Files
openlayers/src/ol/renderer/webgl/Layer.js
Olivier Guyot 03e70bd10e Webgl points / handle using short instead of int for indices
This is controlled by the availability of the OES_element_index_uint
webgl extension.
2019-06-01 15:33:36 +02:00

239 lines
9.3 KiB
JavaScript

/**
* @module ol/renderer/webgl/Layer
*/
import LayerRenderer from '../Layer.js';
import WebGLHelper from '../../webgl/Helper.js';
/**
* @enum {string}
*/
export const WebGLWorkerMessageType = {
GENERATE_BUFFERS: 'GENERATE_BUFFERS'
};
/**
* @typedef {Object} WebGLWorkerGenerateBuffersMessage
* This message will trigger the generation of a vertex and an index buffer based on the given render instructions.
* When the buffers are generated, the worked will send a message of the same type to the main thread, with
* the generated buffers in it.
* Note that any addition properties present in the message *will* be sent back to the main thread.
* @property {WebGLWorkerMessageType} type Message type
* @property {ArrayBuffer} renderInstructions Render instructions raw binary buffer.
* @property {ArrayBuffer} [vertexBuffer] Vertices array raw binary buffer (sent by the worker).
* @property {ArrayBuffer} [indexBuffer] Indices array raw binary buffer (sent by the worker).
* @property {number} [customAttributesCount] Amount of custom attributes count in the render instructions.
* @property {boolean} [useShortIndices] If true, Uint16Array will be used instead of Uint32Array for index buffers.
*/
/**
* @typedef {Object} PostProcessesOptions
* @property {number} [scaleRatio] Scale ratio; if < 1, the post process will render to a texture smaller than
* the main canvas that will then be sampled up (useful for saving resource on blur steps).
* @property {string} [vertexShader] Vertex shader source
* @property {string} [fragmentShader] Fragment shader source
* @property {Object.<string,import("../../webgl/Helper").UniformValue>} [uniforms] Uniform definitions for the post process step
*/
/**
* @typedef {Object} Options
* @property {Object.<string,import("../../webgl/Helper").UniformValue>} [uniforms] Uniform definitions for the post process steps
* @property {Array<PostProcessesOptions>} [postProcesses] Post-processes definitions
*/
/**
* @classdesc
* Base WebGL renderer class.
* Holds all logic related to data manipulation & some common rendering logic
*/
class WebGLLayerRenderer extends LayerRenderer {
/**
* @param {import("../../layer/Layer.js").default} layer Layer.
* @param {Options=} [opt_options] Options.
*/
constructor(layer, opt_options) {
super(layer);
const options = opt_options || {};
this.helper_ = new WebGLHelper({
postProcesses: options.postProcesses,
uniforms: options.uniforms
});
}
/**
* @inheritDoc
*/
disposeInternal() {
super.disposeInternal();
}
/**
* Will return the last shader compilation errors. If no error happened, will return null;
* @return {string|null} Errors, or null if last compilation was successful
* @api
*/
getShaderCompileErrors() {
return this.helper_.getShaderCompileErrors();
}
}
/**
* @param {Float32Array} instructions Instructons array in which to write.
* @param {number} elementIndex Index from which render instructions will be written.
* @param {number} x Point center X coordinate
* @param {number} y Point center Y coordinate
* @param {number} u0 Left texture coordinate
* @param {number} v0 Bottom texture coordinate
* @param {number} u1 Right texture coordinate
* @param {number} v1 Top texture coordinate
* @param {number} size Radius of the point
* @param {number} opacity Opacity
* @param {boolean} rotateWithView If true, the point will stay aligned with the view
* @param {Array<number>} color Array holding red, green, blue, alpha values
* @return {number} Index from which the next element should be written
* @private
*/
export function writePointFeatureInstructions(instructions, elementIndex, x, y, u0, v0, u1, v1, size, opacity, rotateWithView, color) {
let i = elementIndex;
instructions[i++] = x;
instructions[i++] = y;
instructions[i++] = u0;
instructions[i++] = v0;
instructions[i++] = u1;
instructions[i++] = v1;
instructions[i++] = size;
instructions[i++] = opacity;
instructions[i++] = rotateWithView ? 1 : 0;
instructions[i++] = color[0];
instructions[i++] = color[1];
instructions[i++] = color[2];
instructions[i++] = color[3];
return i;
}
const tmpArray_ = [];
const bufferPositions_ = {vertexPosition: 0, indexPosition: 0};
export const POINT_INSTRUCTIONS_COUNT = 13;
export const POINT_VERTEX_STRIDE = 12;
function writePointVertex(buffer, pos, x, y, offsetX, offsetY, u, v, opacity, rotateWithView, red, green, blue, alpha) {
buffer[pos + 0] = x;
buffer[pos + 1] = y;
buffer[pos + 2] = offsetX;
buffer[pos + 3] = offsetY;
buffer[pos + 4] = u;
buffer[pos + 5] = v;
buffer[pos + 6] = opacity;
buffer[pos + 7] = rotateWithView;
buffer[pos + 8] = red;
buffer[pos + 9] = green;
buffer[pos + 10] = blue;
buffer[pos + 11] = alpha;
}
function writeCustomAttrs(buffer, pos, customAttrs) {
if (customAttrs.length) {
buffer.set(customAttrs, pos);
}
}
/**
* An object holding positions both in an index and a vertex buffer.
* @typedef {Object} BufferPositions
* @property {number} vertexPosition Position in the vertex buffer
* @property {number} indexPosition Position in the index buffer
*/
/**
* Pushes a quad (two triangles) based on a point geometry
* @param {Float32Array} instructions Array of render instructions for points.
* @param {number} elementIndex Index from which render instructions will be read.
* @param {Float32Array} vertexBuffer Buffer in the form of a typed array.
* @param {Uint16Array|Uint32Array} indexBuffer Buffer in the form of a typed array.
* @param {BufferPositions} [bufferPositions] Buffer write positions; if not specified, positions will be set at 0.
* @param {number} [count] Amount of render instructions that will be read. Default value is POINT_INSTRUCTIONS_COUNT
* but a higher value can be provided; all values beyond the default count will be put in the vertices buffer as
* is, thus allowing specifying custom attributes. Please note: this value should not vary inside the same buffer or
* rendering will break.
* @return {BufferPositions} New buffer positions where to write next
* @property {number} vertexPosition New position in the vertex buffer where future writes should start.
* @property {number} indexPosition New position in the index buffer where future writes should start.
* @private
*/
export function writePointFeatureToBuffers(instructions, elementIndex, vertexBuffer, indexBuffer, bufferPositions, count) {
const count_ = count > POINT_INSTRUCTIONS_COUNT ? count : POINT_INSTRUCTIONS_COUNT;
const x = instructions[elementIndex + 0];
const y = instructions[elementIndex + 1];
const u0 = instructions[elementIndex + 2];
const v0 = instructions[elementIndex + 3];
const u1 = instructions[elementIndex + 4];
const v1 = instructions[elementIndex + 5];
const size = instructions[elementIndex + 6];
const opacity = instructions[elementIndex + 7];
const rotateWithView = instructions[elementIndex + 8];
const red = instructions[elementIndex + 9];
const green = instructions[elementIndex + 10];
const blue = instructions[elementIndex + 11];
const alpha = instructions[elementIndex + 12];
// the default vertex buffer stride is 12, plus additional custom values if any
const baseStride = POINT_VERTEX_STRIDE;
const stride = baseStride + count_ - POINT_INSTRUCTIONS_COUNT;
// read custom numerical attributes on the feature
const customAttrs = tmpArray_;
customAttrs.length = count_ - POINT_INSTRUCTIONS_COUNT;
for (let i = 0; i < customAttrs.length; i++) {
customAttrs[i] = instructions[elementIndex + POINT_INSTRUCTIONS_COUNT + i];
}
let vPos = bufferPositions ? bufferPositions.vertexPosition : 0;
let iPos = bufferPositions ? bufferPositions.indexPosition : 0;
const baseIndex = vPos / stride;
// push vertices for each of the four quad corners (first standard then custom attributes)
writePointVertex(vertexBuffer, vPos, x, y, -size / 2, -size / 2, u0, v0, opacity, rotateWithView, red, green, blue, alpha);
writeCustomAttrs(vertexBuffer, vPos + baseStride, customAttrs);
vPos += stride;
writePointVertex(vertexBuffer, vPos, x, y, +size / 2, -size / 2, u1, v0, opacity, rotateWithView, red, green, blue, alpha);
writeCustomAttrs(vertexBuffer, vPos + baseStride, customAttrs);
vPos += stride;
writePointVertex(vertexBuffer, vPos, x, y, +size / 2, +size / 2, u1, v1, opacity, rotateWithView, red, green, blue, alpha);
writeCustomAttrs(vertexBuffer, vPos + baseStride, customAttrs);
vPos += stride;
writePointVertex(vertexBuffer, vPos, x, y, -size / 2, +size / 2, u0, v1, opacity, rotateWithView, red, green, blue, alpha);
writeCustomAttrs(vertexBuffer, vPos + baseStride, customAttrs);
vPos += stride;
indexBuffer[iPos++] = baseIndex; indexBuffer[iPos++] = baseIndex + 1; indexBuffer[iPos++] = baseIndex + 3;
indexBuffer[iPos++] = baseIndex + 1; indexBuffer[iPos++] = baseIndex + 2; indexBuffer[iPos++] = baseIndex + 3;
bufferPositions_.vertexPosition = vPos;
bufferPositions_.indexPosition = iPos;
return bufferPositions_;
}
/**
* Returns a texture of 1x1 pixel, white
* @private
* @return {ImageData} Image data.
*/
export function getBlankTexture() {
const canvas = document.createElement('canvas');
const image = canvas.getContext('2d').createImageData(1, 1);
image.data[0] = image.data[1] = image.data[2] = image.data[3] = 255;
return image;
}
export default WebGLLayerRenderer;