New example models/mesh_picking

examples/models/mesh_picking/main.go

@@ -0,0 +1,261 @@
+/*******************************************************************************************
+*
+*   raylib [models] example - Mesh picking in 3d mode, ground plane, triangle, mesh
+*
+*   Example originally created with raylib 1.7, last time updated with raylib 4.0
+*
+*   Example contributed by Joel Davis (@joeld42) and reviewed by Ramon Santamaria (@raysan5)
+*
+*   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) 2017-2024 Joel Davis (@joeld42) and Ramon Santamaria (@raysan5)
+*
+********************************************************************************************/
+package main
+
+import (
+	"fmt"
+	"math"
+	"unsafe"
+
+	rl "github.com/gen2brain/raylib-go/raylib"
+)
+
+const (
+	screenWidth  = 800
+	screenHeight = 450
+)
+
+// Program main entry point
+func main() {
+	rl.InitWindow(screenWidth, screenHeight, "raylib [models] example - mesh picking")
+
+	// Define the camera to look into our 3d world
+	camera := rl.Camera{
+		Position: rl.Vector3{
+			X: 20.0,
+			Y: 20.0,
+			Z: 20.0,
+		}, // Camera position
+		Target:     rl.Vector3{Y: 8.0},   // Camera looking at point
+		Up:         rl.Vector3{Y: 1.6},   // Camera up vector (rotation towards target)
+		Fovy:       45.0,                 // Camera field-of-view Y
+		Projection: rl.CameraPerspective, // Camera projection type
+	}
+	var ray rl.Ray // Picking ray
+
+	tower := rl.LoadModel("turret.obj")             // Load OBJ model
+	texture := rl.LoadTexture("turret_diffuse.png") // Load model texture
+	materials := unsafe.Slice(tower.Materials, tower.MaterialCount)
+	materials[0].GetMap(rl.MapDiffuse).Texture = texture // Set model diffuse texture
+
+	towerPos := rl.Vector3{} // Set model position
+	meshes := unsafe.Slice(tower.Meshes, tower.MeshCount)
+	towerBBox := rl.GetMeshBoundingBox(meshes[0]) // Get mesh bounding box
+
+	// Ground quad
+	g0 := rl.Vector3{
+		X: -50.0,
+		Z: -50.0,
+	}
+	g1 := rl.Vector3{
+		X: -50.0,
+		Z: 50.0,
+	}
+	g2 := rl.Vector3{
+		X: 50.0,
+		Z: 50.0,
+	}
+	g3 := rl.Vector3{
+		X: 50.0,
+		Z: -50.0,
+	}
+
+	// Test triangle
+	ta := rl.Vector3{
+		X: -25.0,
+		Y: 0.5,
+	}
+	tb := rl.Vector3{
+		X: -4.0,
+		Y: 2.5,
+		Z: 1.0,
+	}
+	tc := rl.Vector3{
+		X: -8.0,
+		Y: 6.5,
+	}
+
+	bary := rl.Vector3{}
+
+	// Test sphere
+	sp := rl.Vector3{
+		X: -30.0,
+		Y: 5.0,
+		Z: 5.0,
+	}
+	sr := float32(4.0)
+
+	rl.SetTargetFPS(60) // Set our game to run at 60 frames-per-second
+	// Main game loop
+	for !rl.WindowShouldClose() { // Detect window close button or ESC key
+		// Update
+		if rl.IsCursorHidden() {
+			rl.UpdateCamera(&camera, rl.CameraFirstPerson) // Update camera
+		}
+		// Toggle camera controls
+		if rl.IsMouseButtonPressed(rl.MouseButtonRight) {
+			if rl.IsCursorHidden() {
+				rl.EnableCursor()
+			} else {
+				rl.DisableCursor()
+			}
+		}
+
+		// Display information about the closest hit
+		collision := rl.RayCollision{
+			Distance: math.MaxFloat32,
+			Hit:      false,
+		}
+		hitObjectName := "None"
+		cursorColor := rl.White
+
+		// Get ray and test against objects
+		// See issue : https://github.com/gen2brain/raylib-go/issues/457
+		//ray = rl.GetScreenToWorldRay(rl.GetMousePosition(), camera)
+		ray = rl.GetMouseRay(rl.GetMousePosition(), camera)
+
+		// Check ray collision against ground quad
+		groundHitInfo := rl.GetRayCollisionQuad(ray, g0, g1, g2, g3)
+
+		if (groundHitInfo.Hit) && (groundHitInfo.Distance < collision.Distance) {
+			collision = groundHitInfo
+			cursorColor = rl.Green
+			hitObjectName = "Ground"
+		}
+
+		// Check ray collision against test triangle
+		triHitInfo := rl.GetRayCollisionTriangle(ray, ta, tb, tc)
+
+		if (triHitInfo.Hit) && (triHitInfo.Distance < collision.Distance) {
+			collision = triHitInfo
+			cursorColor = rl.Purple
+			hitObjectName = "Triangle"
+
+			bary = rl.Vector3Barycenter(collision.Point, ta, tb, tc)
+		}
+
+		// Check ray collision against test sphere
+		sphereHitInfo := rl.GetRayCollisionSphere(ray, sp, sr)
+
+		if (sphereHitInfo.Hit) && (sphereHitInfo.Distance < collision.Distance) {
+			collision = sphereHitInfo
+			cursorColor = rl.Orange
+			hitObjectName = "Sphere"
+		}
+
+		// Check ray collision against bounding box first, before trying the full ray-mesh test
+		boxHitInfo := rl.GetRayCollisionBox(ray, towerBBox)
+
+		if (boxHitInfo.Hit) && (boxHitInfo.Distance < collision.Distance) {
+			collision = boxHitInfo
+			cursorColor = rl.Orange
+			hitObjectName = "Box"
+
+			// Check ray collision against model meshes
+			meshHitInfo := rl.RayCollision{}
+			for m := int32(0); m < tower.MeshCount; m++ {
+				// NOTE: We consider the model.transform for the collision check, but
+				// it can be checked against any transform Matrix, used when checking against same
+				// model drawn multiple times with multiple transforms
+				meshHitInfo = rl.GetRayCollisionMesh(ray, meshes[m], tower.Transform)
+				if meshHitInfo.Hit {
+					// Save the closest hit mesh
+					if (!collision.Hit) || (collision.Distance > meshHitInfo.Distance) {
+						collision = meshHitInfo
+					}
+
+					break // Stop once one mesh collision is detected, the colliding mesh is m
+				}
+			}
+
+			if meshHitInfo.Hit {
+				collision = meshHitInfo
+				cursorColor = rl.Orange
+				hitObjectName = "Mesh"
+			}
+		}
+
+		// Draw
+		rl.BeginDrawing()
+		rl.ClearBackground(rl.RayWhite)
+		rl.BeginMode3D(camera)
+
+		// Draw the tower
+		// WARNING: If scale is different from 1.0f,
+		// not considered by GetRayCollisionModel()
+		rl.DrawModel(tower, towerPos, 1.0, rl.White)
+
+		// Draw the test triangle
+		rl.DrawLine3D(ta, tb, rl.Purple)
+		rl.DrawLine3D(tb, tc, rl.Purple)
+		rl.DrawLine3D(tc, ta, rl.Purple)
+
+		// Draw the test sphere
+		rl.DrawSphereWires(sp, sr, 8, 8, rl.Purple)
+
+		// Draw the mesh bbox if we hit it
+		if boxHitInfo.Hit {
+			rl.DrawBoundingBox(towerBBox, rl.Lime)
+		}
+
+		// If we hit something, draw the cursor at the hit point
+		if collision.Hit {
+			rl.DrawCube(collision.Point, 0.3, 0.3, 0.3, cursorColor)
+			rl.DrawCubeWires(collision.Point, 0.3, 0.3, 0.3, rl.Red)
+
+			normalEnd := rl.Vector3{}
+			normalEnd.X = collision.Point.X + collision.Normal.X
+			normalEnd.Y = collision.Point.Y + collision.Normal.Y
+			normalEnd.Z = collision.Point.Z + collision.Normal.Z
+
+			rl.DrawLine3D(collision.Point, normalEnd, rl.Red)
+		}
+
+		rl.DrawRay(ray, rl.Maroon)
+		rl.DrawGrid(10, 10.0)
+
+		rl.EndMode3D()
+
+		// Draw some debug GUI text
+		rl.DrawText(fmt.Sprintf("Hit Object: %s", hitObjectName), 10, 50, 10, rl.Black)
+
+		if collision.Hit {
+			ypos := int32(70)
+			rl.DrawText(fmt.Sprintf("Distance: %3.2f", collision.Distance), 10, ypos, 10, rl.Black)
+			rl.DrawText(Vec2Str("Hit Pos : %3.2f %3.2f %3.2f", collision.Point), 10, ypos+15, 10, rl.Black)
+			rl.DrawText(Vec2Str("Hit Norm: %3.2f %3.2f %3.2f", collision.Normal), 10, ypos+30, 10, rl.Black)
+			if triHitInfo.Hit && hitObjectName == "Triangle" {
+				rl.DrawText(Vec2Str("Barycenter: %3.2f %3.2f %3.2f", bary), 10, ypos+45, 10, rl.Black)
+			}
+		}
+
+		rl.DrawText("Right click mouse to toggle camera controls", 10, 430, 10, rl.Gray)
+		rl.DrawText("(c) Turret 3D model by Alberto Cano", screenWidth-200, screenHeight-20, 10, rl.Gray)
+
+		rl.DrawFPS(10, 10)
+
+		rl.EndDrawing()
+	}
+
+	// De-Initialization
+	rl.UnloadModel(tower)     // Unload model
+	rl.UnloadTexture(texture) // Unload texture
+
+	rl.CloseWindow() // Close window and OpenGL context
+}
+
+func Vec2Str(format string, vec rl.Vector3) string {
+	return fmt.Sprintf(format, vec.X, vec.Y, vec.Z)
+}