Lighting optimizations.

Lighting is now done on a per-triangle basis rather than a per-vertex basis, as Sun lights color all vertices the same (as they all belong to the same triangle, which has just one normal). Point lights are also optimized - rather than transforming each vertex by the model's transform, it's faster to transform the point light's position by the model's inverted transform. Light.Light() returns an array of 9 floats, indicating the R, G, and B values for the light for each vertex of a given triangle. Adding toggle-able lighting in the lighting example.
SolarLune · Jan 7, 2022 · 59cf471 · 59cf471
1 parent 8046ef3
commit 59cf471
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Showing 4 changed files with 159 additions and 98 deletions.
diff --git a/camera.go b/camera.go
@@ -27,6 +27,8 @@ type DebugInfo struct {
 	TotalObjects     int // Total number of objects
 	DrawnTris        int // Number of drawn triangles, excluding those hidden from backface culling
 	TotalTris        int // Total number of triangles
+	LightCount       int // Total number of lights
+	ActiveLightCount int // Total active number of lights
 }
 
 // Camera represents a camera (where you look from) in Tetra3D.
@@ -281,7 +283,8 @@ func (camera *Camera) Clear() {
 	camera.DebugInfo.TotalObjects = 0
 	camera.DebugInfo.TotalTris = 0
 	camera.DebugInfo.DrawnTris = 0
-
+	camera.DebugInfo.LightCount = 0
+	camera.DebugInfo.ActiveLightCount = 0
 }
 
 // RenderNodes renders all nodes starting with the provided rootNode using the Scene's properties (fog, for example).
@@ -332,9 +335,13 @@ func (camera *Camera) Render(scene *Scene, models ...*Model) {
 	if scene.LightingOn {
 
 		for _, l := range scene.Root.ChildrenRecursive() {
-			if light, isLight := l.(Light); isLight && light.isOn() {
-				lights = append(lights, light)
-				light.begin()
+			if light, isLight := l.(Light); isLight {
+				camera.DebugInfo.LightCount++
+				if light.isOn() {
+					lights = append(lights, light)
+					light.beginRender()
+					camera.DebugInfo.ActiveLightCount++
+				}
 			}
 		}
 
@@ -544,58 +551,72 @@ func (camera *Camera) Render(scene *Scene, models ...*Model) {
 
 		index := 0
 
-		modelTrans := model.Transform()
-
-		lighting := scene.LightingOn
-		if model.Mesh.Material != nil {
-			lighting = scene.LightingOn && model.Mesh.Material.EnableLighting
-		}
-
 		for _, tri := range triList[:vertexListIndex/3] {
 
 			for _, vert := range tri.Vertices {
 
 				// Vertex colors
 
-				if lighting {
+				vertexList[index].ColorR = vert.Color.R
+				vertexList[index].ColorG = vert.Color.G
+				vertexList[index].ColorB = vert.Color.B
+
+				vertexList[index].ColorA = vert.Color.A
+
+				vertexList[index].SrcX = float32(vert.UV[0] * srcW)
+
+				// We do 1 - v here (aka Y in texture coordinates) because 1.0 is the top of the texture while 0 is the bottom in UV coordinates,
+				// but when drawing textures 0 is the top, and the sourceHeight is the bottom.
+				vertexList[index].SrcY = float32((1 - vert.UV[1]) * srcH)
 
-					t := time.Now()
+				index++
 
-					r := float32(0)
-					g := float32(0)
-					b := float32(0)
+			}
 
-					for _, light := range lights {
-						lr, lg, lb := light.Light(vert, modelTrans)
-						r += lr
-						g += lg
-						b += lb
-					}
+		}
 
-					camera.DebugInfo.lightTime += time.Since(t)
+		lighting := scene.LightingOn
+		if model.Mesh.Material != nil {
+			lighting = scene.LightingOn && model.Mesh.Material.EnableLighting
+		}
+
+		if lighting {
+
+			index = 0
+
+			t := time.Now()
+
+			for _, light := range lights {
+				light.beginModel(model)
+			}
+
+			lightColors := [9]float32{}
 
-					vertexList[index].ColorR = vert.Color.R * r
-					vertexList[index].ColorG = vert.Color.G * g
-					vertexList[index].ColorB = vert.Color.B * b
+			for _, tri := range triList[:vertexListIndex/3] {
 
-				} else {
-					vertexList[index].ColorR = vert.Color.R
-					vertexList[index].ColorG = vert.Color.G
-					vertexList[index].ColorB = vert.Color.B
+				for i := range lightColors {
+					lightColors[i] = 0
 				}
 
-				vertexList[index].ColorA = vert.Color.A
+				for _, light := range lights {
+					for i, v := range light.Light(tri) {
+						lightColors[i] += v
+					}
+				}
 
-				vertexList[index].SrcX = float32(vert.UV[0] * srcW)
+				for vertIndex := range tri.Vertices {
 
-				// We do 1 - v here (aka Y in texture coordinates) because 1.0 is the top of the texture while 0 is the bottom in UV coordinates,
-				// but when drawing textures 0 is the top, and the sourceHeight is the bottom.
-				vertexList[index].SrcY = float32((1 - vert.UV[1]) * srcH)
+					vertexList[index].ColorR *= lightColors[(vertIndex)*3]
+					vertexList[index].ColorG *= lightColors[(vertIndex)*3+1]
+					vertexList[index].ColorB *= lightColors[(vertIndex)*3+2]
+					index++
 
-				index++
+				}
 
 			}
 
+			camera.DebugInfo.lightTime += time.Since(t)
+
 		}
 
 		var img *ebiten.Image
@@ -670,10 +691,12 @@ func (camera *Camera) DrawDebugText(screen *ebiten.Image, textScale float64) {
 	lt := fmt.Sprintf("%.2fms", float32(m)/1000)
 
 	text.DrawWithOptions(screen, fmt.Sprintf(
-		"FPS: %f\nTotal frame time: %s\nSkinned mesh animation time: %s\nLighting time:%s\nRendered objects:%d/%d\nRendered triangles: %d/%d",
+		"FPS: %f\nTotal frame time: %s\nSkinned mesh animation time: %s\nActive Lights:%d/%d\nLighting time:%s\nRendered objects:%d/%d\nRendered triangles: %d/%d",
 		ebiten.CurrentFPS(),
 		ft,
 		at,
+		camera.DebugInfo.ActiveLightCount,
+		camera.DebugInfo.LightCount,
 		lt,
 		camera.DebugInfo.DrawnObjects,
 		camera.DebugInfo.TotalObjects,

diff --git a/examples/lighting/main.go b/examples/lighting/main.go
@@ -185,6 +185,10 @@ func (g *Game) Update() error {
 		g.DrawDebugDepth = !g.DrawDebugDepth
 	}
 
+	if inpututil.IsKeyJustPressed(ebiten.Key1) {
+		g.Scene.LightingOn = !g.Scene.LightingOn
+	}
+
 	return err
 }
 
@@ -211,8 +215,8 @@ func (g *Game) Draw(screen *ebiten.Image) {
 
 	if g.DrawDebugText {
 		g.Camera.DrawDebugText(screen, 1)
-		txt := "F1 to toggle this text\nWASD: Move, Mouse: Look\nThis example simply shows dynamic vertex-based lighting.\nF5: Toggle depth debug view\nF4: Toggle fullscreen\nESC: Quit"
-		text.Draw(screen, txt, basicfont.Face7x13, 0, 100, color.RGBA{255, 0, 0, 255})
+		txt := "F1 to toggle this text\nWASD: Move, Mouse: Look\nThis example simply shows dynamic vertex-based lighting.\n1 Key: Toggle lighting\nF5: Toggle depth debug view\nF4: Toggle fullscreen\nESC: Quit"
+		text.Draw(screen, txt, basicfont.Face7x13, 0, 150, color.RGBA{255, 0, 0, 255})
 	}
 }