Add support for AgX tone mapping

Closes #555

src/effects/ToneMappingEffect.js

@@ -1,6 +1,7 @@
 import { LinearMipmapLinearFilter, Uniform, WebGLRenderTarget } from "three";
 import { AdaptiveLuminancePass, LuminancePass } from "../passes/index.js";
 import { BlendFunction, ToneMappingMode } from "../enums/index.js";
+import { validateToneMappingMode } from "../utils/index.js";
 import { Effect } from "./Effect.js";
 
 import fragmentShader from "./glsl/tone-mapping.frag";
@@ -25,7 +26,7 @@ export class ToneMappingEffect extends Effect {
 	 * @param {Object} [options] - The options.
 	 * @param {BlendFunction} [options.blendFunction=BlendFunction.SRC] - The blend function of this effect.
 	 * @param {Boolean} [options.adaptive=false] - Deprecated. Use mode instead.
-	 * @param {ToneMappingMode} [options.mode=ToneMappingMode.ACES_FILMIC] - The tone mapping mode.
+	 * @param {ToneMappingMode} [options.mode=ToneMappingMode.AGX] - The tone mapping mode.
 	 * @param {Number} [options.resolution=256] - The resolution of the luminance texture. Must be a power of two.
 	 * @param {Number} [options.maxLuminance=4.0] - Deprecated. Same as whitePoint.
 	 * @param {Number} [options.whitePoint=4.0] - The white point.
@@ -38,7 +39,7 @@ export class ToneMappingEffect extends Effect {
 	constructor({
 		blendFunction = BlendFunction.SRC,
 		adaptive = false,
-		mode = adaptive ? ToneMappingMode.REINHARD2_ADAPTIVE : ToneMappingMode.ACES_FILMIC,
+		mode = adaptive ? ToneMappingMode.REINHARD2_ADAPTIVE : ToneMappingMode.AGX,
 		resolution = 256,
 		maxLuminance = 4.0,
 		whitePoint = maxLuminance,
@@ -123,6 +124,8 @@ export class ToneMappingEffect extends Effect {
 			this.defines.clear();
 			this.defines.set("TONE_MAPPING_MODE", value.toFixed(0));
 
+			value = validateToneMappingMode(value);
+
 			// Use one of the built-in tone mapping operators.
 			switch(value) {
 
@@ -138,6 +141,10 @@ export class ToneMappingEffect extends Effect {
 					this.defines.set("toneMapping(texel)", "ACESFilmicToneMapping(texel)");
 					break;
 
+				case ToneMappingMode.AGX:
+					this.defines.set("toneMapping(texel)", "AgXToneMapping(texel)");
+					break;
+
 				default:
 					this.defines.set("toneMapping(texel)", "texel");
 					break;

src/effects/glsl/tone-mapping.frag

@@ -10,6 +10,8 @@ uniform float whitePoint;
 
 #if TONE_MAPPING_MODE == 1 || TONE_MAPPING_MODE == 2
 
+	// Reinhard 2
+
 	uniform float middleGrey;
 
 	#if TONE_MAPPING_MODE == 2
@@ -48,9 +50,10 @@ uniform float whitePoint;
 
 	}
 
-#elif TONE_MAPPING_MODE == 5
+#elif TONE_MAPPING_MODE == 3
+
+	// Uncharted 2: http://filmicworlds.com/blog/filmic-tonemapping-operators
 
-	// http://filmicworlds.com/blog/filmic-tonemapping-operators
 	#define A 0.15
 	#define B 0.50
 	#define C 0.10
@@ -79,7 +82,7 @@ void mainImage(const in vec4 inputColor, const in vec2 uv, out vec4 outputColor)
 
 		outputColor = vec4(Reinhard2ToneMapping(inputColor.rgb), inputColor.a);
 
-	#elif TONE_MAPPING_MODE == 5
+	#elif TONE_MAPPING_MODE == 3
 
 		outputColor = vec4(Uncharted2ToneMapping(inputColor.rgb), inputColor.a);
 

src/enums/ToneMappingMode.js

@@ -6,15 +6,17 @@
  * @property {Number} REINHARD2 - Modified Reinhard tone mapping.
  * @property {Number} REINHARD2_ADAPTIVE - Simulates the optic nerve responding to the amount of light it is receiving.
  * @property {Number} OPTIMIZED_CINEON - Optimized filmic operator by Jim Hejl and Richard Burgess-Dawson.
+ * @property {Number} UNCHARTED2 - Uncharted 2 tone mapping. http://filmicworlds.com/blog/filmic-tonemapping-operators.
  * @property {Number} ACES_FILMIC - ACES tone mapping with a scale of 1.0/0.6.
- * @property {Number} UNCHARTED2 - Uncharted 2 tone mapping. http://filmicworlds.com/blog/filmic-tonemapping-operators
+ * @property {Number} AGX - Filmic tone mapping. Requires three r160 or higher. https://github.com/EaryChow/AgX.
  */
 
 export const ToneMappingMode = {
 	REINHARD: 0,
 	REINHARD2: 1,
 	REINHARD2_ADAPTIVE: 2,
-	OPTIMIZED_CINEON: 3,
-	ACES_FILMIC: 4,
-	UNCHARTED2: 5
+	UNCHARTED2: 3,
+	OPTIMIZED_CINEON: 4,
+	ACES_FILMIC: 5,
+	AGX: 6
 };

src/utils/BackCompat.js

@@ -1,5 +1,5 @@
 import { LinearEncoding, REVISION, sRGBEncoding } from "three";
-import { LinearSRGBColorSpace, SRGBColorSpace } from "../enums/index.js";
+import { LinearSRGBColorSpace, SRGBColorSpace, ToneMappingMode } from "../enums/index.js";
 
 const revision = Number(REVISION.replace(/\D+/g, ""));
 const useColorSpace = revision >= 152;
@@ -128,3 +128,24 @@ export function updateVertexShader(vertexShader) {
 	return vertexShader;
 
 }
+
+/**
+ * Validates the given tone mapping mode against the current version of three.
+ *
+ * @param {ToneMappingMode} mode - A tone mapping mode.
+ * @return {ToneMappingMode} The validated tone mapping mode.
+ * @ignore
+ */
+
+export function validateToneMappingMode(mode) {
+
+	if(revision < 160 && mode === ToneMappingMode.AGX) {
+
+		console.warn("AgX requires three r160 or higher, falling back to ACES filmic");
+		mode = ToneMappingMode.ACES_FILMIC;
+
+	}
+
+	return mode;
+
+}