Implementation of baseVertex support

src/extras/mini-stats/render2d.js

@@ -91,6 +91,7 @@ class Render2d {
             type: PRIMITIVE_TRIANGLES,
             indexed: true,
             base: 0,
+            baseVertex: 0,
             count: 0
         };
         this.quads = 0;

src/platform/graphics/transform-feedback.js

@@ -158,6 +158,7 @@ class TransformFeedback {
         device.draw({
             type: PRIMITIVE_POINTS,
             base: 0,
+            baseVertex: 0,
             count: this._inputBuffer.numVertices,
             indexed: false
         });

src/platform/graphics/webgpu/webgpu-clear-renderer.js

@@ -16,6 +16,7 @@ import { DepthState } from '../depth-state.js';
 const primitive = {
     type: PRIMITIVE_TRISTRIP,
     base: 0,
+    baseVertex: 0,
     count: 4,
     indexed: false
 };

src/platform/graphics/webgpu/webgpu-graphics-device.js

@@ -536,6 +536,43 @@ class WebgpuGraphicsDevice extends GraphicsDevice {
         _uniqueLocations.clear();
     }
 
+    /**
+     * Submits a graphical primitive to the hardware for immediate rendering.
+     *
+     * @param {object} primitive - Primitive object describing how to submit current vertex/index
+     * buffers.
+     * @param {number} primitive.type - The type of primitive to render. Can be:
+     *
+     * - {@link PRIMITIVE_POINTS}
+     * - {@link PRIMITIVE_LINES}
+     * - {@link PRIMITIVE_LINELOOP}
+     * - {@link PRIMITIVE_LINESTRIP}
+     * - {@link PRIMITIVE_TRIANGLES}
+     * - {@link PRIMITIVE_TRISTRIP}
+     * - {@link PRIMITIVE_TRIFAN}
+     *
+     * @param {number} primitive.base - The offset of the first index or vertex to dispatch in the
+     * draw call.
+     * @param {number} primitive.baseVertex - The number added to each index value before indexing into
+     * the vertex buffers.
+     * @param {number} primitive.count - The number of indices or vertices to dispatch in the draw
+     * call.
+     * @param {boolean} [primitive.indexed] - True to interpret the primitive as indexed, thereby
+     * using the currently set index buffer and false otherwise.
+     * @param {number} [numInstances] - The number of instances to render when using instancing.
+     * Defaults to 1.
+     * @param {boolean} [keepBuffers] - Optionally keep the current set of vertex / index buffers /
+     * VAO. This is used when rendering of multiple views, for example under WebXR.
+     * @example
+     * // Render a single, unindexed triangle
+     * device.draw({
+     *     type: pc.PRIMITIVE_TRIANGLES,
+     *     base: 0,
+     *     baseVertex: 0,
+     *     count: 3,
+     *     indexed: false
+     * });
+     */
     draw(primitive, numInstances = 1, keepBuffers) {
 
         if (this.shader.ready && !this.shader.failed) {
@@ -574,7 +611,7 @@ class WebgpuGraphicsDevice extends GraphicsDevice {
             if (ib) {
                 this.indexBuffer = null;
                 passEncoder.setIndexBuffer(ib.impl.buffer, ib.impl.format);
-                passEncoder.drawIndexed(primitive.count, numInstances, primitive.base, 0, 0);
+                passEncoder.drawIndexed(primitive.count, numInstances, primitive.base, primitive.baseVertex || 0, 0);
             } else {
                 passEncoder.draw(primitive.count, numInstances, primitive.base, 0);
             }

src/scene/batching/batch-manager.js

@@ -659,7 +659,7 @@ class BatchManager {
             batch = new Batch(meshInstances, dynamic, batchGroupId);
             this._batchList.push(batch);
 
-            let indexBase, numIndices, indexData;
+            let indexBase, indexBaseVertex, numIndices, indexData;
             let verticesOffset = 0;
             let indexOffset = 0;
             let transform;
@@ -738,6 +738,7 @@ class BatchManager {
                 // index buffer
                 if (mesh.primitive[0].indexed) {
                     indexBase = mesh.primitive[0].base;
+                    indexBaseVertex = mesh.primitive[0].baseVertex || 0;
                     numIndices = mesh.primitive[0].count;
 
                     // source index buffer data mapped to its format
@@ -746,6 +747,8 @@ class BatchManager {
 
                 } else { // non-indexed
 
+                    indexBaseVertex = 0;
+
                     const primitiveType = mesh.primitive[0].type;
                     if (primitiveType === PRIMITIVE_TRIFAN || primitiveType === PRIMITIVE_TRISTRIP) {
                         if (mesh.primitive[0].count === 4) {
@@ -760,7 +763,7 @@ class BatchManager {
                 }
 
                 for (let j = 0; j < numIndices; j++) {
-                    indices[j + indexOffset] = indexData[indexBase + j] + verticesOffset;
+                    indices[j + indexOffset] = indexData[indexBase + j] + indexBaseVertex + verticesOffset;
                 }
 
                 indexOffset += numIndices;

src/scene/graphics/quad-render.js

@@ -14,6 +14,7 @@ import { processShader } from '../shader-lib/utils.js';
 const _quadPrimitive = {
     type: PRIMITIVE_TRISTRIP,
     base: 0,
+    baseVertex: 0,
     count: 4,
     indexed: false
 };

src/scene/mesh.js

@@ -202,14 +202,16 @@ class Mesh extends RefCountedObject {
      *
      * - `base` is the offset of the first index or vertex to dispatch in the draw call.
      * - `count` is the number of indices or vertices to dispatch in the draw call.
+     * - `baseVertex` is the number added to each index value before indexing into the vertex buffers. (available only for WebGPU and Batching)
      * - `indexed` specifies whether to interpret the primitive as indexed, thereby using the
      * currently set index buffer.
      *
-     * @type {{type: number, base: number, count: number, indexed?: boolean}[]}
+     * @type {{type: number, base: number, count: number, baseVertex: number, indexed?: boolean}[]}
      */
     primitive = [{
         type: 0,
         base: 0,
+        baseVertex: 0,
         count: 0
     }];
 
@@ -1044,6 +1046,7 @@ class Mesh extends RefCountedObject {
             this.primitive[RENDERSTYLE_POINTS] = {
                 type: PRIMITIVE_POINTS,
                 base: 0,
+                baseVertex: 0,
                 count: this.vertexBuffer ? this.vertexBuffer.numVertices : 0,
                 indexed: false
             };