tenfourfox/devtools/server/actors/webgl.js
Cameron Kaiser c9b2922b70 hello FPR
2017-04-19 00:56:45 -07:00

1405 lines
43 KiB
JavaScript

/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
"use strict";
const {Cc, Ci, Cu, Cr} = require("chrome");
const events = require("sdk/event/core");
const promise = require("promise");
const protocol = require("devtools/server/protocol");
const { ContentObserver } = require("devtools/shared/content-observer");
const { on, once, off, emit } = events;
const { method, Arg, Option, RetVal } = protocol;
const WEBGL_CONTEXT_NAMES = ["webgl", "experimental-webgl", "moz-webgl"];
// These traits are bit masks. Make sure they're powers of 2.
const PROGRAM_DEFAULT_TRAITS = 0;
const PROGRAM_BLACKBOX_TRAIT = 1;
const PROGRAM_HIGHLIGHT_TRAIT = 2;
/**
* A WebGL Shader contributing to building a WebGL Program.
* You can either retrieve, or compile the source of a shader, which will
* automatically inflict the necessary changes to the WebGL state.
*/
var ShaderActor = protocol.ActorClass({
typeName: "gl-shader",
/**
* Create the shader actor.
*
* @param DebuggerServerConnection conn
* The server connection.
* @param WebGLProgram program
* The WebGL program being linked.
* @param WebGLShader shader
* The cooresponding vertex or fragment shader.
* @param WebGLProxy proxy
* The proxy methods for the WebGL context owning this shader.
*/
initialize: function(conn, program, shader, proxy) {
protocol.Actor.prototype.initialize.call(this, conn);
this.program = program;
this.shader = shader;
this.text = proxy.getShaderSource(shader);
this.linkedProxy = proxy;
},
/**
* Gets the source code for this shader.
*/
getText: method(function() {
return this.text;
}, {
response: { text: RetVal("string") }
}),
/**
* Sets and compiles new source code for this shader.
*/
compile: method(function(text) {
// Get the shader and corresponding program to change via the WebGL proxy.
let { linkedProxy: proxy, shader, program } = this;
// Get the new shader source to inject.
let oldText = this.text;
let newText = text;
// Overwrite the shader's source.
let error = proxy.compileShader(program, shader, this.text = newText);
// If something went wrong, revert to the previous shader.
if (error.compile || error.link) {
proxy.compileShader(program, shader, this.text = oldText);
return error;
}
return undefined;
}, {
request: { text: Arg(0, "string") },
response: { error: RetVal("nullable:json") }
})
});
/**
* The corresponding Front object for the ShaderActor.
*/
var ShaderFront = protocol.FrontClass(ShaderActor, {
initialize: function(client, form) {
protocol.Front.prototype.initialize.call(this, client, form);
}
});
/**
* A WebGL program is composed (at the moment, analogue to OpenGL ES 2.0)
* of two shaders: a vertex shader and a fragment shader.
*/
var ProgramActor = protocol.ActorClass({
typeName: "gl-program",
/**
* Create the program actor.
*
* @param DebuggerServerConnection conn
* The server connection.
* @param WebGLProgram program
* The WebGL program being linked.
* @param WebGLShader[] shaders
* The WebGL program's cooresponding vertex and fragment shaders.
* @param WebGLCache cache
* The state storage for the WebGL context owning this program.
* @param WebGLProxy proxy
* The proxy methods for the WebGL context owning this program.
*/
initialize: function(conn, [program, shaders, cache, proxy]) {
protocol.Actor.prototype.initialize.call(this, conn);
this._shaderActorsCache = { vertex: null, fragment: null };
this.program = program;
this.shaders = shaders;
this.linkedCache = cache;
this.linkedProxy = proxy;
},
get ownerWindow() {
return this.linkedCache.ownerWindow;
},
get ownerContext() {
return this.linkedCache.ownerContext;
},
/**
* Gets the vertex shader linked to this program. This method guarantees
* a single actor instance per shader.
*/
getVertexShader: method(function() {
return this._getShaderActor("vertex");
}, {
response: { shader: RetVal("gl-shader") }
}),
/**
* Gets the fragment shader linked to this program. This method guarantees
* a single actor instance per shader.
*/
getFragmentShader: method(function() {
return this._getShaderActor("fragment");
}, {
response: { shader: RetVal("gl-shader") }
}),
/**
* Highlights any geometry rendered using this program.
*/
highlight: method(function(tint) {
this.linkedProxy.highlightTint = tint;
this.linkedCache.setProgramTrait(this.program, PROGRAM_HIGHLIGHT_TRAIT);
}, {
request: { tint: Arg(0, "array:number") },
oneway: true
}),
/**
* Allows geometry to be rendered normally using this program.
*/
unhighlight: method(function() {
this.linkedCache.unsetProgramTrait(this.program, PROGRAM_HIGHLIGHT_TRAIT);
}, {
oneway: true
}),
/**
* Prevents any geometry from being rendered using this program.
*/
blackbox: method(function() {
this.linkedCache.setProgramTrait(this.program, PROGRAM_BLACKBOX_TRAIT);
}, {
oneway: true
}),
/**
* Allows geometry to be rendered using this program.
*/
unblackbox: method(function() {
this.linkedCache.unsetProgramTrait(this.program, PROGRAM_BLACKBOX_TRAIT);
}, {
oneway: true
}),
/**
* Returns a cached ShaderActor instance based on the required shader type.
*
* @param string type
* Either "vertex" or "fragment".
* @return ShaderActor
* The respective shader actor instance.
*/
_getShaderActor: function(type) {
if (this._shaderActorsCache[type]) {
return this._shaderActorsCache[type];
}
let proxy = this.linkedProxy;
let shader = proxy.getShaderOfType(this.shaders, type);
let shaderActor = new ShaderActor(this.conn, this.program, shader, proxy);
return this._shaderActorsCache[type] = shaderActor;
}
});
/**
* The corresponding Front object for the ProgramActor.
*/
var ProgramFront = protocol.FrontClass(ProgramActor, {
initialize: function(client, form) {
protocol.Front.prototype.initialize.call(this, client, form);
}
});
/**
* The WebGL Actor handles simple interaction with a WebGL context via a few
* high-level methods. After instantiating this actor, you'll need to set it
* up by calling setup().
*/
var WebGLActor = exports.WebGLActor = protocol.ActorClass({
typeName: "webgl",
initialize: function(conn, tabActor) {
protocol.Actor.prototype.initialize.call(this, conn);
this.tabActor = tabActor;
this._onGlobalCreated = this._onGlobalCreated.bind(this);
this._onGlobalDestroyed = this._onGlobalDestroyed.bind(this);
this._onProgramLinked = this._onProgramLinked.bind(this);
},
destroy: function(conn) {
protocol.Actor.prototype.destroy.call(this, conn);
this.finalize();
},
/**
* Starts waiting for the current tab actor's document global to be
* created, in order to instrument the Canvas context and become
* aware of everything the content does WebGL-wise.
*
* See ContentObserver and WebGLInstrumenter for more details.
*/
setup: method(function({ reload }) {
if (this._initialized) {
return;
}
this._initialized = true;
this._programActorsCache = [];
this._webglObserver = new WebGLObserver();
on(this.tabActor, "window-ready", this._onGlobalCreated);
on(this.tabActor, "window-destroyed", this._onGlobalDestroyed);
on(this._webglObserver, "program-linked", this._onProgramLinked);
if (reload) {
this.tabActor.window.location.reload();
}
}, {
request: { reload: Option(0, "boolean") },
oneway: true
}),
/**
* Stops listening for document global changes and puts this actor
* to hibernation. This method is called automatically just before the
* actor is destroyed.
*/
finalize: method(function() {
if (!this._initialized) {
return;
}
this._initialized = false;
off(this.tabActor, "window-ready", this._onGlobalCreated);
off(this.tabActor, "window-destroyed", this._onGlobalDestroyed);
off(this._webglObserver, "program-linked", this._onProgramLinked);
this._programActorsCache = null;
this._contentObserver = null;
this._webglObserver = null;
}, {
oneway: true
}),
/**
* Gets an array of cached program actors for the current tab actor's window.
* This is useful for dealing with bfcache, when no new programs are linked.
*/
getPrograms: method(function() {
let id = ContentObserver.GetInnerWindowID(this.tabActor.window);
return this._programActorsCache.filter(e => e.ownerWindow == id);
}, {
response: { programs: RetVal("array:gl-program") }
}),
/**
* Waits for one frame via `requestAnimationFrame` on the tab actor's window.
* Used in tests.
*/
waitForFrame: method(function () {
let deferred = promise.defer();
this.tabActor.window.requestAnimationFrame(deferred.resolve);
return deferred.promise;
}, {
response: { success: RetVal("nullable:json") }
}),
/**
* Gets a pixel's RGBA value from a context specified by selector
* and the coordinates of the pixel in question.
* Currently only used in tests.
*
* @param string selector
* A string selector to select the canvas in question from the DOM.
* @param Object position
* An object with an `x` and `y` property indicating coordinates of the pixel being inspected.
* @return Object
* An object containing `r`, `g`, `b`, and `a` properties of the pixel.
*/
getPixel: method(function ({ selector, position }) {
let { x, y } = position;
let canvas = this.tabActor.window.document.querySelector(selector);
let context = XPCNativeWrapper.unwrap(canvas.getContext("webgl"));
let { proxy } = this._webglObserver.for(context);
let height = canvas.height;
let buffer = new this.tabActor.window.Uint8Array(4);
buffer = XPCNativeWrapper.unwrap(buffer);
proxy.readPixels(x, height - y - 1, 1, 1, context.RGBA, context.UNSIGNED_BYTE, buffer);
return { r: buffer[0], g: buffer[1], b: buffer[2], a: buffer[3] };
}, {
request: {
selector: Option(0, "string"),
position: Option(0, "json")
},
response: { pixels: RetVal("json") }
}),
/**
* Events emitted by this actor. The "program-linked" event is fired
* every time a WebGL program was linked with its respective two shaders.
*/
events: {
"program-linked": {
type: "programLinked",
program: Arg(0, "gl-program")
},
"global-destroyed": {
type: "globalDestroyed",
program: Arg(0, "number")
},
"global-created": {
type: "globalCreated",
program: Arg(0, "number")
}
},
/**
* Gets an array of all cached program actors belonging to all windows.
* This should only be used for tests.
*/
_getAllPrograms: method(function() {
return this._programActorsCache;
}, {
response: { programs: RetVal("array:gl-program") }
}),
/**
* Invoked whenever the current tab actor's document global is created.
*/
_onGlobalCreated: function({id, window, isTopLevel}) {
if (isTopLevel) {
WebGLInstrumenter.handle(window, this._webglObserver);
events.emit(this, "global-created", id);
}
},
/**
* Invoked whenever the current tab actor's inner window is destroyed.
*/
_onGlobalDestroyed: function({id, isTopLevel, isFrozen}) {
if (isTopLevel && !isFrozen) {
removeFromArray(this._programActorsCache, e => e.ownerWindow == id);
this._webglObserver.unregisterContextsForWindow(id);
events.emit(this, "global-destroyed", id);
}
},
/**
* Invoked whenever an observed WebGL context links a program.
*/
_onProgramLinked: function(...args) {
let programActor = new ProgramActor(this.conn, args);
this._programActorsCache.push(programActor);
events.emit(this, "program-linked", programActor);
}
});
/**
* The corresponding Front object for the WebGLActor.
*/
var WebGLFront = exports.WebGLFront = protocol.FrontClass(WebGLActor, {
initialize: function(client, { webglActor }) {
protocol.Front.prototype.initialize.call(this, client, { actor: webglActor });
this.manage(this);
}
});
/**
* Instruments a HTMLCanvasElement with the appropriate inspection methods.
*/
var WebGLInstrumenter = {
/**
* Overrides the getContext method in the HTMLCanvasElement prototype.
*
* @param nsIDOMWindow window
* The window to perform the instrumentation in.
* @param WebGLObserver observer
* The observer watching function calls in the context.
*/
handle: function(window, observer) {
let self = this;
let id = ContentObserver.GetInnerWindowID(window);
let canvasElem = XPCNativeWrapper.unwrap(window.HTMLCanvasElement);
let canvasPrototype = canvasElem.prototype;
let originalGetContext = canvasPrototype.getContext;
/**
* Returns a drawing context on the canvas, or null if the context ID is
* not supported. This override creates an observer for the targeted context
* type and instruments specific functions in the targeted context instance.
*/
canvasPrototype.getContext = function(name, options) {
// Make sure a context was able to be created.
let context = originalGetContext.call(this, name, options);
if (!context) {
return context;
}
// Make sure a WebGL (not a 2D) context will be instrumented.
if (WEBGL_CONTEXT_NAMES.indexOf(name) == -1) {
return context;
}
// Repeated calls to 'getContext' return the same instance, no need to
// instrument everything again.
if (observer.for(context)) {
return context;
}
// Create a separate state storage for this context.
observer.registerContextForWindow(id, context);
// Link our observer to the new WebGL context methods.
for (let { timing, callback, functions } of self._methods) {
for (let func of functions) {
self._instrument(observer, context, func, callback, timing);
}
}
// Return the decorated context back to the content consumer, which
// will continue using it normally.
return context;
};
},
/**
* Overrides a specific method in a HTMLCanvasElement context.
*
* @param WebGLObserver observer
* The observer watching function calls in the context.
* @param WebGLRenderingContext context
* The targeted WebGL context instance.
* @param string funcName
* The function to override.
* @param array callbackName [optional]
* The two callback function names in the observer, corresponding to
* the "before" and "after" invocation times. If unspecified, they will
* default to the name of the function to override.
* @param number timing [optional]
* When to issue the callback in relation to the actual context
* function call. Availalble values are -1 for "before" (default)
* 1 for "after" and 0 for "before and after".
*/
_instrument: function(observer, context, funcName, callbackName = [], timing = -1) {
let { cache, proxy } = observer.for(context);
let originalFunc = context[funcName];
let beforeFuncName = callbackName[0] || funcName;
let afterFuncName = callbackName[1] || callbackName[0] || funcName;
context[funcName] = function(...glArgs) {
if (timing <= 0 && !observer.suppressHandlers) {
let glBreak = observer[beforeFuncName](glArgs, cache, proxy);
if (glBreak) return undefined;
}
// Invoking .apply on an unxrayed content function doesn't work, because
// the arguments array is inaccessible to it. Get Xrays back.
let glResult = Cu.waiveXrays(Cu.unwaiveXrays(originalFunc).apply(this, glArgs));
if (timing >= 0 && !observer.suppressHandlers) {
let glBreak = observer[afterFuncName](glArgs, glResult, cache, proxy);
if (glBreak) return undefined;
}
return glResult;
};
},
/**
* Override mappings for WebGL methods.
*/
_methods: [{
timing: 1, // after
functions: [
"linkProgram", "getAttribLocation", "getUniformLocation"
]
}, {
timing: -1, // before
callback: [
"toggleVertexAttribArray"
],
functions: [
"enableVertexAttribArray", "disableVertexAttribArray"
]
}, {
timing: -1, // before
callback: [
"attribute_"
],
functions: [
"vertexAttrib1f", "vertexAttrib2f", "vertexAttrib3f", "vertexAttrib4f",
"vertexAttrib1fv", "vertexAttrib2fv", "vertexAttrib3fv", "vertexAttrib4fv",
"vertexAttribPointer"
]
}, {
timing: -1, // before
callback: [
"uniform_"
],
functions: [
"uniform1i", "uniform2i", "uniform3i", "uniform4i",
"uniform1f", "uniform2f", "uniform3f", "uniform4f",
"uniform1iv", "uniform2iv", "uniform3iv", "uniform4iv",
"uniform1fv", "uniform2fv", "uniform3fv", "uniform4fv",
"uniformMatrix2fv", "uniformMatrix3fv", "uniformMatrix4fv"
]
}, {
timing: -1, // before
functions: [
"useProgram", "enable", "disable", "blendColor",
"blendEquation", "blendEquationSeparate",
"blendFunc", "blendFuncSeparate"
]
}, {
timing: 0, // before and after
callback: [
"beforeDraw_", "afterDraw_"
],
functions: [
"drawArrays", "drawElements"
]
}]
// TODO: It'd be a good idea to handle other functions as well:
// - getActiveUniform
// - getUniform
// - getActiveAttrib
// - getVertexAttrib
};
/**
* An observer that captures a WebGL context's method calls.
*/
function WebGLObserver() {
this._contexts = new Map();
}
WebGLObserver.prototype = {
_contexts: null,
/**
* Creates a WebGLCache and a WebGLProxy for the specified window and context.
*
* @param number id
* The id of the window containing the WebGL context.
* @param WebGLRenderingContext context
* The WebGL context used in the cache and proxy instances.
*/
registerContextForWindow: function(id, context) {
let cache = new WebGLCache(id, context);
let proxy = new WebGLProxy(id, context, cache, this);
cache.refreshState(proxy);
this._contexts.set(context, {
ownerWindow: id,
cache: cache,
proxy: proxy
});
},
/**
* Removes all WebGLCache and WebGLProxy instances for a particular window.
*
* @param number id
* The id of the window containing the WebGL context.
*/
unregisterContextsForWindow: function(id) {
removeFromMap(this._contexts, e => e.ownerWindow == id);
},
/**
* Gets the WebGLCache and WebGLProxy instances for a particular context.
*
* @param WebGLRenderingContext context
* The WebGL context used in the cache and proxy instances.
* @return object
* An object containing the corresponding { cache, proxy } instances.
*/
for: function(context) {
return this._contexts.get(context);
},
/**
* Set this flag to true to stop observing any context function calls.
*/
suppressHandlers: false,
/**
* Called immediately *after* 'linkProgram' is requested in the context.
*
* @param array glArgs
* Overridable arguments with which the function is called.
* @param void glResult
* The returned value of the original function call.
* @param WebGLCache cache
* The state storage for the WebGL context initiating this call.
* @param WebGLProxy proxy
* The proxy methods for the WebGL context initiating this call.
*/
linkProgram: function(glArgs, glResult, cache, proxy) {
let program = glArgs[0];
let shaders = proxy.getAttachedShaders(program);
cache.addProgram(program, PROGRAM_DEFAULT_TRAITS);
emit(this, "program-linked", program, shaders, cache, proxy);
},
/**
* Called immediately *after* 'getAttribLocation' is requested in the context.
*
* @param array glArgs
* Overridable arguments with which the function is called.
* @param GLint glResult
* The returned value of the original function call.
* @param WebGLCache cache
* The state storage for the WebGL context initiating this call.
*/
getAttribLocation: function(glArgs, glResult, cache) {
// Make sure the attribute's value is legal before caching.
if (glResult < 0) {
return;
}
let [program, name] = glArgs;
cache.addAttribute(program, name, glResult);
},
/**
* Called immediately *after* 'getUniformLocation' is requested in the context.
*
* @param array glArgs
* Overridable arguments with which the function is called.
* @param WebGLUniformLocation glResult
* The returned value of the original function call.
* @param WebGLCache cache
* The state storage for the WebGL context initiating this call.
*/
getUniformLocation: function(glArgs, glResult, cache) {
// Make sure the uniform's value is legal before caching.
if (!glResult) {
return;
}
let [program, name] = glArgs;
cache.addUniform(program, name, glResult);
},
/**
* Called immediately *before* 'enableVertexAttribArray' or
* 'disableVertexAttribArray'is requested in the context.
*
* @param array glArgs
* Overridable arguments with which the function is called.
* @param WebGLCache cache
* The state storage for the WebGL context initiating this call.
*/
toggleVertexAttribArray: function(glArgs, cache) {
glArgs[0] = cache.getCurrentAttributeLocation(glArgs[0]);
return glArgs[0] < 0; // Return true to break original function call.
},
/**
* Called immediately *before* 'attribute_' is requested in the context.
*
* @param array glArgs
* Overridable arguments with which the function is called.
* @param WebGLCache cache
* The state storage for the WebGL context initiating this call.
*/
attribute_: function(glArgs, cache) {
glArgs[0] = cache.getCurrentAttributeLocation(glArgs[0]);
return glArgs[0] < 0; // Return true to break original function call.
},
/**
* Called immediately *before* 'uniform_' is requested in the context.
*
* @param array glArgs
* Overridable arguments with which the function is called.
* @param WebGLCache cache
* The state storage for the WebGL context initiating this call.
*/
uniform_: function(glArgs, cache) {
glArgs[0] = cache.getCurrentUniformLocation(glArgs[0]);
return !glArgs[0]; // Return true to break original function call.
},
/**
* Called immediately *before* 'useProgram' is requested in the context.
*
* @param array glArgs
* Overridable arguments with which the function is called.
* @param WebGLCache cache
* The state storage for the WebGL context initiating this call.
*/
useProgram: function(glArgs, cache) {
// Manually keeping a cache and not using gl.getParameter(CURRENT_PROGRAM)
// because gl.get* functions are slow as potatoes.
cache.currentProgram = glArgs[0];
},
/**
* Called immediately *before* 'enable' is requested in the context.
*
* @param array glArgs
* Overridable arguments with which the function is called.
* @param WebGLCache cache
* The state storage for the WebGL context initiating this call.
*/
enable: function(glArgs, cache) {
cache.currentState[glArgs[0]] = true;
},
/**
* Called immediately *before* 'disable' is requested in the context.
*
* @param array glArgs
* Overridable arguments with which the function is called.
* @param WebGLCache cache
* The state storage for the WebGL context initiating this call.
*/
disable: function(glArgs, cache) {
cache.currentState[glArgs[0]] = false;
},
/**
* Called immediately *before* 'blendColor' is requested in the context.
*
* @param array glArgs
* Overridable arguments with which the function is called.
* @param WebGLCache cache
* The state storage for the WebGL context initiating this call.
*/
blendColor: function(glArgs, cache) {
let blendColor = cache.currentState.blendColor;
blendColor[0] = glArgs[0];
blendColor[1] = glArgs[1];
blendColor[2] = glArgs[2];
blendColor[3] = glArgs[3];
},
/**
* Called immediately *before* 'blendEquation' is requested in the context.
*
* @param array glArgs
* Overridable arguments with which the function is called.
* @param WebGLCache cache
* The state storage for the WebGL context initiating this call.
*/
blendEquation: function(glArgs, cache) {
let state = cache.currentState;
state.blendEquationRgb = state.blendEquationAlpha = glArgs[0];
},
/**
* Called immediately *before* 'blendEquationSeparate' is requested in the context.
*
* @param array glArgs
* Overridable arguments with which the function is called.
* @param WebGLCache cache
* The state storage for the WebGL context initiating this call.
*/
blendEquationSeparate: function(glArgs, cache) {
let state = cache.currentState;
state.blendEquationRgb = glArgs[0];
state.blendEquationAlpha = glArgs[1];
},
/**
* Called immediately *before* 'blendFunc' is requested in the context.
*
* @param array glArgs
* Overridable arguments with which the function is called.
* @param WebGLCache cache
* The state storage for the WebGL context initiating this call.
*/
blendFunc: function(glArgs, cache) {
let state = cache.currentState;
state.blendSrcRgb = state.blendSrcAlpha = glArgs[0];
state.blendDstRgb = state.blendDstAlpha = glArgs[1];
},
/**
* Called immediately *before* 'blendFuncSeparate' is requested in the context.
*
* @param array glArgs
* Overridable arguments with which the function is called.
* @param WebGLCache cache
* The state storage for the WebGL context initiating this call.
*/
blendFuncSeparate: function(glArgs, cache) {
let state = cache.currentState;
state.blendSrcRgb = glArgs[0];
state.blendDstRgb = glArgs[1];
state.blendSrcAlpha = glArgs[2];
state.blendDstAlpha = glArgs[3];
},
/**
* Called immediately *before* 'drawArrays' or 'drawElements' is requested
* in the context.
*
* @param array glArgs
* Overridable arguments with which the function is called.
* @param WebGLCache cache
* The state storage for the WebGL context initiating this call.
* @param WebGLProxy proxy
* The proxy methods for the WebGL context initiating this call.
*/
beforeDraw_: function(glArgs, cache, proxy) {
let traits = cache.currentProgramTraits;
// Handle program blackboxing.
if (traits & PROGRAM_BLACKBOX_TRAIT) {
return true; // Return true to break original function call.
}
// Handle program highlighting.
if (traits & PROGRAM_HIGHLIGHT_TRAIT) {
proxy.enableHighlighting();
}
return false;
},
/**
* Called immediately *after* 'drawArrays' or 'drawElements' is requested
* in the context.
*
* @param array glArgs
* Overridable arguments with which the function is called.
* @param void glResult
* The returned value of the original function call.
* @param WebGLCache cache
* The state storage for the WebGL context initiating this call.
* @param WebGLProxy proxy
* The proxy methods for the WebGL context initiating this call.
*/
afterDraw_: function(glArgs, glResult, cache, proxy) {
let traits = cache.currentProgramTraits;
// Handle program highlighting.
if (traits & PROGRAM_HIGHLIGHT_TRAIT) {
proxy.disableHighlighting();
}
}
};
/**
* A mechanism for storing a single WebGL context's state, programs, shaders,
* attributes or uniforms.
*
* @param number id
* The id of the window containing the WebGL context.
* @param WebGLRenderingContext context
* The WebGL context for which the state is stored.
*/
function WebGLCache(id, context) {
this._id = id;
this._gl = context;
this._programs = new Map();
this.currentState = {};
}
WebGLCache.prototype = {
_id: 0,
_gl: null,
_programs: null,
_currentProgramInfo: null,
_currentAttributesMap: null,
_currentUniformsMap: null,
get ownerWindow() {
return this._id;
},
get ownerContext() {
return this._gl;
},
/**
* A collection of flags or properties representing the context's state.
* Implemented as an object hash and not a Map instance because keys are
* always either strings or numbers.
*/
currentState: null,
/**
* Populates the current state with values retrieved from the context.
*
* @param WebGLProxy proxy
* The proxy methods for the WebGL context owning the state.
*/
refreshState: function(proxy) {
let gl = this._gl;
let s = this.currentState;
// Populate only with the necessary parameters. Not all default WebGL
// state values are required.
s[gl.BLEND] = proxy.isEnabled("BLEND");
s.blendColor = proxy.getParameter("BLEND_COLOR");
s.blendEquationRgb = proxy.getParameter("BLEND_EQUATION_RGB");
s.blendEquationAlpha = proxy.getParameter("BLEND_EQUATION_ALPHA");
s.blendSrcRgb = proxy.getParameter("BLEND_SRC_RGB");
s.blendSrcAlpha = proxy.getParameter("BLEND_SRC_ALPHA");
s.blendDstRgb = proxy.getParameter("BLEND_DST_RGB");
s.blendDstAlpha = proxy.getParameter("BLEND_DST_ALPHA");
},
/**
* Adds a program to the cache.
*
* @param WebGLProgram program
* The shader for which the traits are to be cached.
* @param number traits
* A default properties mask set for the program.
*/
addProgram: function(program, traits) {
this._programs.set(program, {
traits: traits,
attributes: [], // keys are GLints (numbers)
uniforms: new Map() // keys are WebGLUniformLocations (objects)
});
},
/**
* Adds a specific trait to a program. The effect of such properties is
* determined by the consumer of this cache.
*
* @param WebGLProgram program
* The program to add the trait to.
* @param number trait
* The property added to the program.
*/
setProgramTrait: function(program, trait) {
this._programs.get(program).traits |= trait;
},
/**
* Removes a specific trait from a program.
*
* @param WebGLProgram program
* The program to remove the trait from.
* @param number trait
* The property removed from the program.
*/
unsetProgramTrait: function(program, trait) {
this._programs.get(program).traits &= ~trait;
},
/**
* Sets the currently used program in the context.
* @param WebGLProgram program
*/
set currentProgram(program) {
let programInfo = this._programs.get(program);
if (programInfo == null) {
return;
}
this._currentProgramInfo = programInfo;
this._currentAttributesMap = programInfo.attributes;
this._currentUniformsMap = programInfo.uniforms;
},
/**
* Gets the traits for the currently used program.
* @return number
*/
get currentProgramTraits() {
return this._currentProgramInfo.traits;
},
/**
* Adds an attribute to the cache.
*
* @param WebGLProgram program
* The program for which the attribute is bound.
* @param string name
* The attribute name.
* @param GLint value
* The attribute value.
*/
addAttribute: function(program, name, value) {
this._programs.get(program).attributes[value] = {
name: name,
value: value
};
},
/**
* Adds a uniform to the cache.
*
* @param WebGLProgram program
* The program for which the uniform is bound.
* @param string name
* The uniform name.
* @param WebGLUniformLocation value
* The uniform value.
*/
addUniform: function(program, name, value) {
this._programs.get(program).uniforms.set(new XPCNativeWrapper(value), {
name: name,
value: value
});
},
/**
* Updates the attribute locations for a specific program.
* This is necessary, for example, when the shader is relinked and all the
* attribute locations become obsolete.
*
* @param WebGLProgram program
* The program for which the attributes need updating.
*/
updateAttributesForProgram: function(program) {
let attributes = this._programs.get(program).attributes;
for (let attribute of attributes) {
attribute.value = this._gl.getAttribLocation(program, attribute.name);
}
},
/**
* Updates the uniform locations for a specific program.
* This is necessary, for example, when the shader is relinked and all the
* uniform locations become obsolete.
*
* @param WebGLProgram program
* The program for which the uniforms need updating.
*/
updateUniformsForProgram: function(program) {
let uniforms = this._programs.get(program).uniforms;
for (let [, uniform] of uniforms) {
uniform.value = this._gl.getUniformLocation(program, uniform.name);
}
},
/**
* Gets the actual attribute location in a specific program.
* When relinked, all the attribute locations become obsolete and are updated
* in the cache. This method returns the (current) real attribute location.
*
* @param GLint initialValue
* The initial attribute value.
* @return GLint
* The current attribute value, or the initial value if it's already
* up to date with its corresponding program.
*/
getCurrentAttributeLocation: function(initialValue) {
let attributes = this._currentAttributesMap;
let currentInfo = attributes ? attributes[initialValue] : null;
return currentInfo ? currentInfo.value : initialValue;
},
/**
* Gets the actual uniform location in a specific program.
* When relinked, all the uniform locations become obsolete and are updated
* in the cache. This method returns the (current) real uniform location.
*
* @param WebGLUniformLocation initialValue
* The initial uniform value.
* @return WebGLUniformLocation
* The current uniform value, or the initial value if it's already
* up to date with its corresponding program.
*/
getCurrentUniformLocation: function(initialValue) {
let uniforms = this._currentUniformsMap;
let currentInfo = uniforms ? uniforms.get(initialValue) : null;
return currentInfo ? currentInfo.value : initialValue;
}
};
/**
* A mechanism for injecting or qureying state into/from a single WebGL context.
*
* Any interaction with a WebGL context should go through this proxy.
* Otherwise, the corresponding observer would register the calls as coming
* from content, which is usually not desirable. Infinite call stacks are bad.
*
* @param number id
* The id of the window containing the WebGL context.
* @param WebGLRenderingContext context
* The WebGL context used for the proxy methods.
* @param WebGLCache cache
* The state storage for the corresponding context.
* @param WebGLObserver observer
* The observer watching function calls in the corresponding context.
*/
function WebGLProxy(id, context, cache, observer) {
this._id = id;
this._gl = context;
this._cache = cache;
this._observer = observer;
let exports = [
"isEnabled",
"getParameter",
"getAttachedShaders",
"getShaderSource",
"getShaderOfType",
"compileShader",
"enableHighlighting",
"disableHighlighting",
"readPixels"
];
exports.forEach(e => this[e] = (...args) => this._call(e, args));
}
WebGLProxy.prototype = {
_id: 0,
_gl: null,
_cache: null,
_observer: null,
get ownerWindow() {
return this._id;
},
get ownerContext() {
return this._gl;
},
/**
* Test whether a WebGL capability is enabled.
*
* @param string name
* The WebGL capability name, for example "BLEND".
* @return boolean
* True if enabled, false otherwise.
*/
_isEnabled: function(name) {
return this._gl.isEnabled(this._gl[name]);
},
/**
* Returns the value for the specified WebGL parameter name.
*
* @param string name
* The WebGL parameter name, for example "BLEND_COLOR".
* @return any
* The corresponding parameter's value.
*/
_getParameter: function(name) {
return this._gl.getParameter(this._gl[name]);
},
/**
* Returns the renderbuffer property value for the specified WebGL parameter.
* If no renderbuffer binding is available, null is returned.
*
* @param string name
* The WebGL parameter name, for example "BLEND_COLOR".
* @return any
* The corresponding parameter's value.
*/
_getRenderbufferParameter: function(name) {
if (!this._getParameter("RENDERBUFFER_BINDING")) {
return null;
}
let gl = this._gl;
return gl.getRenderbufferParameter(gl.RENDERBUFFER, gl[name]);
},
/**
* Returns the framebuffer property value for the specified WebGL parameter.
* If no framebuffer binding is available, null is returned.
*
* @param string type
* The framebuffer object attachment point, for example "COLOR_ATTACHMENT0".
* @param string name
* The WebGL parameter name, for example "FRAMEBUFFER_ATTACHMENT_OBJECT_NAME".
* If unspecified, defaults to "FRAMEBUFFER_ATTACHMENT_OBJECT_TYPE".
* @return any
* The corresponding parameter's value.
*/
_getFramebufferAttachmentParameter: function(type, name = "FRAMEBUFFER_ATTACHMENT_OBJECT_TYPE") {
if (!this._getParameter("FRAMEBUFFER_BINDING")) {
return null;
}
let gl = this._gl;
return gl.getFramebufferAttachmentParameter(gl.FRAMEBUFFER, gl[type], gl[name]);
},
/**
* Returns the shader objects attached to a program object.
*
* @param WebGLProgram program
* The program for which to retrieve the attached shaders.
* @return array
* The attached vertex and fragment shaders.
*/
_getAttachedShaders: function(program) {
return this._gl.getAttachedShaders(program);
},
/**
* Returns the source code string from a shader object.
*
* @param WebGLShader shader
* The shader for which to retrieve the source code.
* @return string
* The shader's source code.
*/
_getShaderSource: function(shader) {
return this._gl.getShaderSource(shader);
},
/**
* Finds a shader of the specified type in a list.
*
* @param WebGLShader[] shaders
* The shaders for which to check the type.
* @param string type
* Either "vertex" or "fragment".
* @return WebGLShader | null
* The shader of the specified type, or null if nothing is found.
*/
_getShaderOfType: function(shaders, type) {
let gl = this._gl;
let shaderTypeEnum = {
vertex: gl.VERTEX_SHADER,
fragment: gl.FRAGMENT_SHADER
}[type];
for (let shader of shaders) {
if (gl.getShaderParameter(shader, gl.SHADER_TYPE) == shaderTypeEnum) {
return shader;
}
}
return null;
},
/**
* Changes a shader's source code and relinks the respective program.
*
* @param WebGLProgram program
* The program who's linked shader is to be modified.
* @param WebGLShader shader
* The shader to be modified.
* @param string text
* The new shader source code.
* @return object
* An object containing the compilation and linking status.
*/
_compileShader: function(program, shader, text) {
let gl = this._gl;
gl.shaderSource(shader, text);
gl.compileShader(shader);
gl.linkProgram(program);
let error = { compile: "", link: "" };
if (!gl.getShaderParameter(shader, gl.COMPILE_STATUS)) {
error.compile = gl.getShaderInfoLog(shader);
}
if (!gl.getProgramParameter(program, gl.LINK_STATUS)) {
error.link = gl.getShaderInfoLog(shader);
}
this._cache.updateAttributesForProgram(program);
this._cache.updateUniformsForProgram(program);
return error;
},
/**
* Enables color blending based on the geometry highlight tint.
*/
_enableHighlighting: function() {
let gl = this._gl;
// Avoid changing the blending params when "rendering to texture".
// Check drawing to a custom framebuffer bound to the default renderbuffer.
let hasFramebuffer = this._getParameter("FRAMEBUFFER_BINDING");
let hasRenderbuffer = this._getParameter("RENDERBUFFER_BINDING");
if (hasFramebuffer && !hasRenderbuffer) {
return;
}
// Check drawing to a depth or stencil component of the framebuffer.
let writesDepth = this._getFramebufferAttachmentParameter("DEPTH_ATTACHMENT");
let writesStencil = this._getFramebufferAttachmentParameter("STENCIL_ATTACHMENT");
if (writesDepth || writesStencil) {
return;
}
// Non-premultiplied alpha blending based on a predefined constant color.
// Simply using gl.colorMask won't work, because we want non-tinted colors
// to be drawn as black, not ignored.
gl.enable(gl.BLEND);
gl.blendColor.apply(gl, this.highlightTint);
gl.blendEquation(gl.FUNC_ADD);
gl.blendFunc(gl.CONSTANT_COLOR, gl.ONE_MINUS_SRC_ALPHA, gl.CONSTANT_COLOR, gl.ZERO);
this.wasHighlighting = true;
},
/**
* Disables color blending based on the geometry highlight tint, by
* reverting the corresponding params back to their original values.
*/
_disableHighlighting: function() {
let gl = this._gl;
let s = this._cache.currentState;
gl[s[gl.BLEND] ? "enable" : "disable"](gl.BLEND);
gl.blendColor.apply(gl, s.blendColor);
gl.blendEquationSeparate(s.blendEquationRgb, s.blendEquationAlpha);
gl.blendFuncSeparate(s.blendSrcRgb, s.blendDstRgb, s.blendSrcAlpha, s.blendDstAlpha);
},
/**
* Returns the pixel values at the position specified on the canvas.
*/
_readPixels: function(x, y, w, h, format, type, buffer) {
this._gl.readPixels(x, y, w, h, format, type, buffer);
},
/**
* The color tint used for highlighting geometry.
* @see _enableHighlighting and _disableHighlighting.
*/
highlightTint: [0, 0, 0, 0],
/**
* Executes a function in this object.
*
* This method makes sure that any handlers in the context observer are
* suppressed, hence stopping observing any context function calls.
*
* @param string funcName
* The function to call.
* @param array args
* An array of arguments.
* @return any
* The called function result.
*/
_call: function(funcName, args) {
let prevState = this._observer.suppressHandlers;
this._observer.suppressHandlers = true;
let result = this["_" + funcName].apply(this, args);
this._observer.suppressHandlers = prevState;
return result;
}
};
// Utility functions.
function removeFromMap(map, predicate) {
for (let [key, value] of map) {
if (predicate(value)) {
map.delete(key);
}
}
};
function removeFromArray(array, predicate) {
for (let i = 0; i < array.length;) {
if (predicate(array[i])) {
array.splice(i, 1);
} else {
i++;
}
}
}