Fix missing activeTexture patch

Author: chubei-urus

src/augment-api.js

@@ -128,6 +128,7 @@ export function augmentAPI(ctx, nameOfClass, options = {}) {
       sharedState.webglObjectToMemory.clear();
       sharedState.webglObjectToMemory.set(sharedState.defaultVertexArray, {});
       sharedState.currentVertexArray = sharedState.defaultVertexArray;
+      sharedState.activeTextureUnit = 0x84C0; // TEXTURE0
       [sharedState.resources, sharedState.memory].forEach(function(obj) {
         for (const prop in obj) {
           obj[prop] = 0;
@@ -179,6 +180,10 @@ export function augmentAPI(ctx, nameOfClass, options = {}) {
     return sharedState;
   }
 
+  function getTextureBindingKey(target) {
+    return `${sharedState.activeTextureUnit}_${target}`;
+  }
+
   const sharedState = options.sharedState || createSharedState(ctx);
   options.sharedState = sharedState;
 
@@ -256,6 +261,7 @@ export function augmentAPI(ctx, nameOfClass, options = {}) {
   }
 
   const ELEMENT_ARRAY_BUFFER           = 0x8893;
+  const TEXTURE0                       = 0x84C0;
 
   const UNSIGNED_BYTE                  = 0x1401;
   const TEXTURE_CUBE_MAP               = 0x8513;
@@ -285,9 +291,10 @@ export function augmentAPI(ctx, nameOfClass, options = {}) {
 
   function getTextureInfo(target) {
     target = isCubemapFace(target) ? TEXTURE_CUBE_MAP : target;
-    const obj = bindings.get(target);
+    const bindingKey = getTextureBindingKey(target);
+    const obj = bindings.get(bindingKey);
     if (!obj) {
-      throw new Error(`no texture bound to ${target}`);
+      throw new Error(`no texture bound to ${target} on unit ${sharedState.activeTextureUnit - TEXTURE0}`);
     }
     const info = webglObjectToMemory.get(obj);
     if (!info) {
@@ -439,12 +446,21 @@ export function augmentAPI(ctx, nameOfClass, options = {}) {
       bindings.set(target, obj);
     },
 
+    activeTexture(gl, funcName, args) {
+      if (sharedState.isContextLost) {
+        return;
+      }
+      const [unit] = args;
+      sharedState.activeTextureUnit = unit;
+    },
+
     bindTexture(gl, funcName, args) {
       if (sharedState.isContextLost) {
        return;
       }
       const [target, obj] = args;
-      bindings.set(target, obj);
+      const bindingKey = getTextureBindingKey(target);
+      bindings.set(bindingKey, obj);
     },
 
     // void gl.copyTexImage2D(target, level, internalformat, x, y, width, height, border);