69 lines
1.8 KiB
Go
69 lines
1.8 KiB
Go
package main
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import (
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"fmt"
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"math"
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rl "github.com/gen2brain/raylib-go/raylib"
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)
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const HEIGHT = 600
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const WIDTH = 800
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func main() {
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fmt.Println("hello world")
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rl.SetConfigFlags(rl.FlagMsaa4xHint)
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rl.InitWindow(WIDTH, HEIGHT, "raylib [core] example - basic window")
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defer rl.CloseWindow()
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// rl.SetTargetFPS(60)
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rl.BeginDrawing()
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rl.ClearBackground(rl.RayWhite)
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rl.EndDrawing()
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var innerCircleRadius float32 = HEIGHT/2
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var outerCircleRadius float32 = innerCircleRadius/2
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trace := true
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for !rl.WindowShouldClose() {
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rl.BeginDrawing()
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if !trace {
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rl.ClearBackground(rl.RayWhite)
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}
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if rl.IsKeyPressed(rl.KeySpace) {
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trace = !trace
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}
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angle := float64(rl.GetTime() * 1)
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center := rl.NewVector2(WIDTH/2, HEIGHT/2)
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outerCircle := rl.NewVector2(float32(math.Cos(angle)), float32(math.Sin(angle)))
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outerCircle = rl.Vector2Scale(outerCircle, innerCircleRadius - outerCircleRadius)
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outerCircle = rl.Vector2Add(outerCircle, center)
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if !trace {
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// outer circle
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rl.DrawCircleV(outerCircle, outerCircleRadius, rl.Black)
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rl.DrawCircleV(outerCircle, outerCircleRadius-1, rl.RayWhite)
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rl.DrawLineV(outerCircle, center, rl.Black)
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}
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var tipSize float32 = 6
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if trace {
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tipSize = 2
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}
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// tip
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angle *= -7.3
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tip := rl.NewVector2(float32(math.Cos(angle)), float32(math.Sin(angle)))
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tip = rl.Vector2Scale(tip, outerCircleRadius)
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tip = rl.Vector2Add(tip, outerCircle)
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rl.DrawCircleV(tip, tipSize, rl.Blue)
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if !trace {
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// inner circle
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rl.DrawCircleLines(WIDTH/2, HEIGHT/2, innerCircleRadius, rl.Black)
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}
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rl.EndDrawing()
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}
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}
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