Fixed example that differed : models/billboard

examples/models/billboard/main.go

@@ -1,13 +1,26 @@
-package main
+/*******************************************************************************************
+*
+*   raylib [models] example - Drawing billboards
+*
+*   Example originally created with raylib 1.3, last time updated with raylib 3.5
+*
+*   Example licensed under an unmodified zlib/libpng license, which is an OSI-certified,
+*   BSD-like license that allows static linking with closed source software
+*
+*   Copyright (c) 2015-2024 Ramon Santamaria (@raysan5)
+*
+********************************************************************************************/package main
 
 import (
 	rl "github.com/gen2brain/raylib-go/raylib"
 )
 
-func main() {
-	screenWidth := int32(800)
-	screenHeight := int32(450)
+const (
+	screenWidth  = 800
+	screenHeight = 450
+)
 
+func main() {
 	rl.InitWindow(screenWidth, screenHeight, "raylib [models] example - drawing billboards")
 
 	camera := rl.Camera{}
@@ -17,26 +30,61 @@ func main() {
 	camera.Fovy = 45.0
 	camera.Projection = rl.CameraPerspective
 
-	bill := rl.LoadTexture("billboard.png")      // Our texture billboard
-	billPosition := rl.NewVector3(0.0, 2.0, 0.0) // Position where draw billboard
+	bill := rl.LoadTexture("billboard.png")              // Our texture billboard
+	billPositionStatic := rl.NewVector3(0.0, 2.0, 0.0)   // Position of static billboard
+	billPositionRotating := rl.NewVector3(1.0, 2.0, 1.0) // Position of rotating billboard
+
+	// Entire billboard texture, source is used to take a segment from a larger texture.
+	source := rl.Rectangle{
+		Width:  float32(bill.Width),
+		Height: float32(bill.Height),
+	}
+
+	// NOTE: Billboard locked on axis-Y
+	billUp := rl.Vector3{Y: 1.0}
+
+	// Set the height of the rotating billboard to 1.0 with the aspect ratio fixed
+	size := rl.Vector2{
+		X: source.Width / source.Height,
+		Y: 1.0,
+	}
+
+	// Rotate around origin
+	// Here we choose to rotate around the image center
+	origin := rl.Vector2Scale(size, 0.5)
+
+	// Distance is needed for the correct billboard draw order
+	// Larger distance (further away from the camera) should be drawn prior to smaller distance.
+	var distanceStatic, distanceRotating, rotation float32
 
 	rl.SetTargetFPS(60)
 
 	for !rl.WindowShouldClose() {
+		// Update
 		rl.UpdateCamera(&camera, rl.CameraOrbital) // Update camera with orbital camera mode
 
+		rotation += 0.4
+		distanceStatic = rl.Vector3Distance(camera.Position, billPositionStatic)
+		distanceRotating = rl.Vector3Distance(camera.Position, billPositionRotating)
+
+		// Draw
 		rl.BeginDrawing()
-
 		rl.ClearBackground(rl.RayWhite)
-
 		rl.BeginMode3D(camera)
 
 		rl.DrawGrid(10, 1.0) // Draw a grid
 
-		rl.DrawBillboard(camera, bill, billPosition, 2.0, rl.White)
+		// Draw order matters!
+		if distanceStatic > distanceRotating {
+			rl.DrawBillboard(camera, bill, billPositionStatic, 2.0, rl.White)
+			rl.DrawBillboardPro(camera, bill, source, billPositionRotating, billUp, size, origin, rotation, rl.White)
+		} else {
+			rl.DrawBillboardPro(camera, bill, source, billPositionRotating, billUp, size, origin, rotation, rl.White)
+			rl.DrawBillboard(camera, bill, billPositionStatic, 2.0, rl.White)
+		}
 
 		rl.EndMode3D()
-
+		rl.DrawFPS(10, 10)
 		rl.EndDrawing()
 	}