From d665d89c5f35667aa8c1be727426ab8991ac4e99 Mon Sep 17 00:00:00 2001
From: Travis Martin <tjmartin2003@gmail.com>
Date: Sun, 8 Oct 2023 00:47:29 -0500
Subject: [PATCH] `colorMask`.

---
 package.json               |  1 +
 src/constants/constants.ts |  8 ++++++++
 src/core/Context.ts        | 35 ++++++++++++++++++++++++++++++++++-
 src/index.ts               |  1 +
 src/types/ColorMask.ts     | 14 ++++++++++++++
 5 files changed, 58 insertions(+), 1 deletion(-)
 create mode 100644 src/types/ColorMask.ts

diff --git a/package.json b/package.json
index a6e1daad..7215cfd1 100644
--- a/package.json
+++ b/package.json
@@ -80,6 +80,7 @@
 		"#BlendFunctionSet": "./dist/types/BlendFunctionSet.js",
 		"#Canvas": "./dist/types/Canvas.js",
 		"#Color": "./dist/types/Color.js",
+		"#ColorMask": "./dist/types/ColorMask.js",
 		"#FloatTypedArray": "./dist/types/FloatTypedArray.js",
 		"#IntTypedArray": "./dist/types/IntTypedArray.js",
 		"#TypedArray": "./dist/types/TypedArray.js",
diff --git a/src/constants/constants.ts b/src/constants/constants.ts
index 6d6898ab..7580e7c0 100644
--- a/src/constants/constants.ts
+++ b/src/constants/constants.ts
@@ -235,3 +235,11 @@ export const DEPTH_BUFFER_BIT = 0x00000100;
  * @internal
  */
 export const STENCIL_BUFFER_BIT = 0x00000400;
+
+/**
+ * The mask that specifies which components to enable or disable when
+ * rendering to a framebuffer.
+ * @see [`getParameter`](https://developer.mozilla.org/en-US/docs/Web/API/WebGLRenderingContext/getParameter)
+ * @internal
+ */
+export const COLOR_WRITEMASK = 0x0c23;
diff --git a/src/core/Context.ts b/src/core/Context.ts
index 65c9a236..aec33902 100644
--- a/src/core/Context.ts
+++ b/src/core/Context.ts
@@ -13,7 +13,8 @@ import {
 	STENCIL_CLEAR_VALUE,
 	COLOR_BUFFER_BIT,
 	DEPTH_BUFFER_BIT,
-	STENCIL_BUFFER_BIT
+	STENCIL_BUFFER_BIT,
+	COLOR_WRITEMASK
 } from "#constants";
 import ApiInterface from "#ApiInterface";
 import type { Canvas } from "#Canvas";
@@ -27,6 +28,7 @@ import type BlendFunctionFullSet from "#BlendFunctionFullSet";
 import type BlendFunction from "#BlendFunction";
 import ErrorCode from "#ErrorCode";
 import WebglError from "#WebglError";
+import type ColorMask from "#ColorMask";
 
 /**
  * A WebGL2 rendering context.
@@ -541,4 +543,35 @@ export default class Context extends ApiInterface {
 		this.gl.clearStencil(value);
 		this.clearStencilCache = value;
 	}
+
+	/**
+	 * The mask that specifies which components to enable or disable when
+	 * rendering to a framebuffer.
+	 * @see [`colorMask`](https://developer.mozilla.org/en-US/docs/Web/API/WebGLRenderingContext/colorMask)
+	 * @internal
+	 */
+	private colorMaskCache?: ColorMask;
+
+	/**
+	 * The mask that specifies which components to enable or disable when
+	 * rendering to a framebuffer.
+	 * @see [`colorMask`](https://developer.mozilla.org/en-US/docs/Web/API/WebGLRenderingContext/colorMask)
+	 */
+	public get colorMask(): ColorMask {
+		if (typeof this.colorMaskCache == "undefined") {
+			this.colorMaskCache = this.gl.getParameter(COLOR_WRITEMASK);
+		}
+
+		return this.colorMaskCache!;
+	}
+
+	/**
+	 * The mask that specifies which components to enable or disable when
+	 * rendering to a framebuffer.
+	 * @see [`colorMask`](https://developer.mozilla.org/en-US/docs/Web/API/WebGLRenderingContext/colorMask)
+	 */
+	public set colorMask(value: ColorMask) {
+		this.gl.colorMask(value[0], value[1], value[2], value[3]);
+		this.colorMaskCache = value;
+	}
 }
diff --git a/src/index.ts b/src/index.ts
index 1fd27ef5..e66cb986 100644
--- a/src/index.ts
+++ b/src/index.ts
@@ -19,6 +19,7 @@ export type { default as BlendFunctionFullSet } from "#BlendFunctionFullSet";
 export type { default as BlendFunctionSet } from "#BlendFunctionSet";
 export type { Canvas } from "#Canvas";
 export type { default as Color } from "#Color";
+export type { default as ColorMask } from "#ColorMask";
 export type { FloatTypedArray } from "#FloatTypedArray";
 export type { TypedArray } from "#TypedArray";
 export type { IntTypedArray } from "#IntTypedArray";
diff --git a/src/types/ColorMask.ts b/src/types/ColorMask.ts
new file mode 100644
index 00000000..3f220f0f
--- /dev/null
+++ b/src/types/ColorMask.ts
@@ -0,0 +1,14 @@
+/** A color mask. */
+export default interface ColorMask {
+	/** Whether to write to the red component. */
+	0: boolean;
+
+	/** Whether to write to the green component. */
+	1: boolean;
+
+	/** Whether to write to the blue component. */
+	2: boolean;
+
+	/** Whether to write to the alpha component. */
+	3: boolean;
+}