Y:      halfScreenHeight + (float32(math.Sin(angle)) * yOffsetFactor),
+					Width:  flagPartWidth,
+					Height: flagHeight,
+				},
+				rl.Vector2{X: halfFlagWidth, Y: halfFlagHeight},
+				0.0,
+				rl.WHITE)
+		}
+		rl.EndDrawing()
+	}
+}