Merge pull request #13013 from mike-000/unpack-alignment

Use appropriate UNPACK_ALIGNMENT for data textures

src/ol/webgl/TileTexture.js

@@ -41,6 +41,16 @@ function uploadDataTexture(helper, texture, data, size, bandCount) {
   const gl = helper.getGL();
   bindAndConfigure(gl, texture);
 
+  const bytesPerRow = data.byteLength / size[1];
+  let unpackAlignment = 1;
+  if (bytesPerRow % 8 === 0) {
+    unpackAlignment = 8;
+  } else if (bytesPerRow % 4 === 0) {
+    unpackAlignment = 4;
+  } else if (bytesPerRow % 2 === 0) {
+    unpackAlignment = 2;
+  }
+
   let format;
   switch (bandCount) {
     case 1: {
@@ -73,6 +83,8 @@ function uploadDataTexture(helper, texture, data, size, bandCount) {
     textureType = gl.UNSIGNED_BYTE;
   }
 
+  const oldUnpackAlignment = gl.getParameter(gl.UNPACK_ALIGNMENT);
+  gl.pixelStorei(gl.UNPACK_ALIGNMENT, unpackAlignment);
   gl.texImage2D(
     gl.TEXTURE_2D,
     0,
@@ -84,6 +96,7 @@ function uploadDataTexture(helper, texture, data, size, bandCount) {
     textureType,
     data
   );
+  gl.pixelStorei(gl.UNPACK_ALIGNMENT, oldUnpackAlignment);
 }
 
 /**
@@ -168,10 +181,11 @@ class TileTexture extends EventTarget {
     const data = tile.getData();
     const isFloat = data instanceof Float32Array;
     const pixelCount = this.size[0] * this.size[1];
-    // Float arrays feature four bytes per element,
-    //  BYTES_PER_ELEMENT throws a TypeScript exception but would handle
-    //  this better for more varied typed arrays.
-    this.bandCount = data.byteLength / (isFloat ? 4 : 1) / pixelCount;
+    const DataType = isFloat ? Float32Array : Uint8Array;
+    const bytesPerElement = DataType.BYTES_PER_ELEMENT;
+    const bytesPerRow = data.byteLength / this.size[1];
+
+    this.bandCount = Math.floor(bytesPerRow / bytesPerElement / this.size[0]);
     const textureCount = Math.ceil(this.bandCount / 4);
 
     if (textureCount === 1) {
@@ -181,8 +195,6 @@ class TileTexture extends EventTarget {
       return;
     }
 
-    const DataType = isFloat ? Float32Array : Uint8Array;
-
     const textureDataArrays = new Array(textureCount);
     for (let textureIndex = 0; textureIndex < textureCount; ++textureIndex) {
       const texture = gl.createTexture();
@@ -193,25 +205,31 @@ class TileTexture extends EventTarget {
       textureDataArrays[textureIndex] = new DataType(pixelCount * bandCount);
     }
 
-    const valueCount = pixelCount * this.bandCount;
-    for (let dataIndex = 0; dataIndex < valueCount; ++dataIndex) {
-      const bandIndex = dataIndex % this.bandCount;
-      const textureBandIndex = bandIndex % 4;
-      const textureIndex = Math.floor(bandIndex / 4);
-      const bandCount =
-        textureIndex < textureCount - 1 ? 4 : this.bandCount % 4;
-      const pixelIndex = Math.floor(dataIndex / this.bandCount);
-      textureDataArrays[textureIndex][
-        pixelIndex * bandCount + textureBandIndex
-      ] = data[dataIndex];
+    let dataIndex = 0;
+    let rowOffset = 0;
+    const colCount = this.size[0] * this.bandCount;
+    for (let rowIndex = 0; rowIndex < this.size[1]; ++rowIndex) {
+      for (let colIndex = 0; colIndex < colCount; ++colIndex) {
+        const dataValue = data[rowOffset + colIndex];
+
+        const pixelIndex = Math.floor(dataIndex / this.bandCount);
+        const bandIndex = colIndex % this.bandCount;
+        const textureIndex = Math.floor(bandIndex / 4);
+        const textureData = textureDataArrays[textureIndex];
+        const bandCount = textureData.length / pixelCount;
+        const textureBandIndex = bandIndex % 4;
+        textureData[pixelIndex * bandCount + textureBandIndex] = dataValue;
+
+        ++dataIndex;
+      }
+      rowOffset += bytesPerRow / bytesPerElement;
     }
 
     for (let textureIndex = 0; textureIndex < textureCount; ++textureIndex) {
-      const bandCount =
-        textureIndex < textureCount - 1 ? 4 : this.bandCount % 4;
       const texture = this.textures[textureIndex];
-      const data = textureDataArrays[textureIndex];
-      uploadDataTexture(helper, texture, data, this.size, bandCount);
+      const textureData = textureDataArrays[textureIndex];
+      const bandCount = textureData.length / pixelCount;
+      uploadDataTexture(helper, texture, textureData, this.size, bandCount);
     }
   }
 

test/rendering/cases/webgl-data-tile-3-band/main.js

@@ -0,0 +1,49 @@
+import DataTile from '../../../../src/ol/source/DataTile.js';
+import Map from '../../../../src/ol/Map.js';
+import TileLayer from '../../../../src/ol/layer/WebGLTile.js';
+import View from '../../../../src/ol/View.js';
+
+const size = [81, 99];
+
+const canvas = document.createElement('canvas');
+canvas.width = size[0];
+canvas.height = size[1];
+
+const context = canvas.getContext('2d');
+context.strokeStyle = 'white';
+context.textAlign = 'center';
+const lineHeight = 16;
+context.font = `${lineHeight}px sans-serif`;
+
+new Map({
+  target: 'map',
+  layers: [
+    new TileLayer({
+      source: new DataTile({
+        loader: function (z, x, y) {
+          const halfWidth = size[0] / 2;
+          const halfHeight = size[1] / 2;
+          context.fillStyle = '#00AAFF';
+          context.fillRect(0, 0, size[0], size[1]);
+          context.fillStyle = 'white';
+          context.fillText(`z: ${z}`, halfWidth, halfHeight - lineHeight);
+          context.fillText(`x: ${x}`, halfWidth, halfHeight);
+          context.fillText(`y: ${y}`, halfWidth, halfHeight + lineHeight);
+          context.strokeRect(0, 0, size[0], size[1]);
+          const data = context.getImageData(0, 0, size[0], size[1]).data;
+
+          const bandCount = 3;
+          const result = data.filter((_, index) => index % 4 < bandCount);
+          return Promise.resolve(result);
+        },
+        tileSize: size,
+      }),
+    }),
+  ],
+  view: new View({
+    center: [0, 0],
+    zoom: 4,
+  }),
+});
+
+render({tolerance: 0.03});

test/rendering/cases/webgl-data-tile-loosely-packed/main.js

@@ -0,0 +1,67 @@
+import DataTile from '../../../../src/ol/source/DataTile.js';
+import Map from '../../../../src/ol/Map.js';
+import TileLayer from '../../../../src/ol/layer/WebGLTile.js';
+import View from '../../../../src/ol/View.js';
+
+const size = [81, 99];
+
+const canvas = document.createElement('canvas');
+canvas.width = size[0];
+canvas.height = size[1];
+
+const context = canvas.getContext('2d');
+context.strokeStyle = 'white';
+context.textAlign = 'center';
+const lineHeight = 16;
+context.font = `${lineHeight}px sans-serif`;
+
+new Map({
+  target: 'map',
+  layers: [
+    new TileLayer({
+      source: new DataTile({
+        tileSize: size,
+        loader: function (z, x, y) {
+          const halfW = size[0] / 2;
+          const halfH = size[1] / 2;
+          context.fillStyle = '#00AAFF';
+          context.fillRect(0, 0, size[0], size[1]);
+          context.fillStyle = 'white';
+          context.fillText(`z: ${z}`, halfW, halfH - lineHeight);
+          context.fillText(`x: ${x}`, halfW, halfH);
+          context.fillText(`y: ${y}`, halfW, halfH + lineHeight);
+          context.strokeRect(0, 0, size[0], size[1]);
+
+          const input = context.getImageData(0, 0, size[0], size[1]).data;
+          const bandCount = input.length / (size[0] * size[1]);
+          const inputColCount = bandCount * size[0];
+
+          const packAlignment = 8;
+          const outputColCount =
+            Math.ceil((bandCount * size[0]) / packAlignment) * packAlignment;
+          const output = new Uint8Array(outputColCount * size[1]);
+
+          for (let row = 0; row < size[1]; ++row) {
+            let inputOffset = row * inputColCount;
+            let outputOffset = row * outputColCount;
+            for (let col = 0; col < inputColCount; col += bandCount) {
+              for (let band = 0; band < bandCount; ++band) {
+                output[outputOffset] = input[inputOffset];
+                inputOffset += 1;
+                outputOffset += 1;
+              }
+            }
+          }
+
+          return Promise.resolve(output);
+        },
+      }),
+    }),
+  ],
+  view: new View({
+    center: [0, 0],
+    zoom: 4,
+  }),
+});
+
+render({tolerance: 0.03});