From 0ed53eb50107395f795e91206fe75de54ca5925f Mon Sep 17 00:00:00 2001
From: sakitam-fdd <smilefdd@gmail.com>
Date: Thu, 2 Jun 2022 23:12:30 +0800
Subject: [PATCH] feat(core): RenderBuffer

---
 src/core/RenderBuffer.ts | 64 ++++++++++++++++++++++++++++++++++++++++
 1 file changed, 64 insertions(+)
 create mode 100644 src/core/RenderBuffer.ts

diff --git a/src/core/RenderBuffer.ts b/src/core/RenderBuffer.ts
new file mode 100644
index 00000000..cdb3fbea
--- /dev/null
+++ b/src/core/RenderBuffer.ts
@@ -0,0 +1,64 @@
+import Resource from './Resource';
+import Renderer from './Renderer';
+
+export interface RenderBufferOptions {
+  width: number;
+  height: number;
+
+  format: GLenum;
+}
+
+export default class RenderBuffer extends Resource<RenderBufferOptions> {
+  public width: number;
+
+  public height: number;
+
+  #internalFormat: GLenum;
+
+  constructor (renderer: Renderer, options: RenderBufferOptions = {} as RenderBufferOptions) {
+    super(renderer, {
+      ...options,
+      format: options.format || renderer.gl.DEPTH_COMPONENT16,
+    });
+
+    this.#internalFormat = this.options.format as GLenum;
+
+    this.width = this.options.width as number;
+    this.height = this.options.height as number;
+
+    console.assert(
+      this.width > 0 && this.height > 0,
+      'Renderbuffer object requires valid width and height greater than zero'
+    );
+    this.bind();
+    renderer.gl.renderbufferStorage(renderer.gl.RENDERBUFFER, this.#internalFormat, this.width, this.height);
+  }
+
+  resize (width, height) {
+    if (width === this.width && height === this.height) return;
+    this.bind();
+    this.gl.renderbufferStorage(this.gl.RENDERBUFFER, this.#internalFormat, width, height);
+    this.unbind();
+  }
+
+  bind () {
+    this.gl.bindRenderbuffer(this.gl.RENDERBUFFER, this.handle);
+  }
+
+  unbind () {
+    this.gl.bindRenderbuffer(this.gl.RENDERBUFFER, null);
+  }
+
+  destroy () {
+    this.unbind();
+    this.deleteHandle();
+  }
+
+  createHandle () {
+    return this.gl.createRenderbuffer();
+  }
+
+  deleteHandle () {
+    this.handle && this.gl.deleteRenderbuffer(this.handle);
+  }
+}