From f2a7107a676eafbb54b1ba159839c304e1a5b7e6 Mon Sep 17 00:00:00 2001
From: schmelczerandras <schmelczer.andras@simonyi.bme.hu>
Date: Mon, 19 Oct 2020 11:59:09 +0200
Subject: [PATCH] Fix rendering for WebGL2 GPU-s lacking
 OES_texture_float_linear

---
 .../texture/distance-texture.ts               | 35 +++++++------------
 1 file changed, 12 insertions(+), 23 deletions(-)

diff --git a/src/graphics/graphics-library/texture/distance-texture.ts b/src/graphics/graphics-library/texture/distance-texture.ts
index b7ada47..81fa51e 100644
--- a/src/graphics/graphics-library/texture/distance-texture.ts
+++ b/src/graphics/graphics-library/texture/distance-texture.ts
@@ -1,5 +1,6 @@
 import { vec2 } from 'gl-matrix';
-import { enableExtension } from '../helper/enable-extension';
+import { tryEnableExtension } from '../helper/enable-extension';
+import { UniversalRenderingContext } from '../universal-rendering-context';
 import { Texture } from './texture';
 import { FilteringOptions } from './texture-options';
 
@@ -7,31 +8,19 @@ import { FilteringOptions } from './texture-options';
 export class DistanceTexture extends Texture {
   public static readonly textureUnitId = 1;
 
-  private floatEnabled = false;
   private floatLinearEnabled = false;
 
-  constructor(gl: WebGL2RenderingContext) {
+  constructor(gl: WebGL2RenderingContext & UniversalRenderingContext) {
     super(gl, DistanceTexture.textureUnitId, {
-      minFilter: FilteringOptions.NEAREST,
-      maxFilter: FilteringOptions.NEAREST,
+      minFilter: FilteringOptions.LINEAR,
+      maxFilter: FilteringOptions.LINEAR,
     });
 
-    try {
-      enableExtension(gl, 'EXT_color_buffer_float');
-      this.floatEnabled = true;
+    const bufferFloatExtension = tryEnableExtension(gl, 'EXT_color_buffer_float');
+    const floatLinearExtension = tryEnableExtension(gl, 'OES_texture_float_linear');
+    this.floatLinearEnabled = !!bufferFloatExtension && !!floatLinearExtension;
 
-      enableExtension(gl, 'OES_texture_float_linear');
-      this.floatLinearEnabled = true;
-    } catch {
-      // it's okay
-    }
-
-    if (this.floatLinearEnabled) {
-      this.setTextureOptions({
-        minFilter: FilteringOptions.LINEAR,
-        maxFilter: FilteringOptions.LINEAR,
-      });
-    }
+    gl.insights.floatInterpolationEnabled = this.floatLinearEnabled;
   }
 
   public setSize(size: vec2) {
@@ -39,12 +28,12 @@ export class DistanceTexture extends Texture {
     this.gl.texImage2D(
       this.gl.TEXTURE_2D,
       0,
-      this.floatEnabled ? (this.gl as WebGL2RenderingContext).R16F : this.gl.RGBA,
+      this.floatLinearEnabled ? (this.gl as WebGL2RenderingContext).R16F : this.gl.RGBA,
       size.x,
       size.y,
       0,
-      this.floatEnabled ? (this.gl as WebGL2RenderingContext).RED : this.gl.RGBA,
-      this.floatEnabled
+      this.floatLinearEnabled ? (this.gl as WebGL2RenderingContext).RED : this.gl.RGBA,
+      this.floatLinearEnabled
         ? (this.gl as WebGL2RenderingContext).FLOAT
         : this.gl.UNSIGNED_BYTE,
       null