mirror of
https://github.com/zen-browser/pdf.js.git
synced 2025-07-10 02:05:37 +02:00
59b5e14301
This patch is one (small) step on the way to reduce the general dependency on a global `PDFJS` object, for PDF.js version `2.0`.
464 lines
17 KiB
JavaScript
464 lines
17 KiB
JavaScript
/* Copyright 2014 Mozilla Foundation
|
|
*
|
|
* Licensed under the Apache License, Version 2.0 (the "License");
|
|
* you may not use this file except in compliance with the License.
|
|
* You may obtain a copy of the License at
|
|
*
|
|
* http://www.apache.org/licenses/LICENSE-2.0
|
|
*
|
|
* Unless required by applicable law or agreed to in writing, software
|
|
* distributed under the License is distributed on an "AS IS" BASIS,
|
|
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
|
|
* See the License for the specific language governing permissions and
|
|
* limitations under the License.
|
|
*/
|
|
/* eslint-disable no-multi-str */
|
|
|
|
import { shadow } from '../shared/util';
|
|
|
|
class WebGLContext {
|
|
constructor({ enable = false, }) {
|
|
this._enabled = enable === true;
|
|
}
|
|
|
|
get isEnabled() {
|
|
let enabled = this._enabled;
|
|
if (enabled) {
|
|
enabled = WebGLUtils.tryInitGL();
|
|
}
|
|
return shadow(this, 'isEnabled', enabled);
|
|
}
|
|
|
|
composeSMask({ layer, mask, properties, }) {
|
|
return WebGLUtils.composeSMask(layer, mask, properties);
|
|
}
|
|
|
|
drawFigures({ width, height, backgroundColor, figures, context, }) {
|
|
return WebGLUtils.drawFigures(width, height, backgroundColor, figures,
|
|
context);
|
|
}
|
|
|
|
clear() {
|
|
WebGLUtils.cleanup();
|
|
}
|
|
}
|
|
|
|
var WebGLUtils = (function WebGLUtilsClosure() {
|
|
function loadShader(gl, code, shaderType) {
|
|
var shader = gl.createShader(shaderType);
|
|
gl.shaderSource(shader, code);
|
|
gl.compileShader(shader);
|
|
var compiled = gl.getShaderParameter(shader, gl.COMPILE_STATUS);
|
|
if (!compiled) {
|
|
var errorMsg = gl.getShaderInfoLog(shader);
|
|
throw new Error('Error during shader compilation: ' + errorMsg);
|
|
}
|
|
return shader;
|
|
}
|
|
function createVertexShader(gl, code) {
|
|
return loadShader(gl, code, gl.VERTEX_SHADER);
|
|
}
|
|
function createFragmentShader(gl, code) {
|
|
return loadShader(gl, code, gl.FRAGMENT_SHADER);
|
|
}
|
|
function createProgram(gl, shaders) {
|
|
var program = gl.createProgram();
|
|
for (var i = 0, ii = shaders.length; i < ii; ++i) {
|
|
gl.attachShader(program, shaders[i]);
|
|
}
|
|
gl.linkProgram(program);
|
|
var linked = gl.getProgramParameter(program, gl.LINK_STATUS);
|
|
if (!linked) {
|
|
var errorMsg = gl.getProgramInfoLog(program);
|
|
throw new Error('Error during program linking: ' + errorMsg);
|
|
}
|
|
return program;
|
|
}
|
|
function createTexture(gl, image, textureId) {
|
|
gl.activeTexture(textureId);
|
|
var texture = gl.createTexture();
|
|
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.NEAREST);
|
|
gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_MAG_FILTER, gl.NEAREST);
|
|
|
|
// Upload the image into the texture.
|
|
gl.texImage2D(gl.TEXTURE_2D, 0, gl.RGBA, gl.RGBA, gl.UNSIGNED_BYTE, image);
|
|
return texture;
|
|
}
|
|
|
|
var currentGL, currentCanvas;
|
|
function generateGL() {
|
|
if (currentGL) {
|
|
return;
|
|
}
|
|
|
|
// The temporary canvas is used in the WebGL context.
|
|
currentCanvas = document.createElement('canvas');
|
|
currentGL = currentCanvas.getContext('webgl',
|
|
{ premultipliedalpha: false, });
|
|
}
|
|
|
|
var smaskVertexShaderCode = '\
|
|
attribute vec2 a_position; \
|
|
attribute vec2 a_texCoord; \
|
|
\
|
|
uniform vec2 u_resolution; \
|
|
\
|
|
varying vec2 v_texCoord; \
|
|
\
|
|
void main() { \
|
|
vec2 clipSpace = (a_position / u_resolution) * 2.0 - 1.0; \
|
|
gl_Position = vec4(clipSpace * vec2(1, -1), 0, 1); \
|
|
\
|
|
v_texCoord = a_texCoord; \
|
|
} ';
|
|
|
|
var smaskFragmentShaderCode = '\
|
|
precision mediump float; \
|
|
\
|
|
uniform vec4 u_backdrop; \
|
|
uniform int u_subtype; \
|
|
uniform sampler2D u_image; \
|
|
uniform sampler2D u_mask; \
|
|
\
|
|
varying vec2 v_texCoord; \
|
|
\
|
|
void main() { \
|
|
vec4 imageColor = texture2D(u_image, v_texCoord); \
|
|
vec4 maskColor = texture2D(u_mask, v_texCoord); \
|
|
if (u_backdrop.a > 0.0) { \
|
|
maskColor.rgb = maskColor.rgb * maskColor.a + \
|
|
u_backdrop.rgb * (1.0 - maskColor.a); \
|
|
} \
|
|
float lum; \
|
|
if (u_subtype == 0) { \
|
|
lum = maskColor.a; \
|
|
} else { \
|
|
lum = maskColor.r * 0.3 + maskColor.g * 0.59 + \
|
|
maskColor.b * 0.11; \
|
|
} \
|
|
imageColor.a *= lum; \
|
|
imageColor.rgb *= imageColor.a; \
|
|
gl_FragColor = imageColor; \
|
|
} ';
|
|
|
|
var smaskCache = null;
|
|
|
|
function initSmaskGL() {
|
|
var canvas, gl;
|
|
|
|
generateGL();
|
|
canvas = currentCanvas;
|
|
currentCanvas = null;
|
|
gl = currentGL;
|
|
currentGL = null;
|
|
|
|
// setup a GLSL program
|
|
var vertexShader = createVertexShader(gl, smaskVertexShaderCode);
|
|
var fragmentShader = createFragmentShader(gl, smaskFragmentShaderCode);
|
|
var program = createProgram(gl, [vertexShader, fragmentShader]);
|
|
gl.useProgram(program);
|
|
|
|
var cache = {};
|
|
cache.gl = gl;
|
|
cache.canvas = canvas;
|
|
cache.resolutionLocation = gl.getUniformLocation(program, 'u_resolution');
|
|
cache.positionLocation = gl.getAttribLocation(program, 'a_position');
|
|
cache.backdropLocation = gl.getUniformLocation(program, 'u_backdrop');
|
|
cache.subtypeLocation = gl.getUniformLocation(program, 'u_subtype');
|
|
|
|
var texCoordLocation = gl.getAttribLocation(program, 'a_texCoord');
|
|
var texLayerLocation = gl.getUniformLocation(program, 'u_image');
|
|
var texMaskLocation = gl.getUniformLocation(program, 'u_mask');
|
|
|
|
// provide texture coordinates for the rectangle.
|
|
var texCoordBuffer = gl.createBuffer();
|
|
gl.bindBuffer(gl.ARRAY_BUFFER, texCoordBuffer);
|
|
gl.bufferData(gl.ARRAY_BUFFER, new Float32Array([
|
|
0.0, 0.0,
|
|
1.0, 0.0,
|
|
0.0, 1.0,
|
|
0.0, 1.0,
|
|
1.0, 0.0,
|
|
1.0, 1.0]), gl.STATIC_DRAW);
|
|
gl.enableVertexAttribArray(texCoordLocation);
|
|
gl.vertexAttribPointer(texCoordLocation, 2, gl.FLOAT, false, 0, 0);
|
|
|
|
gl.uniform1i(texLayerLocation, 0);
|
|
gl.uniform1i(texMaskLocation, 1);
|
|
|
|
smaskCache = cache;
|
|
}
|
|
|
|
function composeSMask(layer, mask, properties) {
|
|
var width = layer.width, height = layer.height;
|
|
|
|
if (!smaskCache) {
|
|
initSmaskGL();
|
|
}
|
|
var cache = smaskCache, canvas = cache.canvas, gl = cache.gl;
|
|
canvas.width = width;
|
|
canvas.height = height;
|
|
gl.viewport(0, 0, gl.drawingBufferWidth, gl.drawingBufferHeight);
|
|
gl.uniform2f(cache.resolutionLocation, width, height);
|
|
|
|
if (properties.backdrop) {
|
|
gl.uniform4f(cache.resolutionLocation, properties.backdrop[0],
|
|
properties.backdrop[1], properties.backdrop[2], 1);
|
|
} else {
|
|
gl.uniform4f(cache.resolutionLocation, 0, 0, 0, 0);
|
|
}
|
|
gl.uniform1i(cache.subtypeLocation,
|
|
properties.subtype === 'Luminosity' ? 1 : 0);
|
|
|
|
// Create a textures
|
|
var texture = createTexture(gl, layer, gl.TEXTURE0);
|
|
var maskTexture = createTexture(gl, mask, gl.TEXTURE1);
|
|
|
|
|
|
// Create a buffer and put a single clipspace rectangle in
|
|
// it (2 triangles)
|
|
var buffer = gl.createBuffer();
|
|
gl.bindBuffer(gl.ARRAY_BUFFER, buffer);
|
|
gl.bufferData(gl.ARRAY_BUFFER, new Float32Array([
|
|
0, 0,
|
|
width, 0,
|
|
0, height,
|
|
0, height,
|
|
width, 0,
|
|
width, height]), gl.STATIC_DRAW);
|
|
gl.enableVertexAttribArray(cache.positionLocation);
|
|
gl.vertexAttribPointer(cache.positionLocation, 2, gl.FLOAT, false, 0, 0);
|
|
|
|
// draw
|
|
gl.clearColor(0, 0, 0, 0);
|
|
gl.enable(gl.BLEND);
|
|
gl.blendFunc(gl.ONE, gl.ONE_MINUS_SRC_ALPHA);
|
|
gl.clear(gl.COLOR_BUFFER_BIT);
|
|
|
|
gl.drawArrays(gl.TRIANGLES, 0, 6);
|
|
|
|
gl.flush();
|
|
|
|
gl.deleteTexture(texture);
|
|
gl.deleteTexture(maskTexture);
|
|
gl.deleteBuffer(buffer);
|
|
|
|
return canvas;
|
|
}
|
|
|
|
var figuresVertexShaderCode = '\
|
|
attribute vec2 a_position; \
|
|
attribute vec3 a_color; \
|
|
\
|
|
uniform vec2 u_resolution; \
|
|
uniform vec2 u_scale; \
|
|
uniform vec2 u_offset; \
|
|
\
|
|
varying vec4 v_color; \
|
|
\
|
|
void main() { \
|
|
vec2 position = (a_position + u_offset) * u_scale; \
|
|
vec2 clipSpace = (position / u_resolution) * 2.0 - 1.0; \
|
|
gl_Position = vec4(clipSpace * vec2(1, -1), 0, 1); \
|
|
\
|
|
v_color = vec4(a_color / 255.0, 1.0); \
|
|
} ';
|
|
|
|
var figuresFragmentShaderCode = '\
|
|
precision mediump float; \
|
|
\
|
|
varying vec4 v_color; \
|
|
\
|
|
void main() { \
|
|
gl_FragColor = v_color; \
|
|
} ';
|
|
|
|
var figuresCache = null;
|
|
|
|
function initFiguresGL() {
|
|
var canvas, gl;
|
|
|
|
generateGL();
|
|
canvas = currentCanvas;
|
|
currentCanvas = null;
|
|
gl = currentGL;
|
|
currentGL = null;
|
|
|
|
// setup a GLSL program
|
|
var vertexShader = createVertexShader(gl, figuresVertexShaderCode);
|
|
var fragmentShader = createFragmentShader(gl, figuresFragmentShaderCode);
|
|
var program = createProgram(gl, [vertexShader, fragmentShader]);
|
|
gl.useProgram(program);
|
|
|
|
var cache = {};
|
|
cache.gl = gl;
|
|
cache.canvas = canvas;
|
|
cache.resolutionLocation = gl.getUniformLocation(program, 'u_resolution');
|
|
cache.scaleLocation = gl.getUniformLocation(program, 'u_scale');
|
|
cache.offsetLocation = gl.getUniformLocation(program, 'u_offset');
|
|
cache.positionLocation = gl.getAttribLocation(program, 'a_position');
|
|
cache.colorLocation = gl.getAttribLocation(program, 'a_color');
|
|
|
|
figuresCache = cache;
|
|
}
|
|
|
|
function drawFigures(width, height, backgroundColor, figures, context) {
|
|
if (!figuresCache) {
|
|
initFiguresGL();
|
|
}
|
|
var cache = figuresCache, canvas = cache.canvas, gl = cache.gl;
|
|
|
|
canvas.width = width;
|
|
canvas.height = height;
|
|
gl.viewport(0, 0, gl.drawingBufferWidth, gl.drawingBufferHeight);
|
|
gl.uniform2f(cache.resolutionLocation, width, height);
|
|
|
|
// count triangle points
|
|
var count = 0;
|
|
var i, ii, rows;
|
|
for (i = 0, ii = figures.length; i < ii; i++) {
|
|
switch (figures[i].type) {
|
|
case 'lattice':
|
|
rows = (figures[i].coords.length / figures[i].verticesPerRow) | 0;
|
|
count += (rows - 1) * (figures[i].verticesPerRow - 1) * 6;
|
|
break;
|
|
case 'triangles':
|
|
count += figures[i].coords.length;
|
|
break;
|
|
}
|
|
}
|
|
// transfer data
|
|
var coords = new Float32Array(count * 2);
|
|
var colors = new Uint8Array(count * 3);
|
|
var coordsMap = context.coords, colorsMap = context.colors;
|
|
var pIndex = 0, cIndex = 0;
|
|
for (i = 0, ii = figures.length; i < ii; i++) {
|
|
var figure = figures[i], ps = figure.coords, cs = figure.colors;
|
|
switch (figure.type) {
|
|
case 'lattice':
|
|
var cols = figure.verticesPerRow;
|
|
rows = (ps.length / cols) | 0;
|
|
for (var row = 1; row < rows; row++) {
|
|
var offset = row * cols + 1;
|
|
for (var col = 1; col < cols; col++, offset++) {
|
|
coords[pIndex] = coordsMap[ps[offset - cols - 1]];
|
|
coords[pIndex + 1] = coordsMap[ps[offset - cols - 1] + 1];
|
|
coords[pIndex + 2] = coordsMap[ps[offset - cols]];
|
|
coords[pIndex + 3] = coordsMap[ps[offset - cols] + 1];
|
|
coords[pIndex + 4] = coordsMap[ps[offset - 1]];
|
|
coords[pIndex + 5] = coordsMap[ps[offset - 1] + 1];
|
|
colors[cIndex] = colorsMap[cs[offset - cols - 1]];
|
|
colors[cIndex + 1] = colorsMap[cs[offset - cols - 1] + 1];
|
|
colors[cIndex + 2] = colorsMap[cs[offset - cols - 1] + 2];
|
|
colors[cIndex + 3] = colorsMap[cs[offset - cols]];
|
|
colors[cIndex + 4] = colorsMap[cs[offset - cols] + 1];
|
|
colors[cIndex + 5] = colorsMap[cs[offset - cols] + 2];
|
|
colors[cIndex + 6] = colorsMap[cs[offset - 1]];
|
|
colors[cIndex + 7] = colorsMap[cs[offset - 1] + 1];
|
|
colors[cIndex + 8] = colorsMap[cs[offset - 1] + 2];
|
|
|
|
coords[pIndex + 6] = coords[pIndex + 2];
|
|
coords[pIndex + 7] = coords[pIndex + 3];
|
|
coords[pIndex + 8] = coords[pIndex + 4];
|
|
coords[pIndex + 9] = coords[pIndex + 5];
|
|
coords[pIndex + 10] = coordsMap[ps[offset]];
|
|
coords[pIndex + 11] = coordsMap[ps[offset] + 1];
|
|
colors[cIndex + 9] = colors[cIndex + 3];
|
|
colors[cIndex + 10] = colors[cIndex + 4];
|
|
colors[cIndex + 11] = colors[cIndex + 5];
|
|
colors[cIndex + 12] = colors[cIndex + 6];
|
|
colors[cIndex + 13] = colors[cIndex + 7];
|
|
colors[cIndex + 14] = colors[cIndex + 8];
|
|
colors[cIndex + 15] = colorsMap[cs[offset]];
|
|
colors[cIndex + 16] = colorsMap[cs[offset] + 1];
|
|
colors[cIndex + 17] = colorsMap[cs[offset] + 2];
|
|
pIndex += 12;
|
|
cIndex += 18;
|
|
}
|
|
}
|
|
break;
|
|
case 'triangles':
|
|
for (var j = 0, jj = ps.length; j < jj; j++) {
|
|
coords[pIndex] = coordsMap[ps[j]];
|
|
coords[pIndex + 1] = coordsMap[ps[j] + 1];
|
|
colors[cIndex] = colorsMap[cs[j]];
|
|
colors[cIndex + 1] = colorsMap[cs[j] + 1];
|
|
colors[cIndex + 2] = colorsMap[cs[j] + 2];
|
|
pIndex += 2;
|
|
cIndex += 3;
|
|
}
|
|
break;
|
|
}
|
|
}
|
|
|
|
// draw
|
|
if (backgroundColor) {
|
|
gl.clearColor(backgroundColor[0] / 255, backgroundColor[1] / 255,
|
|
backgroundColor[2] / 255, 1.0);
|
|
} else {
|
|
gl.clearColor(0, 0, 0, 0);
|
|
}
|
|
gl.clear(gl.COLOR_BUFFER_BIT);
|
|
|
|
var coordsBuffer = gl.createBuffer();
|
|
gl.bindBuffer(gl.ARRAY_BUFFER, coordsBuffer);
|
|
gl.bufferData(gl.ARRAY_BUFFER, coords, gl.STATIC_DRAW);
|
|
gl.enableVertexAttribArray(cache.positionLocation);
|
|
gl.vertexAttribPointer(cache.positionLocation, 2, gl.FLOAT, false, 0, 0);
|
|
|
|
var colorsBuffer = gl.createBuffer();
|
|
gl.bindBuffer(gl.ARRAY_BUFFER, colorsBuffer);
|
|
gl.bufferData(gl.ARRAY_BUFFER, colors, gl.STATIC_DRAW);
|
|
gl.enableVertexAttribArray(cache.colorLocation);
|
|
gl.vertexAttribPointer(cache.colorLocation, 3, gl.UNSIGNED_BYTE, false,
|
|
0, 0);
|
|
|
|
gl.uniform2f(cache.scaleLocation, context.scaleX, context.scaleY);
|
|
gl.uniform2f(cache.offsetLocation, context.offsetX, context.offsetY);
|
|
|
|
gl.drawArrays(gl.TRIANGLES, 0, count);
|
|
|
|
gl.flush();
|
|
|
|
gl.deleteBuffer(coordsBuffer);
|
|
gl.deleteBuffer(colorsBuffer);
|
|
|
|
return canvas;
|
|
}
|
|
|
|
return {
|
|
tryInitGL() {
|
|
try {
|
|
generateGL();
|
|
return !!currentGL;
|
|
} catch (ex) { }
|
|
return false;
|
|
},
|
|
|
|
composeSMask,
|
|
|
|
drawFigures,
|
|
|
|
cleanup() {
|
|
if (smaskCache && smaskCache.canvas) {
|
|
smaskCache.canvas.width = 0;
|
|
smaskCache.canvas.height = 0;
|
|
}
|
|
if (figuresCache && figuresCache.canvas) {
|
|
figuresCache.canvas.width = 0;
|
|
figuresCache.canvas.height = 0;
|
|
}
|
|
smaskCache = null;
|
|
figuresCache = null;
|
|
},
|
|
};
|
|
})();
|
|
|
|
export {
|
|
WebGLContext,
|
|
};
|