Files
openlayers/src/ol/renderer/webgl/ImageLayer.js
Tim Schaub 4cb5dc695b Merge pull request #8774 from schmidtk/ts-renderer-webgl
Fix type check errors in ol/renderer/webgl
2018-10-03 03:48:07 -06:00

341 lines
11 KiB
JavaScript

/**
* @module ol/renderer/webgl/ImageLayer
*/
import {ENABLE_RASTER_REPROJECTION} from '../../reproj/common.js';
import {TRUE, VOID} from '../../functions.js';
import LayerType from '../../LayerType.js';
import ViewHint from '../../ViewHint.js';
import {createCanvasContext2D} from '../../dom.js';
import {getIntersection, isEmpty} from '../../extent.js';
import WebGLLayerRenderer from '../webgl/Layer.js';
import {
create as createTransform,
rotate as rotateTransform,
translate as translateTransform,
scale as scaleTransform,
reset as resetTransform,
apply as applyTransform,
invert as invertTransform,
multiply as multiplyTransform
} from '../../transform.js';
import {CLAMP_TO_EDGE} from '../../webgl.js';
import {createTexture} from '../../webgl/Context.js';
/**
* @classdesc
* WebGL renderer for image layers.
* @api
*/
class WebGLImageLayerRenderer extends WebGLLayerRenderer {
/**
* @param {import("./Map.js").default} mapRenderer Map renderer.
* @param {import("../../layer/Image.js").default} imageLayer Tile layer.
*/
constructor(mapRenderer, imageLayer) {
super(mapRenderer, imageLayer);
/**
* The last rendered image.
* @private
* @type {?import("../../ImageBase.js").default}
*/
this.image_ = null;
/**
* @private
* @type {CanvasRenderingContext2D}
*/
this.hitCanvasContext_ = null;
/**
* @private
* @type {?import("../../transform.js").Transform}
*/
this.hitTransformationMatrix_ = null;
}
/**
* @param {import("../../ImageBase.js").default} image Image.
* @private
* @return {WebGLTexture} Texture.
*/
createTexture_(image) {
// We meet the conditions to work with non-power of two textures.
// http://www.khronos.org/webgl/wiki/WebGL_and_OpenGL_Differences#Non-Power_of_Two_Texture_Support
// http://learningwebgl.com/blog/?p=2101
const imageElement = image.getImage();
const gl = this.mapRenderer.getGL();
return createTexture(
gl, imageElement, CLAMP_TO_EDGE, CLAMP_TO_EDGE);
}
/**
* @inheritDoc
*/
forEachFeatureAtCoordinate(coordinate, frameState, hitTolerance, callback, thisArg) {
const layer = this.getLayer();
const source = layer.getSource();
const resolution = frameState.viewState.resolution;
const rotation = frameState.viewState.rotation;
const skippedFeatureUids = frameState.skippedFeatureUids;
return source.forEachFeatureAtCoordinate(
coordinate, resolution, rotation, hitTolerance, skippedFeatureUids,
/**
* @param {import("../../Feature.js").FeatureLike} feature Feature.
* @return {?} Callback result.
*/
function(feature) {
return callback.call(thisArg, feature, layer);
});
}
/**
* @inheritDoc
*/
prepareFrame(frameState, layerState, context) {
const gl = this.mapRenderer.getGL();
const pixelRatio = frameState.pixelRatio;
const viewState = frameState.viewState;
const viewCenter = viewState.center;
const viewResolution = viewState.resolution;
const viewRotation = viewState.rotation;
let image = this.image_;
let texture = this.texture;
const imageLayer = /** @type {import("../../layer/Image.js").default} */ (this.getLayer());
const imageSource = /** @type {import("../../source/Image.js").default} */ (imageLayer.getSource());
const hints = frameState.viewHints;
let renderedExtent = frameState.extent;
if (layerState.extent !== undefined) {
renderedExtent = getIntersection(renderedExtent, layerState.extent);
}
if (!hints[ViewHint.ANIMATING] && !hints[ViewHint.INTERACTING] &&
!isEmpty(renderedExtent)) {
let projection = viewState.projection;
if (!ENABLE_RASTER_REPROJECTION) {
const sourceProjection = imageSource.getProjection();
if (sourceProjection) {
projection = sourceProjection;
}
}
const image_ = imageSource.getImage(renderedExtent, viewResolution,
pixelRatio, projection);
if (image_) {
const loaded = this.loadImage(image_);
if (loaded) {
image = image_;
texture = this.createTexture_(image_);
if (this.texture) {
/**
* @param {WebGLRenderingContext} gl GL.
* @param {WebGLTexture} texture Texture.
*/
const postRenderFunction = function(gl, texture) {
if (!gl.isContextLost()) {
gl.deleteTexture(texture);
}
}.bind(null, gl, this.texture);
frameState.postRenderFunctions.push(
/** @type {import("../../PluggableMap.js").PostRenderFunction} */ (postRenderFunction)
);
}
}
}
}
if (image) {
const canvas = this.mapRenderer.getContext().getCanvas();
this.updateProjectionMatrix_(canvas.width, canvas.height,
pixelRatio, viewCenter, viewResolution, viewRotation,
image.getExtent());
this.hitTransformationMatrix_ = null;
// Translate and scale to flip the Y coord.
const texCoordMatrix = this.texCoordMatrix;
resetTransform(texCoordMatrix);
scaleTransform(texCoordMatrix, 1, -1);
translateTransform(texCoordMatrix, 0, -1);
this.image_ = image;
this.texture = texture;
}
return !!image;
}
/**
* @param {number} canvasWidth Canvas width.
* @param {number} canvasHeight Canvas height.
* @param {number} pixelRatio Pixel ratio.
* @param {import("../../coordinate.js").Coordinate} viewCenter View center.
* @param {number} viewResolution View resolution.
* @param {number} viewRotation View rotation.
* @param {import("../../extent.js").Extent} imageExtent Image extent.
* @private
*/
updateProjectionMatrix_(
canvasWidth,
canvasHeight,
pixelRatio,
viewCenter,
viewResolution,
viewRotation,
imageExtent
) {
const canvasExtentWidth = canvasWidth * viewResolution;
const canvasExtentHeight = canvasHeight * viewResolution;
const projectionMatrix = this.projectionMatrix;
resetTransform(projectionMatrix);
scaleTransform(projectionMatrix,
pixelRatio * 2 / canvasExtentWidth,
pixelRatio * 2 / canvasExtentHeight);
rotateTransform(projectionMatrix, -viewRotation);
translateTransform(projectionMatrix,
imageExtent[0] - viewCenter[0],
imageExtent[1] - viewCenter[1]);
scaleTransform(projectionMatrix,
(imageExtent[2] - imageExtent[0]) / 2,
(imageExtent[3] - imageExtent[1]) / 2);
translateTransform(projectionMatrix, 1, 1);
}
/**
* @inheritDoc
*/
hasFeatureAtCoordinate(coordinate, frameState) {
const hasFeature = this.forEachFeatureAtCoordinate(coordinate, frameState, 0, TRUE, this);
return hasFeature !== undefined;
}
/**
* @inheritDoc
*/
forEachLayerAtPixel(pixel, frameState, callback, thisArg) {
if (!this.image_ || !this.image_.getImage()) {
return undefined;
}
if (this.getLayer().getSource().forEachFeatureAtCoordinate !== VOID) {
// for ImageCanvas sources use the original hit-detection logic,
// so that for example also transparent polygons are detected
const coordinate = applyTransform(
frameState.pixelToCoordinateTransform, pixel.slice());
const hasFeature = this.forEachFeatureAtCoordinate(coordinate, frameState, 0, TRUE, this);
if (hasFeature) {
return callback.call(thisArg, this.getLayer(), null);
} else {
return undefined;
}
} else {
const imageSize =
[this.image_.getImage().width, this.image_.getImage().height];
if (!this.hitTransformationMatrix_) {
this.hitTransformationMatrix_ = this.getHitTransformationMatrix_(
frameState.size, imageSize);
}
const pixelOnFrameBuffer = applyTransform(
this.hitTransformationMatrix_, pixel.slice());
if (pixelOnFrameBuffer[0] < 0 || pixelOnFrameBuffer[0] > imageSize[0] ||
pixelOnFrameBuffer[1] < 0 || pixelOnFrameBuffer[1] > imageSize[1]) {
// outside the image, no need to check
return undefined;
}
if (!this.hitCanvasContext_) {
this.hitCanvasContext_ = createCanvasContext2D(1, 1);
}
this.hitCanvasContext_.clearRect(0, 0, 1, 1);
this.hitCanvasContext_.drawImage(this.image_.getImage(),
pixelOnFrameBuffer[0], pixelOnFrameBuffer[1], 1, 1, 0, 0, 1, 1);
const imageData = this.hitCanvasContext_.getImageData(0, 0, 1, 1).data;
if (imageData[3] > 0) {
return callback.call(thisArg, this.getLayer(), imageData);
} else {
return undefined;
}
}
}
/**
* The transformation matrix to get the pixel on the image for a
* pixel on the map.
* @param {import("../../size.js").Size} mapSize The map size.
* @param {import("../../size.js").Size} imageSize The image size.
* @return {import("../../transform.js").Transform} The transformation matrix.
* @private
*/
getHitTransformationMatrix_(mapSize, imageSize) {
// the first matrix takes a map pixel, flips the y-axis and scales to
// a range between -1 ... 1
const mapCoordTransform = createTransform();
translateTransform(mapCoordTransform, -1, -1);
scaleTransform(mapCoordTransform, 2 / mapSize[0], 2 / mapSize[1]);
translateTransform(mapCoordTransform, 0, mapSize[1]);
scaleTransform(mapCoordTransform, 1, -1);
// the second matrix is the inverse of the projection matrix used in the
// shader for drawing
const projectionMatrixInv = invertTransform(this.projectionMatrix.slice());
// the third matrix scales to the image dimensions and flips the y-axis again
const transform = createTransform();
translateTransform(transform, 0, imageSize[1]);
scaleTransform(transform, 1, -1);
scaleTransform(transform, imageSize[0] / 2, imageSize[1] / 2);
translateTransform(transform, 1, 1);
multiplyTransform(transform, projectionMatrixInv);
multiplyTransform(transform, mapCoordTransform);
return transform;
}
}
/**
* Determine if this renderer handles the provided layer.
* @param {import("../../layer/Layer.js").default} layer The candidate layer.
* @return {boolean} The renderer can render the layer.
*/
WebGLImageLayerRenderer['handles'] = function(layer) {
return layer.getType() === LayerType.IMAGE;
};
/**
* Create a layer renderer.
* @param {import("../Map.js").default} mapRenderer The map renderer.
* @param {import("../../layer/Layer.js").default} layer The layer to be rendererd.
* @return {WebGLImageLayerRenderer} The layer renderer.
*/
WebGLImageLayerRenderer['create'] = function(mapRenderer, layer) {
return new WebGLImageLayerRenderer(
/** @type {import("./Map.js").default} */ (mapRenderer),
/** @type {import("../../layer/Image.js").default} */ (layer)
);
};
export default WebGLImageLayerRenderer;