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Use appropriate unpackAlignment for data textures

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This commit is contained in:
mike-000
2021-11-16 16:51:47 +00:00
committed by Tim Schaub
parent a715b1f5c6
commit dc7303967c
1 changed files with 59 additions and 20 deletions
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79
src/ol/webgl/TileTexture.js
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@@ -36,8 +36,16 @@ function uploadImageTexture(gl, texture, image) {
* @param {import("../DataTile.js").Data} data The pixel data.
* @param {import("../size.js").Size} size The pixel size.
* @param {number} bandCount The band count.
* @param {number} unpackAlignment The unpack alignment.
*/
function uploadDataTexture(helper, texture, data, size, bandCount) {
function uploadDataTexture(
helper,
texture,
data,
size,
bandCount,
unpackAlignment
) {
const gl = helper.getGL();
bindAndConfigure(gl, texture);
@@ -73,6 +81,7 @@ function uploadDataTexture(helper, texture, data, size, bandCount) {
textureType = gl.UNSIGNED_BYTE;
}
gl.pixelStorei(gl.UNPACK_ALIGNMENT, unpackAlignment);
gl.texImage2D(
gl.TEXTURE_2D,
0,
@@ -84,6 +93,7 @@ function uploadDataTexture(helper, texture, data, size, bandCount) {
textureType,
data
);
gl.pixelStorei(gl.UNPACK_ALIGNMENT, 4);
}
/**
@@ -168,21 +178,37 @@ 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 byteWidth = data.byteLength / this.size[1];
this.bandCount = Math.floor(byteWidth / bytesPerElement / this.size[0]);
const textureCount = Math.ceil(this.bandCount / 4);
let unpackAlignment;
if (byteWidth % 8 === 0) {
unpackAlignment = 8;
} else if (byteWidth % 4 === 0) {
unpackAlignment = 4;
} else if (byteWidth % 2 === 0) {
unpackAlignment = 2;
} else {
unpackAlignment = 1;
}
if (textureCount === 1) {
const texture = gl.createTexture();
this.textures.push(texture);
uploadDataTexture(helper, texture, data, this.size, this.bandCount);
uploadDataTexture(
helper,
texture,
data,
this.size,
this.bandCount,
unpackAlignment
);
return;
}
const DataType = isFloat ? Float32Array : Uint8Array;
const textureDataArrays = new Array(textureCount);
for (let textureIndex = 0; textureIndex < textureCount; ++textureIndex) {
const texture = gl.createTexture();
@@ -193,17 +219,23 @@ 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 valueCount = this.size[0] * this.bandCount;
for (let rowIndex = 0; rowIndex < this.size[1]; ++rowIndex) {
for (let colIndex = 0; colIndex < valueCount; ++colIndex) {
const bandIndex = colIndex % 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[rowOffset + colIndex];
++dataIndex;
}
rowOffset += byteWidth / bytesPerElement;
}
for (let textureIndex = 0; textureIndex < textureCount; ++textureIndex) {
@@ -211,7 +243,14 @@ class TileTexture extends EventTarget {
textureIndex < textureCount - 1 ? 4 : this.bandCount % 4;
const texture = this.textures[textureIndex];
const data = textureDataArrays[textureIndex];
uploadDataTexture(helper, texture, data, this.size, bandCount);
uploadDataTexture(
helper,
texture,
data,
this.size,
bandCount,
bytesPerElement
);
}
}