Files
openlayers/src/ol/renderer/webgl/PointsLayer.js
Olivier Guyot 1257ade199 Webgl renderer / rename function to avoid confusion
`getBlankTexture` was too close to `WebGLHelper#createTexture`
2019-06-28 09:12:20 +02:00

524 lines
18 KiB
JavaScript

/**
* @module ol/renderer/webgl/PointsLayer
*/
import WebGLArrayBuffer from '../../webgl/Buffer.js';
import {DYNAMIC_DRAW, ARRAY_BUFFER, ELEMENT_ARRAY_BUFFER, FLOAT} from '../../webgl.js';
import {DefaultAttrib, DefaultUniform} from '../../webgl/Helper.js';
import GeometryType from '../../geom/GeometryType.js';
import WebGLLayerRenderer, {
colorEncodeId,
getBlankImageData,
POINT_INSTRUCTIONS_COUNT, POINT_VERTEX_STRIDE, WebGLWorkerMessageType,
writePointFeatureInstructions
} from './Layer.js';
import ViewHint from '../../ViewHint.js';
import {createEmpty, equals} from '../../extent.js';
import {
create as createTransform,
makeInverse as makeInverseTransform,
multiply as multiplyTransform,
apply as applyTransform
} from '../../transform.js';
import {create as createWebGLWorker} from '../../worker/webgl.js';
import {getUid} from '../../util.js';
const VERTEX_SHADER = `
precision mediump float;
attribute vec2 a_position;
attribute vec2 a_texCoord;
attribute float a_rotateWithView;
attribute vec2 a_offsets;
attribute float a_opacity;
attribute vec4 a_color;
uniform mat4 u_projectionMatrix;
uniform mat4 u_offsetScaleMatrix;
uniform mat4 u_offsetRotateMatrix;
varying vec2 v_texCoord;
varying float v_opacity;
varying vec4 v_color;
void main(void) {
mat4 offsetMatrix = u_offsetScaleMatrix;
if (a_rotateWithView == 1.0) {
offsetMatrix = u_offsetScaleMatrix * u_offsetRotateMatrix;
}
vec4 offsets = offsetMatrix * vec4(a_offsets, 0.0, 0.0);
gl_Position = u_projectionMatrix * vec4(a_position, 0.0, 1.0) + offsets;
v_texCoord = a_texCoord;
v_opacity = a_opacity;
v_color = a_color;
}`;
const FRAGMENT_SHADER = `
precision mediump float;
uniform sampler2D u_texture;
varying vec2 v_texCoord;
varying float v_opacity;
varying vec4 v_color;
void main(void) {
if (v_opacity == 0.0) {
discard;
}
vec4 textureColor = texture2D(u_texture, v_texCoord);
gl_FragColor = v_color * textureColor;
gl_FragColor.a *= v_opacity;
gl_FragColor.rgb *= gl_FragColor.a;
}`;
const HIT_FRAGMENT_SHADER = `
precision mediump float;
uniform sampler2D u_texture;
varying vec2 v_texCoord;
varying float v_opacity;
varying vec4 v_color;
void main(void) {
if (v_opacity == 0.0) {
discard;
}
vec4 textureColor = texture2D(u_texture, v_texCoord);
if (textureColor.a < 0.1) {
discard;
}
gl_FragColor = v_color;
}`;
/**
* @typedef {Object} Options
* @property {function(import("../../Feature").default):number} [sizeCallback] Will be called on every feature in the
* source to compute the size of the quad on screen (in pixels). This is only done on source change.
* @property {function(import("../../Feature").default, number):number} [coordCallback] Will be called on every feature in the
* source to compute the coordinate of the quad center on screen (in pixels). This is only done on source change.
* The second argument is 0 for `x` component and 1 for `y`.
* @property {function(import("../../Feature").default, number):number} [texCoordCallback] Will be called on every feature in the
* source to compute the texture coordinates of each corner of the quad (without effect if no `texture` option defined). This is only done on source change.
* The second argument is 0 for `u0` component, 1 for `v0`, 2 for `u1`, and 3 for `v1`.
* @property {function(import("../../Feature").default, Array<number>=):Array<number>} [colorCallback] Will be called on every feature in the
* source to compute the color for use in the fragment shader (available as the `v_color` varying). This is only done on source change.
* The return value should be between an array of R, G, B, A values between 0 and 1. To reduce unnecessary
* allocation, the function is called with a reusable array that can serve as the return value after updating
* the R, G, B, and A values.
* @property {function(import("../../Feature").default):number} [opacityCallback] Will be called on every feature in the
* source to compute the opacity of the quad on screen (from 0 to 1). This is only done on source change.
* Note: this is multiplied with the color of the point which can also have an alpha value < 1.
* @property {function(import("../../Feature").default):boolean} [rotateWithViewCallback] Will be called on every feature in the
* source to compute whether the quad on screen must stay upwards (`false`) or follow the view rotation (`true`).
* This is only done on source change.
* @property {HTMLCanvasElement|HTMLImageElement|ImageData} [texture] Texture to use on points. `texCoordCallback` and `sizeCallback`
* must be defined for this to have any effect.
* @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 steps
* Please note that `u_texture` is reserved for the main texture slot.
* @property {Array<import("./Layer").PostProcessesOptions>} [postProcesses] Post-processes definitions
*/
/**
* @classdesc
* WebGL vector renderer optimized for points.
* All features will be rendered as quads (two triangles forming a square). New data will be flushed to the GPU
* every time the vector source changes.
*
* Use shaders to customize the final output. The following attributes are available:
* * `vec2 a_position`
* * `vec2 a_texCoord`
* * `vec2 a_offsets`
* * `float a_rotateWithView`
* * `float a_opacity`
* * `float a_color`
*
* The following uniform is used for the main texture: `u_texture`.
*
* Please note that the main shader output should have premultiplied alpha, otherwise visual anomalies may occur.
*
* Points are rendered as quads with the following structure:
*
* ```
* (u0, v1) (u1, v1)
* [3]----------[2]
* |` |
* | ` |
* | ` |
* | ` |
* | ` |
* | ` |
* [0]----------[1]
* (u0, v0) (u1, v0)
* ```
*
* This uses {@link module:ol/webgl/Helper~WebGLHelper} internally.
*
* Default shaders are shown hereafter:
*
* * Vertex shader:
* ```
* precision mediump float;
*
* attribute vec2 a_position;
* attribute vec2 a_texCoord;
* attribute float a_rotateWithView;
* attribute vec2 a_offsets;
* attribute float a_opacity;
* attribute vec4 a_color;
*
* uniform mat4 u_projectionMatrix;
* uniform mat4 u_offsetScaleMatrix;
* uniform mat4 u_offsetRotateMatrix;
*
* varying vec2 v_texCoord;
* varying float v_opacity;
* varying vec4 v_color;
*
* void main(void) {
* mat4 offsetMatrix = u_offsetScaleMatrix;
* if (a_rotateWithView == 1.0) {
* offsetMatrix = u_offsetScaleMatrix * u_offsetRotateMatrix;
* }
* vec4 offsets = offsetMatrix * vec4(a_offsets, 0.0, 0.0);
* gl_Position = u_projectionMatrix * vec4(a_position, 0.0, 1.0) + offsets;
* v_texCoord = a_texCoord;
* v_opacity = a_opacity;
* v_color = a_color;
* }
* ```
*
* * Fragment shader:
* ```
* precision mediump float;
*
* uniform sampler2D u_texture;
*
* varying vec2 v_texCoord;
* varying float v_opacity;
* varying vec4 v_color;
*
* void main(void) {
* if (v_opacity == 0.0) {
* discard;
* }
* vec4 textureColor = texture2D(u_texture, v_texCoord);
* gl_FragColor = v_color * textureColor;
* gl_FragColor.a *= v_opacity;
* gl_FragColor.rgb *= gl_FragColor.a;
* }
* ```
*
* @api
*/
class WebGLPointsLayerRenderer extends WebGLLayerRenderer {
/**
* @param {import("../../layer/Vector.js").default} vectorLayer Vector layer.
* @param {Options=} [opt_options] Options.
*/
constructor(vectorLayer, opt_options) {
const options = opt_options || {};
const uniforms = options.uniforms || {};
uniforms.u_texture = options.texture || getBlankImageData();
const projectionMatrixTransform = createTransform();
uniforms[DefaultUniform.PROJECTION_MATRIX] = projectionMatrixTransform;
super(vectorLayer, {
uniforms: uniforms,
postProcesses: options.postProcesses
});
this.sourceRevision_ = -1;
this.verticesBuffer_ = new WebGLArrayBuffer(ARRAY_BUFFER, DYNAMIC_DRAW);
this.hitVerticesBuffer_ = new WebGLArrayBuffer(ARRAY_BUFFER, DYNAMIC_DRAW);
this.indicesBuffer_ = new WebGLArrayBuffer(ELEMENT_ARRAY_BUFFER, DYNAMIC_DRAW);
this.program_ = this.helper.getProgram(
options.fragmentShader || FRAGMENT_SHADER,
options.vertexShader || VERTEX_SHADER
);
this.helper.useProgram(this.program_);
this.sizeCallback_ = options.sizeCallback || function() {
return 1;
};
this.coordCallback_ = options.coordCallback || function(feature, index) {
const geom = feature.getGeometry();
return geom.getCoordinates()[index];
};
this.opacityCallback_ = options.opacityCallback || function() {
return 1;
};
this.texCoordCallback_ = options.texCoordCallback || function(feature, index) {
return index < 2 ? 0 : 1;
};
this.colorArray_ = [1, 1, 1, 1];
this.colorCallback_ = options.colorCallback || function(feature, color) {
return this.colorArray_;
};
this.rotateWithViewCallback_ = options.rotateWithViewCallback || function() {
return false;
};
this.previousExtent_ = createEmpty();
/**
* This transform is updated on every frame and is the composition of:
* - invert of the world->screen transform that was used when rebuilding buffers (see `this.renderTransform_`)
* - current world->screen transform
* @type {import("../../transform.js").Transform}
* @private
*/
this.currentTransform_ = projectionMatrixTransform;
/**
* This transform is updated when buffers are rebuilt and converts world space coordinates to screen space
* @type {import("../../transform.js").Transform}
* @private
*/
this.renderTransform_ = createTransform();
/**
* @type {import("../../transform.js").Transform}
* @private
*/
this.invertRenderTransform_ = createTransform();
/**
* @type {Float32Array}
* @private
*/
this.renderInstructions_ = new Float32Array(0);
/**
* @type {import("../../transform.js").Transform}
* @private
*/
this.hitRenderTransform_ = createTransform();
/**
* @type {import("../../transform.js").Transform}
* @private
*/
this.invertHitRenderTransform_ = createTransform();
/**
* These instructions are used for hit detection
* @type {Float32Array}
* @private
*/
this.hitRenderInstructions_ = new Float32Array(0);
this.worker_ = createWebGLWorker();
this.worker_.addEventListener('message', function(event) {
const received = event.data;
if (received.type === WebGLWorkerMessageType.GENERATE_BUFFERS) {
const projectionTransform = received.projectionTransform;
if (received.hitDetection) {
this.hitVerticesBuffer_.fromArrayBuffer(received.vertexBuffer);
this.helper.flushBufferData(this.hitVerticesBuffer_);
} else {
this.verticesBuffer_.fromArrayBuffer(received.vertexBuffer);
this.helper.flushBufferData(this.verticesBuffer_);
}
this.indicesBuffer_.fromArrayBuffer(received.indexBuffer);
this.helper.flushBufferData(this.indicesBuffer_);
if (received.hitDetection) {
this.hitRenderTransform_ = projectionTransform;
makeInverseTransform(this.invertHitRenderTransform_, this.hitRenderTransform_);
this.hitRenderInstructions_ = new Float32Array(event.data.renderInstructions);
} else {
this.renderTransform_ = projectionTransform;
makeInverseTransform(this.invertRenderTransform_, this.renderTransform_);
this.renderInstructions_ = new Float32Array(event.data.renderInstructions);
}
}
}.bind(this));
}
/**
* @inheritDoc
*/
disposeInternal() {
super.disposeInternal();
}
/**
* @inheritDoc
*/
renderFrame(frameState) {
const renderCount = this.indicesBuffer_.getArray() ? this.indicesBuffer_.getArray().length : 0;
this.helper.drawElements(0, renderCount);
this.helper.finalizeDraw(frameState);
const canvas = this.helper.getCanvas();
const layerState = frameState.layerStatesArray[frameState.layerIndex];
const opacity = layerState.opacity;
if (opacity !== parseFloat(canvas.style.opacity)) {
canvas.style.opacity = opacity;
}
return canvas;
}
/**
* @inheritDoc
*/
prepareFrame(frameState) {
const vectorLayer = /** @type {import("../../layer/Vector.js").default} */ (this.getLayer());
const vectorSource = vectorLayer.getSource();
const viewState = frameState.viewState;
const stride = POINT_VERTEX_STRIDE;
// the source has changed: clear the feature cache & reload features
const sourceChanged = this.sourceRevision_ < vectorSource.getRevision();
if (sourceChanged) {
this.sourceRevision_ = vectorSource.getRevision();
const projection = viewState.projection;
const resolution = viewState.resolution;
vectorSource.loadFeatures([-Infinity, -Infinity, Infinity, Infinity], resolution, projection);
}
const viewNotMoving = !frameState.viewHints[ViewHint.ANIMATING] && !frameState.viewHints[ViewHint.INTERACTING];
const extentChanged = !equals(this.previousExtent_, frameState.extent);
if ((sourceChanged || extentChanged) && viewNotMoving) {
this.rebuildBuffers_(frameState);
this.previousExtent_ = frameState.extent.slice();
}
// apply the current projection transform with the invert of the one used to fill buffers
this.helper.makeProjectionTransform(frameState, this.currentTransform_);
multiplyTransform(this.currentTransform_, this.invertRenderTransform_);
this.helper.prepareDraw(frameState);
// write new data
this.helper.bindBuffer(this.verticesBuffer_);
this.helper.bindBuffer(this.indicesBuffer_);
const bytesPerFloat = Float32Array.BYTES_PER_ELEMENT;
this.helper.enableAttributeArray(DefaultAttrib.POSITION, 2, FLOAT, bytesPerFloat * stride, 0);
this.helper.enableAttributeArray(DefaultAttrib.OFFSETS, 2, FLOAT, bytesPerFloat * stride, bytesPerFloat * 2);
this.helper.enableAttributeArray(DefaultAttrib.TEX_COORD, 2, FLOAT, bytesPerFloat * stride, bytesPerFloat * 4);
this.helper.enableAttributeArray(DefaultAttrib.OPACITY, 1, FLOAT, bytesPerFloat * stride, bytesPerFloat * 6);
this.helper.enableAttributeArray(DefaultAttrib.ROTATE_WITH_VIEW, 1, FLOAT, bytesPerFloat * stride, bytesPerFloat * 7);
this.helper.enableAttributeArray(DefaultAttrib.COLOR, 4, FLOAT, bytesPerFloat * stride, bytesPerFloat * 8);
return true;
}
/**
* Rebuild internal webgl buffers based on current view extent; costly, should not be called too much
* @param {import("../../PluggableMap").FrameState} frameState Frame state.
* @private
*/
rebuildBuffers_(frameState) {
const vectorLayer = /** @type {import("../../layer/Vector.js").default} */ (this.getLayer());
const vectorSource = vectorLayer.getSource();
// saves the projection transform for the current frame state
const projectionTransform = createTransform();
this.helper.makeProjectionTransform(frameState, projectionTransform);
const features = vectorSource.getFeatures();
const totalInstructionsCount = POINT_INSTRUCTIONS_COUNT * features.length;
if (!this.renderInstructions_ || this.renderInstructions_.length !== totalInstructionsCount) {
this.renderInstructions_ = new Float32Array(totalInstructionsCount);
}
if (!this.hitRenderInstructions_ || this.hitRenderInstructions_.length !== totalInstructionsCount) {
this.hitRenderInstructions_ = new Float32Array(totalInstructionsCount);
}
// loop on features to fill the buffer
let feature;
const tmpCoords = [];
const tmpColor = [];
let elementIndex = 0;
let u0, v0, u1, v1, size, opacity, rotateWithView, color;
for (let i = 0; i < features.length; i++) {
feature = features[i];
if (!feature.getGeometry() || feature.getGeometry().getType() !== GeometryType.POINT) {
continue;
}
tmpCoords[0] = this.coordCallback_(feature, 0);
tmpCoords[1] = this.coordCallback_(feature, 1);
applyTransform(projectionTransform, tmpCoords);
u0 = this.texCoordCallback_(feature, 0);
v0 = this.texCoordCallback_(feature, 1);
u1 = this.texCoordCallback_(feature, 2);
v1 = this.texCoordCallback_(feature, 3);
size = this.sizeCallback_(feature);
opacity = this.opacityCallback_(feature);
rotateWithView = this.rotateWithViewCallback_(feature);
color = this.colorCallback_(feature, this.colorArray_);
writePointFeatureInstructions(
this.renderInstructions_,
elementIndex,
tmpCoords[0],
tmpCoords[1],
u0,
v0,
u1,
v1,
size,
opacity,
rotateWithView,
color
);
elementIndex = writePointFeatureInstructions(
this.hitRenderInstructions_,
elementIndex,
tmpCoords[0],
tmpCoords[1],
u0,
v0,
u1,
v1,
size,
opacity,
rotateWithView,
colorEncodeId(parseInt(getUid(feature)), tmpColor)
);
}
/** @type import('./Layer').WebGLWorkerGenerateBuffersMessage */
const message = {
type: WebGLWorkerMessageType.GENERATE_BUFFERS,
renderInstructions: this.renderInstructions_.buffer
};
// additional properties will be sent back as-is by the worker
message['projectionTransform'] = projectionTransform;
this.worker_.postMessage(message, [this.renderInstructions_.buffer]);
this.renderInstructions_ = null;
/** @type import('./Layer').WebGLWorkerGenerateBuffersMessage */
const hitMessage = {
type: WebGLWorkerMessageType.GENERATE_BUFFERS,
renderInstructions: this.hitRenderInstructions_.buffer,
useShortIndices: !this.helper.getElementIndexUintEnabled()
};
hitMessage['projectionTransform'] = projectionTransform;
hitMessage['hitDetection'] = true;
this.worker_.postMessage(hitMessage, [this.hitRenderInstructions_.buffer]);
this.hitRenderInstructions_ = null;
}
}
export default WebGLPointsLayerRenderer;