openseadragon/test/demo/webgldemodrawer.js

1238 lines
52 KiB
JavaScript

// THIS CODE OVERWRITES THE ORIGINAL VERSION FOR FASTER TESTING
// i.e. it doesn't need to be re-built with grunt after every save.
/*
* OpenSeadragon - WebGLDrawer
*
* Copyright (C) 2009 CodePlex Foundation
* Copyright (C) 2010-2023 OpenSeadragon contributors
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are
* met:
*
* - Redistributions of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
*
* - Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* - Neither the name of CodePlex Foundation nor the names of its
* contributors may be used to endorse or promote products derived from
* this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
* OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
* TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
* PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
* LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
* NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
(function( $ ){
// internal class Mat3: implements matrix operations
// Modified from https://webglfundamentals.org/webgl/lessons/webgl-2d-matrices.html
class Mat3{
constructor(values){
if(!values) {
values = [
0, 0, 0,
0, 0, 0,
0, 0, 0
];
}
this.values = values;
}
static makeIdentity(){
return new Mat3([
1, 0, 0,
0, 1, 0,
0, 0, 1
]);
}
static makeTranslation(tx, ty) {
return new Mat3([
1, 0, 0,
0, 1, 0,
tx, ty, 1,
]);
}
static makeRotation(angleInRadians) {
var c = Math.cos(angleInRadians);
var s = Math.sin(angleInRadians);
return new Mat3([
c, -s, 0,
s, c, 0,
0, 0, 1,
]);
}
static makeScaling(sx, sy) {
return new Mat3([
sx, 0, 0,
0, sy, 0,
0, 0, 1,
]);
}
multiply(other) {
let a = this.values;
let b = other.values;
var a00 = a[0 * 3 + 0];
var a01 = a[0 * 3 + 1];
var a02 = a[0 * 3 + 2];
var a10 = a[1 * 3 + 0];
var a11 = a[1 * 3 + 1];
var a12 = a[1 * 3 + 2];
var a20 = a[2 * 3 + 0];
var a21 = a[2 * 3 + 1];
var a22 = a[2 * 3 + 2];
var b00 = b[0 * 3 + 0];
var b01 = b[0 * 3 + 1];
var b02 = b[0 * 3 + 2];
var b10 = b[1 * 3 + 0];
var b11 = b[1 * 3 + 1];
var b12 = b[1 * 3 + 2];
var b20 = b[2 * 3 + 0];
var b21 = b[2 * 3 + 1];
var b22 = b[2 * 3 + 2];
return new Mat3([
b00 * a00 + b01 * a10 + b02 * a20,
b00 * a01 + b01 * a11 + b02 * a21,
b00 * a02 + b01 * a12 + b02 * a22,
b10 * a00 + b11 * a10 + b12 * a20,
b10 * a01 + b11 * a11 + b12 * a21,
b10 * a02 + b11 * a12 + b12 * a22,
b20 * a00 + b21 * a10 + b22 * a20,
b20 * a01 + b21 * a11 + b22 * a21,
b20 * a02 + b21 * a12 + b22 * a22,
]);
}
}
/**
* @class WebGLDrawer
* @memberof OpenSeadragon
* @classdesc Default implementation of WebGLDrawer for an {@link OpenSeadragon.Viewer}.
* @param {Object} options - Options for this Drawer.
* @param {OpenSeadragon.Viewer} options.viewer - The Viewer that owns this Drawer.
* @param {OpenSeadragon.Viewport} options.viewport - Reference to Viewer viewport.
* @param {Element} options.element - Parent element.
* @param {Number} [options.debugGridColor] - See debugGridColor in {@link OpenSeadragon.Options} for details.
*/
$.WebGLDrawer = class WebGLDrawer extends OpenSeadragon.DrawerBase{
constructor(options){
super(options);
this.destroyed = false;
// private members
this._TextureMap = new Map();
this._TileMap = new Map();
this._gl = null;
this._firstPass = null;
this._secondPass = null;
this._glFrameBuffer = null;
this._renderToTexture = null;
this._glFramebufferToCanvasTransform = null;
this._outputCanvas = null;
this._outputContext = null;
this._clippingCanvas = null;
this._clippingContext = null;
this._renderingCanvas = null;
// Add listeners for events that require modifying the scene or camera
this.viewer.addHandler("tile-ready", ev => this._tileReadyHandler(ev));
this.viewer.addHandler("image-unloaded", ev => this._imageUnloadedHandler(ev));
// this.viewer is set by parent constructor
// this.canvas is set by parent constructor, created and appended to the viewer container element
this._setupCanvases();
this._setupRenderer();
this.context = this._outputContext; // API required by tests
}
// Public API required by all Drawer implementations
/**
* Clean up the renderer, removing all resources
*/
destroy(){
if(this.destroyed){
return;
}
// clear all resources used by the renderer, geometries, textures etc
let gl = this._gl;
// adapted from https://stackoverflow.com/a/23606581/1214731
var numTextureUnits = gl.getParameter(gl.MAX_TEXTURE_IMAGE_UNITS);
for (let unit = 0; unit < numTextureUnits; ++unit) {
gl.activeTexture(gl.TEXTURE0 + unit);
gl.bindTexture(gl.TEXTURE_2D, null);
gl.bindTexture(gl.TEXTURE_CUBE_MAP, null);
}
gl.bindBuffer(gl.ARRAY_BUFFER, null);
gl.bindBuffer(gl.ELEMENT_ARRAY_BUFFER, null);
gl.bindRenderbuffer(gl.RENDERBUFFER, null);
gl.bindFramebuffer(gl.FRAMEBUFFER, null);
let canvases = Array.from(this._TextureMap.keys());
canvases.forEach(canvas => {
this._cleanupImageData(canvas); // deletes texture, removes from _TextureMap
});
// Delete all our created resources
gl.deleteBuffer(this._secondPass.bufferOutputPosition);
gl.deleteFramebuffer(this._glFrameBuffer);
// TODO: if/when render buffers or frame buffers are used, release them:
// gl.deleteRenderbuffer(someRenderbuffer);
// gl.deleteFramebuffer(someFramebuffer);
// make canvases 1 x 1 px and delete references
this._renderingCanvas.width = this._renderingCanvas.height = 1;
this._clippingCanvas.width = this._clippingCanvas.height = 1;
this._outputCanvas.width = this._outputCanvas.height = 1;
this._renderingCanvas = null;
this._clippingCanvas = this._clippingContext = null;
this._outputCanvas = this._outputContext = null;
let ext = gl.getExtension('WEBGL_lose_context');
if(ext){
ext.loseContext();
}
// set our webgl context reference to null to enable garbage collection
this._gl = null;
// set our destroyed flag to true
this.destroyed = true;
}
// Public API required by all Drawer implementations
/**
*
* @returns true if the drawer supports rotation
*/
canRotate(){
return true;
}
// Public API required by all Drawer implementations
/**
* @returns {Boolean} returns true if canvas and webgl are supported
*/
static isSupported(){
let canvasElement = document.createElement( 'canvas' );
let webglContext = $.isFunction( canvasElement.getContext ) &&
canvasElement.getContext( 'webgl' );
let ext = webglContext.getExtension('WEBGL_lose_context');
if(ext){
ext.loseContext();
}
return !!( webglContext );
}
getType(){
return 'webgl';
}
/**
* create the HTML element (canvas in this case) that the image will be drawn into
* @returns {Element} the canvas to draw into
*/
createDrawingElement(){
let canvas = $.makeNeutralElement("canvas");
let viewportSize = this._calculateCanvasSize();
canvas.width = viewportSize.x;
canvas.height = viewportSize.y;
return canvas;
}
/**
*
* @param {Array} tiledImages Array of TiledImage objects to draw
*/
draw(tiledImages){
let gl = this._gl;
let viewport = {
bounds: this.viewport.getBoundsNoRotate(true),
center: this.viewport.getCenter(true),
rotation: this.viewport.getRotation(true) * Math.PI / 180
};
let flipMultiplier = this.viewport.flipped ? -1 : 1;
// calculate view matrix for viewer
let posMatrix = Mat3.makeTranslation(-viewport.center.x, -viewport.center.y);
let scaleMatrix = Mat3.makeScaling(2 / viewport.bounds.width * flipMultiplier, -2 / viewport.bounds.height);
let rotMatrix = Mat3.makeRotation(-viewport.rotation);
let viewMatrix = scaleMatrix.multiply(rotMatrix).multiply(posMatrix);
gl.bindFramebuffer(gl.FRAMEBUFFER, null);
gl.clear(gl.COLOR_BUFFER_BIT); // clear the back buffer
// clear the output canvas
this._outputContext.clearRect(0, 0, this._outputCanvas.width, this._outputCanvas.height);
let renderingBufferHasImageData = false;
//iterate over tiled images and draw each one using a two-pass rendering pipeline if needed
tiledImages.forEach( (tiledImage, tiledImageIndex) => {
let useContext2dPipeline = ( tiledImage.compositeOperation ||
this.viewer.compositeOperation ||
tiledImage._clip ||
tiledImage._croppingPolygons ||
tiledImage.debugMode
);
let useTwoPassRendering = useContext2dPipeline ||(tiledImage.opacity < 1); // TODO: check hasTransparency in addition to opacity
let tilesToDraw = tiledImage.getTilesToDraw();
if(tilesToDraw.length === 0){
return;
}
// using the context2d pipeline requires a clean rendering (back) buffer to start
if(useContext2dPipeline){
// if the rendering buffer has image data currently, write it to the output canvas now and clear it
if(renderingBufferHasImageData){
this._outputContext.drawImage(this._renderingCanvas, 0, 0);
}
// clear the buffer
gl.bindFramebuffer(gl.FRAMEBUFFER, null);
gl.clear(gl.COLOR_BUFFER_BIT); // clear the back buffer
}
// First rendering pass: compose tiles that make up this tiledImage
gl.useProgram(this._firstPass.shaderProgram);
// bind to the framebuffer for render-to-texture if using two-pass rendering, otherwise back buffer (null)
if(useTwoPassRendering){
gl.bindFramebuffer(gl.FRAMEBUFFER, this._glFrameBuffer);
// clear the buffer to draw a new image
gl.clear(gl.COLOR_BUFFER_BIT);
} else {
gl.bindFramebuffer(gl.FRAMEBUFFER, null);
// no need to clear, just draw on top of the existing pixels
}
let overallMatrix = viewMatrix;
let imageRotation = tiledImage.getRotation(true);
// if needed, handle the tiledImage being rotated
if( imageRotation % 360 !== 0){
let imageRotationMatrix = Mat3.makeRotation(-imageRotation * Math.PI / 180);
let imageCenter = tiledImage.getBoundsNoRotate(true).getCenter();
let t1 = Mat3.makeTranslation(imageCenter.x, imageCenter.y);
let t2 = Mat3.makeTranslation(-imageCenter.x, -imageCenter.y);
// update the view matrix to account for this image's rotation
let localMatrix = t1.multiply(imageRotationMatrix).multiply(t2);
overallMatrix = viewMatrix.multiply(localMatrix);
}
let maxTextures = this._gl.getParameter(this._gl.MAX_TEXTURE_IMAGE_UNITS);
let texturePositionArray = new Float32Array(maxTextures * 12); // 6 vertices (2 triangles) x 2 coordinates per vertex
let textureDataArray = new Array(maxTextures);
let matrixArray = new Array(maxTextures);
let opacityArray = new Array(maxTextures);
// iterate over tiles and add data for each one to the buffers
for(let tileIndex = 0; tileIndex < tilesToDraw.length; tileIndex++){
let tile = tilesToDraw[tileIndex].tile;
let index = tileIndex % maxTextures;
let tileContext = tile.getCanvasContext();
let textureInfo = tileContext ? this._TextureMap.get(tileContext.canvas) : null;
if(textureInfo){
this._getTileData(tile, tiledImage, textureInfo, overallMatrix, index, texturePositionArray, textureDataArray, matrixArray, opacityArray);
} else {
// console.log('No tile info', tile);
}
if( (index === maxTextures - 1) || (tileIndex === tilesToDraw.length - 1)){
// We've filled up the buffers: time to draw this set of tiles
// bind each tile's texture to the appropriate gl.TEXTURE#
for(let i = 0; i <= index; i++){
gl.activeTexture(gl.TEXTURE0 + i);
gl.bindTexture(gl.TEXTURE_2D, textureDataArray[i]);
}
// set the buffer data for the texture coordinates to use for each tile
gl.bindBuffer(gl.ARRAY_BUFFER, this._firstPass.bufferTexturePosition);
gl.bufferData(gl.ARRAY_BUFFER, texturePositionArray, gl.DYNAMIC_DRAW);
// set the transform matrix uniform for each tile
matrixArray.forEach( (matrix, index) => {
gl.uniformMatrix3fv(this._firstPass.uTransformMatrices[index], false, matrix);
});
// set the opacity uniform for each tile
gl.uniform1fv(this._firstPass.uOpacities, new Float32Array(opacityArray));
// bind vertex buffers and (re)set attributes before calling gl.drawArrays()
gl.bindBuffer(gl.ARRAY_BUFFER, this._firstPass.bufferOutputPosition);
gl.vertexAttribPointer(this._firstPass.aOutputPosition, 2, gl.FLOAT, false, 0, 0);
gl.bindBuffer(gl.ARRAY_BUFFER, this._firstPass.bufferTexturePosition);
gl.vertexAttribPointer(this._firstPass.aTexturePosition, 2, gl.FLOAT, false, 0, 0);
gl.bindBuffer(gl.ARRAY_BUFFER, this._firstPass.bufferIndex);
gl.vertexAttribPointer(this._firstPass.aIndex, 1, gl.FLOAT, false, 0, 0);
// Draw! 6 vertices per tile (2 triangles per rectangle)
gl.drawArrays(gl.TRIANGLES, 0, 6 * (index + 1) );
}
}
// gl.flush(); // is this necessary?
if(useTwoPassRendering){
// Second rendering pass: Render the tiled image from the framebuffer into the back buffer
gl.useProgram(this._secondPass.shaderProgram);
// set the rendering target to the back buffer (null)
gl.bindFramebuffer(gl.FRAMEBUFFER, null);
// bind the rendered texture from the first pass to use during this second pass
gl.activeTexture(gl.TEXTURE0);
gl.bindTexture(gl.TEXTURE_2D, this._renderToTexture);
// set opacity to the value for the current tiledImage
this._gl.uniform1f(this._secondPass.uOpacityMultiplier, tiledImage.opacity);
// bind buffers and set attributes before calling gl.drawArrays
gl.bindBuffer(gl.ARRAY_BUFFER, this._secondPass.bufferTexturePosition);
gl.vertexAttribPointer(this._secondPass.aTexturePosition, 2, gl.FLOAT, false, 0, 0);
gl.bindBuffer(gl.ARRAY_BUFFER, this._secondPass.bufferOutputPosition);
gl.vertexAttribPointer(this._firstPass.aOutputPosition, 2, gl.FLOAT, false, 0, 0);
// Draw the quad (two triangles)
gl.drawArrays(gl.TRIANGLES, 0, 6);
// TODO: is this the mechanism we want to use here?
// iterate over any filters - filters can use this._renderToTexture to get rendered data if desired
let filters = this.filters || [];
for(let fi = 0; fi < filters.length; fi++){
let filter = this.filters[fi];
if(filter.apply){
filter.apply(gl); // filter.apply should write data on top of the backbuffer (bound above)
}
}
}
renderingBufferHasImageData = true;
// gl.flush(); //make sure drawing to the output buffer of the rendering canvas is complete. Is this necessary?
if(useContext2dPipeline){
// draw from the rendering canvas onto the output canvas, clipping/cropping if needed.
this._applyContext2dPipeline(tiledImage, tilesToDraw, tiledImageIndex);
renderingBufferHasImageData = false;
// clear the buffer
gl.bindFramebuffer(gl.FRAMEBUFFER, null);
gl.clear(gl.COLOR_BUFFER_BIT); // clear the back buffer
}
// Fire tiled-image-drawn event.
// TODO: the image data may not be on the output canvas yet!!
if( this.viewer ){
/**
* Raised when a tiled image is drawn to the canvas. Only valid
* for webgl drawer.
*
* @event tiled-image-drawn
* @memberof OpenSeadragon.Viewer
* @type {object}
* @property {OpenSeadragon.Viewer} eventSource - A reference to the Viewer which raised the event.
* @property {OpenSeadragon.TiledImage} tiledImage - Which TiledImage is being drawn.
* @property {Array} tiles - An array of Tile objects that were drawn.
* @property {?Object} userData - Arbitrary subscriber-defined object.
*/
this.viewer.raiseEvent( 'tiled-image-drawn', {
tiledImage: tiledImage,
tiles: tilesToDraw.map(info => info.tile),
});
}
});
// TODO: the line below is a test!
if(renderingBufferHasImageData){
this._outputContext.drawImage(this._renderingCanvas, 0, 0);
}
}
// Public API required by all Drawer implementations
/**
* Set the context2d imageSmoothingEnabled parameter
* @param {Boolean} enabled
*/
setImageSmoothingEnabled(enabled){
this._clippingContext.imageSmoothingEnabled = enabled;
this._outputContext.imageSmoothingEnabled = enabled;
}
/**
* Draw a rect onto the output canvas for debugging purposes
* @param {OpenSeadragon.Rect} rect
*/
drawDebuggingRect(rect){
let context = this._outputContext;
context.save();
context.lineWidth = 2 * $.pixelDensityRatio;
context.strokeStyle = this.debugGridColor[0];
context.fillStyle = this.debugGridColor[0];
context.strokeRect(
rect.x * $.pixelDensityRatio,
rect.y * $.pixelDensityRatio,
rect.width * $.pixelDensityRatio,
rect.height * $.pixelDensityRatio
);
context.restore();
}
// private
_getTextureDataFromTile(tile){
return tile.getCanvasContext().canvas;
}
/**
* Draw data from the rendering canvas onto the output canvas, with clipping,
* cropping and/or debug info as requested.
* @private
* @param {OpenSeadragon.TiledImage} tiledImage - the tiledImage to draw
* @param {Array} tilesToDraw - array of objects containing tiles that were drawn
*/
_applyContext2dPipeline(tiledImage, tilesToDraw, tiledImageIndex){
// composite onto the output canvas, clipping if necessary
this._outputContext.save();
// set composite operation; ignore for first image drawn
this._outputContext.globalCompositeOperation = tiledImageIndex === 0 ? null : tiledImage.compositeOperation || this.viewer.compositeOperation;
if(tiledImage._croppingPolygons || tiledImage._clip){
this._renderToClippingCanvas(tiledImage);
this._outputContext.drawImage(this._clippingCanvas, 0, 0);
} else {
this._outputContext.drawImage(this._renderingCanvas, 0, 0);
}
this._outputContext.restore();
if(tiledImage.debugMode){
let colorIndex = this.viewer.world.getIndexOfItem(tiledImage) % this.debugGridColor.length;
let strokeStyle = this.debugGridColor[colorIndex];
let fillStyle = this.debugGridColor[colorIndex];
this._drawDebugInfo(tilesToDraw, tiledImage, strokeStyle, fillStyle);
}
}
// private
_getTileData(tile, tiledImage, textureInfo, viewMatrix, index, texturePositionArray, textureDataArray, matrixArray, opacityArray){
let texture = textureInfo.texture;
let textureQuad = textureInfo.position;
// set the position of this texture
texturePositionArray.set(textureQuad, index * 12);
// compute offsets that account for tile overlap; needed for calculating the transform matrix appropriately
let overlapFraction = this._calculateOverlapFraction(tile, tiledImage);
let xOffset = tile.positionedBounds.width * overlapFraction.x;
let yOffset = tile.positionedBounds.height * overlapFraction.y;
// x, y, w, h in viewport coords
let x = tile.positionedBounds.x + (tile.x === 0 ? 0 : xOffset);
let y = tile.positionedBounds.y + (tile.y === 0 ? 0 : yOffset);
let right = tile.positionedBounds.x + tile.positionedBounds.width - (tile.isRightMost ? 0 : xOffset);
let bottom = tile.positionedBounds.y + tile.positionedBounds.height - (tile.isBottomMost ? 0 : yOffset);
let w = right - x;
let h = bottom - y;
let matrix = new Mat3([
w, 0, 0,
0, h, 0,
x, y, 1,
]);
if(tile.flipped){
// flip the tile around the center of the unit quad
let t1 = Mat3.makeTranslation(0.5, 0);
let t2 = Mat3.makeTranslation(-0.5, 0);
// update the view matrix to account for this image's rotation
let localMatrix = t1.multiply(Mat3.makeScaling(-1, 1)).multiply(t2);
matrix = matrix.multiply(localMatrix);
}
let overallMatrix = viewMatrix.multiply(matrix);
opacityArray[index] = tile.opacity;// * tiledImage.opacity;
textureDataArray[index] = texture;
matrixArray[index] = overallMatrix.values;
if(this.continuousTileRefresh){
// Upload the image into the texture
// TODO: test if this works appropriately
let tileContext = tile.getCanvasContext();
this._raiseTileDrawingEvent(tiledImage, this._outputContext, tile, tileContext);
this._uploadImageData(tileContext, tile, tiledImage);
}
}
_setupRenderer(){
let gl = this._gl;
if(!gl){
$.console.error('_setupCanvases must be called before _setupRenderer');
}
this._unitQuad = this._makeQuadVertexBuffer(0, 1, 0, 1); // used a few places; create once and store the result
this._makeFirstPassShaderProgram();
this._makeSecondPassShaderProgram();
// set up the texture to render to in the first pass, and which will be used for rendering the second pass
this._renderToTexture = gl.createTexture();
gl.activeTexture(gl.TEXTURE0);
gl.bindTexture(gl.TEXTURE_2D, this._renderToTexture);
gl.texImage2D(gl.TEXTURE_2D, 0, gl.RGBA, this._renderingCanvas.width, this._renderingCanvas.height, 0, gl.RGBA, gl.UNSIGNED_BYTE, null);
gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_MIN_FILTER, gl.LINEAR);
gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_WRAP_S, gl.CLAMP_TO_EDGE);
gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_WRAP_T, gl.CLAMP_TO_EDGE);
// set up the framebuffer for render-to-texture
this._glFrameBuffer = gl.createFramebuffer();
gl.bindFramebuffer(gl.FRAMEBUFFER, this._glFrameBuffer);
gl.framebufferTexture2D(
gl.FRAMEBUFFER,
gl.COLOR_ATTACHMENT0, // attach texture as COLOR_ATTACHMENT0
gl.TEXTURE_2D, // attach a 2D texture
this._renderToTexture, // the texture to attach
0
);
gl.enable(gl.BLEND);
gl.blendFunc(gl.ONE, gl.ONE_MINUS_SRC_ALPHA);
}
_makeFirstPassShaderProgram(){
let numTextures = this._glNumTextures = this._gl.getParameter(this._gl.MAX_TEXTURE_IMAGE_UNITS);
let makeMatrixUniforms = () => {
return [...Array(numTextures).keys()].map(index => `uniform mat3 u_matrix_${index};`).join('\n');
};
let makeConditionals = () => {
return [...Array(numTextures).keys()].map(index => `${index > 0 ? 'else ' : ''}if(int(a_index) == ${index}) { transform_matrix = u_matrix_${index}; }`).join('\n');
};
const vertexShaderProgram = `
attribute vec2 a_output_position;
attribute vec2 a_texture_position;
attribute float a_index;
${makeMatrixUniforms()} // create a uniform mat3 for each potential tile to draw
varying vec2 v_texture_position;
varying float v_image_index;
void main() {
mat3 transform_matrix; // value will be set by the if/elses in makeConditional()
${makeConditionals()}
gl_Position = vec4(transform_matrix * vec3(a_output_position, 1), 1);
v_texture_position = a_texture_position;
v_image_index = a_index;
}
`;
const fragmentShaderProgram = `
precision mediump float;
// our textures
uniform sampler2D u_images[${numTextures}];
// our opacities
uniform float u_opacities[${numTextures}];
// the varyings passed in from the vertex shader.
varying vec2 v_texture_position;
varying float v_image_index;
void main() {
// can't index directly with a variable, need to use a loop iterator hack
for(int i = 0; i < ${numTextures}; ++i){
if(i == int(v_image_index)){
gl_FragColor = texture2D(u_images[i], v_texture_position) * u_opacities[i];
}
}
}
`;
let gl = this._gl;
let program = this.constructor.initShaderProgram(gl, vertexShaderProgram, fragmentShaderProgram);
gl.useProgram(program);
// get locations of attributes and uniforms, and create buffers for each attribute
this._firstPass = {
shaderProgram: program,
aOutputPosition: gl.getAttribLocation(program, 'a_output_position'),
aTexturePosition: gl.getAttribLocation(program, 'a_texture_position'),
aIndex: gl.getAttribLocation(program, 'a_index'),
uTransformMatrices: [...Array(this._glNumTextures).keys()].map(i=>gl.getUniformLocation(program, `u_matrix_${i}`)),
uImages: gl.getUniformLocation(program, 'u_images'),
uOpacities: gl.getUniformLocation(program, 'u_opacities'),
bufferOutputPosition: gl.createBuffer(),
bufferTexturePosition: gl.createBuffer(),
bufferIndex: gl.createBuffer(),
};
gl.uniform1iv(this._firstPass.uImages, [...Array(numTextures).keys()]);
// provide coordinates for the rectangle in output space, i.e. a unit quad for each one.
let outputQuads = new Float32Array(numTextures * 12);
for(let i = 0; i < numTextures; ++i){
outputQuads.set(Float32Array.from(this._unitQuad), i * 12);
}
gl.bindBuffer(gl.ARRAY_BUFFER, this._firstPass.bufferOutputPosition);
gl.bufferData(gl.ARRAY_BUFFER, outputQuads, gl.STATIC_DRAW); // bind data statically here, since it's unchanging
gl.enableVertexAttribArray(this._firstPass.aOutputPosition);
// provide texture coordinates for the rectangle in image (texture) space. Data will be set later.
gl.bindBuffer(gl.ARRAY_BUFFER, this._firstPass.bufferTexturePosition);
gl.enableVertexAttribArray(this._firstPass.aTexturePosition);
// for each vertex, provide an index into the array of textures/matrices to use for the correct tile
gl.bindBuffer(gl.ARRAY_BUFFER, this._firstPass.bufferIndex);
let indices = [...Array(this._glNumTextures).keys()].map(i => Array(6).fill(i)).flat(); // repeat each index 6 times, for the 6 vertices per tile (2 triangles)
gl.bufferData(gl.ARRAY_BUFFER, new Float32Array(indices), gl.STATIC_DRAW); // bind data statically here, since it's unchanging
gl.enableVertexAttribArray(this._firstPass.aIndex);
}
_makeSecondPassShaderProgram(){
const vertexShaderProgram = `
attribute vec2 a_output_position;
attribute vec2 a_texture_position;
uniform mat3 u_matrix;
varying vec2 v_texture_position;
void main() {
gl_Position = vec4(u_matrix * vec3(a_output_position, 1), 1);
v_texture_position = a_texture_position;
}
`;
const fragmentShaderProgram = `
precision mediump float;
// our texture
uniform sampler2D u_image;
// the texCoords passed in from the vertex shader.
varying vec2 v_texture_position;
// the opacity multiplier for the image
uniform float u_opacity_multiplier;
void main() {
gl_FragColor = texture2D(u_image, v_texture_position);
gl_FragColor *= u_opacity_multiplier;
}
`;
let gl = this._gl;
let program = this.constructor.initShaderProgram(gl, vertexShaderProgram, fragmentShaderProgram);
gl.useProgram(program);
// get locations of attributes and uniforms, and create buffers for each attribute
this._secondPass = {
shaderProgram: program,
aOutputPosition: gl.getAttribLocation(program, 'a_output_position'),
aTexturePosition: gl.getAttribLocation(program, 'a_texture_position'),
uMatrix: gl.getUniformLocation(program, 'u_matrix'),
uImage: gl.getUniformLocation(program, 'u_image'),
uOpacityMultiplier: gl.getUniformLocation(program, 'u_opacity_multiplier'),
bufferOutputPosition: gl.createBuffer(),
bufferTexturePosition: gl.createBuffer(),
};
// provide coordinates for the rectangle in output space, i.e. a unit quad for each one.
gl.bindBuffer(gl.ARRAY_BUFFER, this._secondPass.bufferOutputPosition);
gl.bufferData(gl.ARRAY_BUFFER, this._unitQuad, gl.STATIC_DRAW); // bind data statically here since it's unchanging
gl.enableVertexAttribArray(this._secondPass.aOutputPosition);
// provide texture coordinates for the rectangle in image (texture) space.
gl.bindBuffer(gl.ARRAY_BUFFER, this._secondPass.bufferTexturePosition);
gl.bufferData(gl.ARRAY_BUFFER, this._unitQuad, gl.DYNAMIC_DRAW); // bind data statically here since it's unchanging
gl.enableVertexAttribArray(this._secondPass.aTexturePosition);
// set the matrix that transforms the framebuffer to clip space
let matrix = Mat3.makeScaling(2, 2).multiply(Mat3.makeTranslation(-0.5, -0.5));
gl.uniformMatrix3fv(this._secondPass.uMatrix, false, matrix.values);
}
_resizeRenderer(){
let gl = this._gl;
let w = this._renderingCanvas.width;
let h = this._renderingCanvas.height;
gl.viewport(0, 0, w, h);
//release the old texture
gl.deleteTexture(this._renderToTexture);
//create a new texture and set it up
this._renderToTexture = gl.createTexture();
gl.activeTexture(gl.TEXTURE0);
gl.bindTexture(gl.TEXTURE_2D, this._renderToTexture);
gl.texImage2D(gl.TEXTURE_2D, 0, gl.RGBA, w, h, 0, gl.RGBA, gl.UNSIGNED_BYTE, null);
gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_MIN_FILTER, gl.LINEAR);
gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_WRAP_S, gl.CLAMP_TO_EDGE);
gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_WRAP_T, gl.CLAMP_TO_EDGE);
//bind the frame buffer to the new texture
gl.bindFramebuffer(gl.FRAMEBUFFER, this._glFrameBuffer);
gl.framebufferTexture2D(gl.FRAMEBUFFER, gl.COLOR_ATTACHMENT0, gl.TEXTURE_2D, this._renderToTexture, 0);
}
_setupCanvases(){
let _this = this;
this._outputCanvas = this.canvas; //output canvas
this._outputContext = this._outputCanvas.getContext('2d');
this._renderingCanvas = document.createElement('canvas');
this._clippingCanvas = document.createElement('canvas');
this._clippingContext = this._clippingCanvas.getContext('2d');
this._renderingCanvas.width = this._clippingCanvas.width = this._outputCanvas.width;
this._renderingCanvas.height = this._clippingCanvas.height = this._outputCanvas.height;
this._gl = this._renderingCanvas.getContext('webgl');
//make the additional canvas elements mirror size changes to the output canvas
this.viewer.addHandler("resize", function(){
if(_this._outputCanvas !== _this.viewer.drawer.canvas){
_this._outputCanvas.style.width = _this.viewer.drawer.canvas.clientWidth + 'px';
_this._outputCanvas.style.height = _this.viewer.drawer.canvas.clientHeight + 'px';
}
let viewportSize = _this._calculateCanvasSize();
if( _this._outputCanvas.width !== viewportSize.x ||
_this._outputCanvas.height !== viewportSize.y ) {
_this._outputCanvas.width = viewportSize.x;
_this._outputCanvas.height = viewportSize.y;
}
_this._renderingCanvas.style.width = _this._outputCanvas.clientWidth + 'px';
_this._renderingCanvas.style.height = _this._outputCanvas.clientHeight + 'px';
_this._renderingCanvas.width = _this._clippingCanvas.width = _this._outputCanvas.width;
_this._renderingCanvas.height = _this._clippingCanvas.height = _this._outputCanvas.height;
// important - update the size of the rendering viewport!
_this._resizeRenderer();
});
}
_makeQuadVertexBuffer(left, right, top, bottom){
return new Float32Array([
left, bottom,
right, bottom,
left, top,
left, top,
right, bottom,
right, top]);
}
_tileReadyHandler(event){
let tile = event.tile;
let tiledImage = event.tiledImage;
let tileContext = tile.getCanvasContext();
let canvas = tileContext.canvas;
let textureInfo = this._TextureMap.get(canvas);
// if this is a new image for us, create a texture
if(!textureInfo){
let gl = this._gl;
// create a gl Texture for this tile and bind the canvas with the image data
let texture = gl.createTexture();
let position;
let overlap = tiledImage.source.tileOverlap;
if( overlap > 0){
// calculate the normalized position of the rect to actually draw
// discarding overlap.
let overlapFraction = this._calculateOverlapFraction(tile, tiledImage);
let left = tile.x === 0 ? 0 : overlapFraction.x;
let top = tile.y === 0 ? 0 : overlapFraction.y;
let right = tile.isRightMost ? 1 : 1 - overlapFraction.x;
let bottom = tile.isBottomMost ? 1 : 1 - overlapFraction.y;
position = this._makeQuadVertexBuffer(left, right, top, bottom);
} else {
// no overlap: this texture can use the unit quad as it's position data
position = this._unitQuad;
}
let textureInfo = {
texture: texture,
position: position,
};
// add it to our _TextureMap
this._TextureMap.set(canvas, textureInfo);
gl.activeTexture(gl.TEXTURE0);
gl.bindTexture(gl.TEXTURE_2D, texture);
// Set the parameters so we can render any size image.
gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_WRAP_S, gl.CLAMP_TO_EDGE);
gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_WRAP_T, gl.CLAMP_TO_EDGE);
gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_MIN_FILTER, gl.LINEAR);
gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_MAG_FILTER, gl.LINEAR);
// Upload the image into the texture.
this._uploadImageData(tileContext);
}
}
_calculateOverlapFraction(tile, tiledImage){
let overlap = tiledImage.source.tileOverlap;
let nativeWidth = tile.sourceBounds.width; // in pixels
let nativeHeight = tile.sourceBounds.height; // in pixels
let overlapWidth = (tile.x === 0 ? 0 : overlap) + (tile.isRightMost ? 0 : overlap); // in pixels
let overlapHeight = (tile.y === 0 ? 0 : overlap) + (tile.isBottomMost ? 0 : overlap); // in pixels
let widthOverlapFraction = overlap / (nativeWidth + overlapWidth); // as a fraction of image including overlap
let heightOverlapFraction = overlap / (nativeHeight + overlapHeight); // as a fraction of image including overlap
return {
x: widthOverlapFraction,
y: heightOverlapFraction
};
}
_uploadImageData(tileContext){
let gl = this._gl;
let canvas = tileContext.canvas;
try{
if(!canvas){
throw('Tile context does not have a canvas', tileContext);
}
// This depends on gl.TEXTURE_2D being bound to the texture
// associated with this canvas before calling this function
gl.texImage2D(gl.TEXTURE_2D, 0, gl.RGBA, gl.RGBA, gl.UNSIGNED_BYTE, canvas);
} catch (e){
$.console.error('Error uploading image data to WebGL', e);
}
}
_imageUnloadedHandler(event){
let canvas = event.context2D.canvas;
this._cleanupImageData(canvas);
}
_cleanupImageData(tileCanvas){
let textureInfo = this._TextureMap.get(tileCanvas);
//remove from the map
this._TextureMap.delete(tileCanvas);
//release the texture from the GPU
if(textureInfo){
this._gl.deleteTexture(textureInfo.texture);
}
// release the position buffer from the GPU
// TODO: do this!
}
// private
// necessary for clip testing to pass (test uses spyOnce(drawer._setClip))
_setClip(rect){
this._clippingContext.beginPath();
this._clippingContext.rect(rect.x, rect.y, rect.width, rect.height);
this._clippingContext.clip();
}
_renderToClippingCanvas(item){
let _this = this;
this._clippingContext.clearRect(0, 0, this._clippingCanvas.width, this._clippingCanvas.height);
this._clippingContext.save();
if(item._clip){
var box = item.imageToViewportRectangle(item._clip, true);
var rect = this.viewportToDrawerRectangle(box);
this._setClip(rect);
}
if(item._croppingPolygons){
let polygons = item._croppingPolygons.map(function (polygon) {
return polygon.map(function (coord) {
let point = item.imageToViewportCoordinates(coord.x, coord.y, true)
.rotate(_this.viewer.viewport.getRotation(true), _this.viewer.viewport.getCenter(true));
let clipPoint = _this._viewportCoordToDrawerCoord(point);
return clipPoint;
});
});
this._clippingContext.beginPath();
polygons.forEach(function (polygon) {
polygon.forEach(function (coord, i) {
_this._clippingContext[i === 0 ? 'moveTo' : 'lineTo'](coord.x, coord.y);
});
});
this._clippingContext.clip();
}
this._clippingContext.drawImage(this._renderingCanvas, 0, 0);
this._clippingContext.restore();
}
// private
_offsetForRotation(options) {
var point = options.point ?
options.point.times($.pixelDensityRatio) :
new $.Point(this._outputCanvas.width / 2, this._outputCanvas.height / 2);
var context = this._outputContext;
context.save();
context.translate(point.x, point.y);
if(this.viewport.flipped){
context.rotate(Math.PI / 180 * -options.degrees);
context.scale(-1, 1);
} else{
context.rotate(Math.PI / 180 * options.degrees);
}
context.translate(-point.x, -point.y);
}
/**
* @private
* @inner
* This function converts the given point from to the drawer coordinate by
* multiplying it with the pixel density.
* This function does not take rotation into account, thus assuming provided
* point is at 0 degree.
* @param {OpenSeadragon.Point} point - the pixel point to convert
* @returns {OpenSeadragon.Point} Point in drawer coordinate system.
*/
_viewportCoordToDrawerCoord(point) {
var vpPoint = this.viewport.pixelFromPointNoRotate(point, true);
return new $.Point(
vpPoint.x * $.pixelDensityRatio,
vpPoint.y * $.pixelDensityRatio
);
}
// private
_drawDebugInfo( tilesToDraw, tiledImage, stroke, fill ) {
for ( var i = tilesToDraw.length - 1; i >= 0; i-- ) {
var tile = tilesToDraw[ i ].tile;
try {
this._drawDebugInfoOnTile(tile, tilesToDraw.length, i, tiledImage, stroke, fill);
} catch(e) {
$.console.error(e);
}
}
}
// private
_drawDebugInfoOnTile(tile, count, i, tiledImage, stroke, fill) {
var context = this._outputContext;
context.save();
context.lineWidth = 2 * $.pixelDensityRatio;
context.font = 'small-caps bold ' + (13 * $.pixelDensityRatio) + 'px arial';
context.strokeStyle = stroke;
context.fillStyle = fill;
if (this.viewport.getRotation(true) % 360 !== 0 ) {
this._offsetForRotation({degrees: this.viewport.getRotation(true)});
}
if (tiledImage.getRotation(true) % 360 !== 0) {
this._offsetForRotation({
degrees: tiledImage.getRotation(true),
point: tiledImage.viewport.pixelFromPointNoRotate(
tiledImage._getRotationPoint(true), true)
});
}
if (tiledImage.viewport.getRotation(true) % 360 === 0 &&
tiledImage.getRotation(true) % 360 === 0) {
if(tiledImage._drawer.viewer.viewport.getFlip()) {
tiledImage._drawer._flip();
}
}
context.strokeRect(
tile.position.x * $.pixelDensityRatio,
tile.position.y * $.pixelDensityRatio,
tile.size.x * $.pixelDensityRatio,
tile.size.y * $.pixelDensityRatio
);
var tileCenterX = (tile.position.x + (tile.size.x / 2)) * $.pixelDensityRatio;
var tileCenterY = (tile.position.y + (tile.size.y / 2)) * $.pixelDensityRatio;
// Rotate the text the right way around.
context.translate( tileCenterX, tileCenterY );
context.rotate( Math.PI / 180 * -this.viewport.getRotation(true) );
context.translate( -tileCenterX, -tileCenterY );
if( tile.x === 0 && tile.y === 0 ){
context.fillText(
"Zoom: " + this.viewport.getZoom(),
tile.position.x * $.pixelDensityRatio,
(tile.position.y - 30) * $.pixelDensityRatio
);
context.fillText(
"Pan: " + this.viewport.getBounds().toString(),
tile.position.x * $.pixelDensityRatio,
(tile.position.y - 20) * $.pixelDensityRatio
);
}
context.fillText(
"Level: " + tile.level,
(tile.position.x + 10) * $.pixelDensityRatio,
(tile.position.y + 20) * $.pixelDensityRatio
);
context.fillText(
"Column: " + tile.x,
(tile.position.x + 10) * $.pixelDensityRatio,
(tile.position.y + 30) * $.pixelDensityRatio
);
context.fillText(
"Row: " + tile.y,
(tile.position.x + 10) * $.pixelDensityRatio,
(tile.position.y + 40) * $.pixelDensityRatio
);
context.fillText(
"Order: " + i + " of " + count,
(tile.position.x + 10) * $.pixelDensityRatio,
(tile.position.y + 50) * $.pixelDensityRatio
);
context.fillText(
"Size: " + tile.size.toString(),
(tile.position.x + 10) * $.pixelDensityRatio,
(tile.position.y + 60) * $.pixelDensityRatio
);
context.fillText(
"Position: " + tile.position.toString(),
(tile.position.x + 10) * $.pixelDensityRatio,
(tile.position.y + 70) * $.pixelDensityRatio
);
if (this.viewport.getRotation(true) % 360 !== 0 ) {
this._restoreRotationChanges();
}
if (tiledImage.getRotation(true) % 360 !== 0) {
this._restoreRotationChanges();
}
if (tiledImage.viewport.getRotation(true) % 360 === 0 &&
tiledImage.getRotation(true) % 360 === 0) {
if(tiledImage._drawer.viewer.viewport.getFlip()) {
tiledImage._drawer._flip();
}
}
context.restore();
}
// private
_restoreRotationChanges() {
var context = this._outputContext;
context.restore();
}
// modified from https://developer.mozilla.org/en-US/docs/Web/API/WebGL_API/Tutorial/Adding_2D_content_to_a_WebGL_context
static initShaderProgram(gl, vsSource, fsSource) {
const vertexShader = loadShader(gl, gl.VERTEX_SHADER, vsSource);
const fragmentShader = loadShader(gl, gl.FRAGMENT_SHADER, fsSource);
// Create the shader program
const shaderProgram = gl.createProgram();
gl.attachShader(shaderProgram, vertexShader);
gl.attachShader(shaderProgram, fragmentShader);
gl.linkProgram(shaderProgram);
// If creating the shader program failed, alert
if (!gl.getProgramParameter(shaderProgram, gl.LINK_STATUS)) {
alert(
`Unable to initialize the shader program: ${gl.getProgramInfoLog(
shaderProgram
)}`
);
return null;
}
return shaderProgram;
function loadShader(gl, type, source) {
const shader = gl.createShader(type);
// Send the source to the shader object
gl.shaderSource(shader, source);
// Compile the shader program
gl.compileShader(shader);
// See if it compiled successfully
if (!gl.getShaderParameter(shader, gl.COMPILE_STATUS)) {
alert(
`An error occurred compiling the shaders: ${gl.getShaderInfoLog(shader)}`
);
gl.deleteShader(shader);
return null;
}
return shader;
}
}
};
}( OpenSeadragon ));