Initial commit

node_modules/maplibre-gl/src/gl/index_buffer.ts

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+
+import type {StructArray} from '../util/struct_array';
+import type {TriangleIndexArray, LineIndexArray, LineStripIndexArray} from '../data/index_array_type';
+import type {Context} from '../gl/context';
+
+/**
+ * @internal
+ * an index buffer class
+ */
+export class IndexBuffer {
+    context: Context;
+    buffer: WebGLBuffer;
+    dynamicDraw: boolean;
+
+    constructor(context: Context, array: TriangleIndexArray | LineIndexArray | LineStripIndexArray, dynamicDraw?: boolean) {
+        this.context = context;
+        const gl = context.gl;
+        this.buffer = gl.createBuffer();
+        this.dynamicDraw = Boolean(dynamicDraw);
+
+        // The bound index buffer is part of vertex array object state. We don't want to
+        // modify whatever VAO happens to be currently bound, so make sure the default
+        // vertex array provided by the context is bound instead.
+        this.context.unbindVAO();
+
+        context.bindElementBuffer.set(this.buffer);
+        gl.bufferData(gl.ELEMENT_ARRAY_BUFFER, array.arrayBuffer, this.dynamicDraw ? gl.DYNAMIC_DRAW : gl.STATIC_DRAW);
+
+        if (!this.dynamicDraw) {
+            array.freeBufferAfterUpload();
+        }
+    }
+
+    bind() {
+        this.context.bindElementBuffer.set(this.buffer);
+    }
+
+    updateData(array: StructArray) {
+        const gl = this.context.gl;
+        if (!this.dynamicDraw) throw new Error('Attempted to update data while not in dynamic mode.');
+        // The right VAO will get this buffer re-bound later in VertexArrayObject.bind
+        // See https://github.com/mapbox/mapbox-gl-js/issues/5620
+        this.context.unbindVAO();
+        this.bind();
+        gl.bufferSubData(gl.ELEMENT_ARRAY_BUFFER, 0, array.arrayBuffer);
+    }
+
+    destroy() {
+        const gl = this.context.gl;
+        if (this.buffer) {
+            gl.deleteBuffer(this.buffer);
+            delete this.buffer;
+        }
+    }
+}