Add textures

src/graphics/graphics-library/texture/palette-texture.ts

@@ -0,0 +1,29 @@
+import { vec3, vec4 } from 'gl-matrix';
+import { UniversalRenderingContext } from '../universal-rendering-context';
+import { Texture } from './texture';
+
+/** @internal */
+export class PaletteTexture extends Texture {
+  constructor(gl: UniversalRenderingContext, private readonly paletteSize: number) {
+    super(gl, 1);
+  }
+
+  public setPalette(colors: Array<vec3 | vec4>) {
+    const canvas = document.createElement('canvas');
+    canvas.width = this.paletteSize;
+    canvas.height = 1;
+
+    const ctx = canvas.getContext('2d')!;
+    const imageData = ctx.createImageData(this.paletteSize, 1);
+
+    colors.forEach((c, i) => {
+      imageData.data[4 * i + 0] = c[0] * 255;
+      imageData.data[4 * i + 1] = c[1] * 255;
+      imageData.data[4 * i + 2] = c[2] * 255;
+      imageData.data[4 * i + 3] = c.length == 4 ? c[3] * 255 : 255;
+    });
+    ctx.putImageData(imageData, 0, 0);
+
+    this.setImage(canvas);
+  }
+}