@lightningtv/renderer/src/core/renderers/webgl/WebGlCtxRenderTexture.ts

Lightning 3 Renderer

/*
 * If not stated otherwise in this file or this component's LICENSE file the
 * following copyright and licenses apply:
 *
 * Copyright 2024 Comcast Cable Communications Management, LLC.
 *
 * Licensed under the Apache License, Version 2.0 (the License);
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

import type { Dimensions } from '../../../common/CommonTypes.js';
import { assertTruthy } from '../../../utils.js';
import type { TextureMemoryManager } from '../../TextureMemoryManager.js';
import type { WebGlContextWrapper } from '../../lib/WebGlContextWrapper.js';
import type { RenderTexture } from '../../textures/RenderTexture.js';
import { WebGlCtxTexture } from './WebGlCtxTexture.js';

export class WebGlCtxRenderTexture extends WebGlCtxTexture {
  declare textureSource: RenderTexture;

  public framebuffer: WebGLFramebuffer | null = null;

  constructor(
    glw: WebGlContextWrapper,
    memManager: TextureMemoryManager,
    textureSource: RenderTexture,
  ) {
    super(glw, memManager, textureSource);
  }

  override async onLoadRequest(): Promise<Dimensions> {
    const { glw } = this;
    const nativeTexture = (this._nativeCtxTexture =
      this.createNativeCtxTexture());
    const { width, height } = this.textureSource;

    // Create Framebuffer object
    this.framebuffer = glw.createFramebuffer();

    // Set the dimensions of the render texture
    glw.texImage2D(
      0,
      glw.RGBA,
      width,
      height,
      0,
      glw.RGBA,
      glw.UNSIGNED_BYTE,
      null,
    );

    // Update the texture memory manager
    this.setTextureMemUse(width * height * 4);

    // Bind the framebuffer
    glw.bindFramebuffer(this.framebuffer);

    // Attach the texture to the framebuffer
    glw.framebufferTexture2D(glw.COLOR_ATTACHMENT0, nativeTexture, 0);

    // Unbind the framebuffer
    glw.bindFramebuffer(null);

    return {
      width,
      height,
    };
  }

  override free(): void {
    super.free();

    // Delete the framebuffer
    this.glw.deleteFramebuffer(this.framebuffer);
    this.framebuffer = null;
  }
}