cables_dev/cables/src/core/cgl/cgl_state.js

import { Logger } from "cables-shared-client";
import { CONSTANTS } from "./constants.js";
import { Shader } from "./cgl_shader.js";
import { ProfileData } from "./cgl_profiledata.js";
import { CGState } from "../cg/cg_state.js";
import { CG } from "../cg/cg_constants.js";


/**
 * cables gl context/state manager
 * @class
 * @namespace external:CGL
 * @hideconstructor
 */
// const Context(_patch)
class Context extends CGState
{
    constructor(_patch)
    {
        super(_patch);
        // EventTarget.apply(this);
        // CGState.apply(this);

        this.gApi = CG.GAPI_WEBGL;
        this.aborted = false;

        this.pushMvMatrix = this.pushModelMatrix; // deprecated and wrong... still used??
        this.popMvMatrix = this.popmMatrix = this.popModelMatrix;// deprecated and wrong... still used??

        this.profileData = new ProfileData(this);
        this._log = new Logger("cgl_context", { "onError": _patch.config.onError });
        this._viewPort = [0, 0, 0, 0];
        this.glVersion = 0;
        this.glUseHalfFloatTex = false;
        this.clearCanvasTransparent = true;
        this.clearCanvasDepth = true;
        this.debugOneFrame = false;
        this.checkGlErrors = false; // true is slow // false should be default...
        this.maxTextureUnits = 0;
        this.maxVaryingVectors = 0;
        this.currentProgram = null;
        this._hadStackError = false;
        this.glSlowRenderer = false;
        this._isSafariCrap = false;

        this.temporaryTexture = null;
        this.frameStore = {};
        this._onetimeCallbacks = [];
        this.gl = null;

        this._cursor = "auto";
        this._currentCursor = "";

        this._viewPortStack = [];
        this._glFrameBufferStack = [];
        this._frameBufferStack = [];
        this._shaderStack = [];
        this._stackDepthTest = [];
        this.mainloopOp = null;

        this._simpleShader = new Shader(this, "simpleshader");
        this._simpleShader.setModules(["MODULE_VERTEX_POSITION", "MODULE_COLOR", "MODULE_BEGIN_FRAG", "MODULE_VERTEX_MODELVIEW"]);
        this._simpleShader.setSource(Shader.getDefaultVertexShader(), Shader.getDefaultFragmentShader());

        this._currentShader = this._simpleShader;


        this._oldCanvasWidth = -1;
        this._oldCanvasHeight = -1;
        this._enabledExtensions = {};
    }

    // set pixelDensity(p)
    // {
    //     this._pixelDensity = p;
    // }

    // get pixelDensity()
    // {
    //     return this._pixelDensity;
    // }



    get viewPort()
    {
        if (this._viewPortStack.length > 3)
        {
            const l = this._viewPortStack.length;

            return [
                this._viewPortStack[l - 4],
                this._viewPortStack[l - 3],
                this._viewPortStack[l - 2],
                this._viewPortStack[l - 1]
            ];
        }
        else
        {
            // workaround pre viewport stack times / or+and initial value...

            return this._viewPort;
        }
    }



    get mvMatrix() // deprecate
    {
        return this.mMatrix;
    }

    set mvMatrix(m) // deprecate
    {
        this.mMatrix = m;
    }


    _setCanvas(canv)
    {
        if (!canv)
        {
            this._log.stack("_setCanvas undef");
        }

        if (!this.patch.config.canvas) this.patch.config.canvas = {};
        if (!this.patch.config.canvas.hasOwnProperty("preserveDrawingBuffer")) this.patch.config.canvas.preserveDrawingBuffer = false;
        if (!this.patch.config.canvas.hasOwnProperty("premultipliedAlpha")) this.patch.config.canvas.premultipliedAlpha = false;
        if (!this.patch.config.canvas.hasOwnProperty("alpha")) this.patch.config.canvas.alpha = false;

        this.patch.config.canvas.stencil = true;

        if (this.patch.config.hasOwnProperty("clearCanvasColor")) this.clearCanvasTransparent = this.patch.config.clearCanvasColor;
        if (this.patch.config.hasOwnProperty("clearCanvasDepth")) this.clearCanvasDepth = this.patch.config.clearCanvasDepth;

        // safari stuff..........
        if (/^((?!chrome|android).)*safari/i.test(navigator.userAgent) && (navigator.userAgent.match(/iPhone/i)))
        {
            this._isSafariCrap = true;
            this.glUseHalfFloatTex = true;
        }

        if (!this.patch.config.canvas.forceWebGl1) this.gl = canv.getContext("webgl2", this.patch.config.canvas);


        if (!this.gl || this.gl.isContextLost())
        {
            this.aborted = true;
            this._log.error("NO_WEBGL", "sorry, could not initialize WebGL. Please check if your Browser supports WebGL or try to restart your browser.");
            return;
        }

        if (this.gl.getParameter(this.gl.VERSION) != "WebGL 1.0")
        {
            this.glVersion = 2;
        }
        else
        {
            this.gl = canv.getContext("webgl", this.patch.config.canvas) || canv.getContext("experimental-webgl", this.patch.config.canvas);
            this.glVersion = 1;

            // safari
            // if (/^((?!chrome|android).)*safari/i.test(navigator.userAgent) && (navigator.userAgent.match(/iPhone/i)))
            // {
            //     this.glUseHalfFloatTex = true;
            // }

            // ios
            if (/iPad|iPhone|iPod/.test(navigator.userAgent) && !window.MSStream)
            {
                if (!this.patch.config.canvas.hasOwnProperty("powerPreference")) this.patch.config.canvas.powerPreference = "high-performance";
            }

            this.enableExtension("OES_standard_derivatives");
            // this.enableExtension("GL_OES_standard_derivatives");
            const instancingExt = this.enableExtension("ANGLE_instanced_arrays") || this.gl;
            if (instancingExt.vertexAttribDivisorANGLE)
            {
                this.gl.vertexAttribDivisor = instancingExt.vertexAttribDivisorANGLE.bind(instancingExt);
                this.gl.drawElementsInstanced = instancingExt.drawElementsInstancedANGLE.bind(instancingExt);
            }
        }

        const dbgRenderInfo = this.enableExtension("WEBGL_debug_renderer_info");
        if (dbgRenderInfo)
        {
            this.glRenderer = this.gl.getParameter(dbgRenderInfo.UNMASKED_RENDERER_WEBGL);
            if (this.glRenderer === "Google SwiftShader") this.glSlowRenderer = true;
        }

        this.canvas.addEventListener("webglcontextlost", (event) =>
        {
            if (this.aborted) return this._log.warn("[cgl_state] aborted context lost... can be ignored...");
            this._log.error("canvas lost...", event);
            this.emitEvent("webglcontextlost");
            this.aborted = true;
        });


        this.maxAnisotropic = 0;
        if (this.enableExtension("EXT_texture_filter_anisotropic"))
            this.maxAnisotropic = this.gl.getParameter(this.enableExtension("EXT_texture_filter_anisotropic").MAX_TEXTURE_MAX_ANISOTROPY_EXT);


        this.maxVaryingVectors = this.gl.getParameter(this.gl.MAX_VARYING_VECTORS);
        this.maxTextureUnits = this.gl.getParameter(this.gl.MAX_TEXTURE_IMAGE_UNITS);
        this.maxTexSize = this.gl.getParameter(this.gl.MAX_TEXTURE_SIZE);
        this.maxUniformsFrag = this.gl.getParameter(this.gl.MAX_FRAGMENT_UNIFORM_VECTORS);
        this.maxUniformsVert = this.gl.getParameter(this.gl.MAX_VERTEX_UNIFORM_VECTORS);
        this.maxSamples = 0;
        if (this.gl.MAX_SAMPLES) this.maxSamples = this.gl.getParameter(this.gl.MAX_SAMPLES);

        if (this.glVersion == 1)
        {
            this.enableExtension("OES_standard_derivatives");
            const instancingExt = this.enableExtension("ANGLE_instanced_arrays") || this.gl;

            if (instancingExt.vertexAttribDivisorANGLE)
            {
                this.gl.vertexAttribDivisor = instancingExt.vertexAttribDivisorANGLE.bind(instancingExt);
                this.gl.drawElementsInstanced = instancingExt.drawElementsInstancedANGLE.bind(instancingExt);
            }
        }

        this.DEPTH_FUNCS = [
            this.gl.NEVER,
            this.gl.ALWAYS,
            this.gl.LESS,
            this.gl.LEQUAL,
            this.gl.GREATER,
            this.gl.GEQUAL,
            this.gl.EQUAL,
            this.gl.NOTEQUAL
        ];
        this.CULL_MODES = [
            null,
            this.gl.BACK,
            this.gl.FRONT,
            this.gl.FRONT_AND_BACK
        ];
    }

    getInfo()
    {
        return {
            "glVersion": this.glVersion,
            "glRenderer": this.glRenderer,
            "glUseHalfFloatTex": this.glUseHalfFloatTex,
            "maxVaryingVectors": this.maxVaryingVectors,
            "maxTextureUnits": this.maxTextureUnits,
            "maxTexSize": this.maxTexSize,
            "maxUniformsFrag": this.maxUniformsFrag,
            "maxUniformsVert": this.maxUniformsVert,
            "maxSamples": this.maxSamples
        };
    }





    /**
     * @function popViewPort
     * @memberof Context
     * @instance
     * @description pop viewPort stack
     */


    popViewPort()
    {
        this._viewPortStack.pop();
        this._viewPortStack.pop();
        this._viewPortStack.pop();
        this._viewPortStack.pop();

        if (this._viewPortStack.length == 0)
        {
            this.setViewPort(0, 0, this.canvasWidth, this.canvasHeight);
            // this.gl.viewport(this._viewPort[0], this._viewPort[1], this._viewPort[2], this._viewPort[3]);
            // this.setViewPort(this._viewPort[0], this._viewPort[1], this._viewPort[2], this._viewPort[3]);
        }
        else
        {
            // this.viewPort = [this._viewPortStack[this._viewPort.length - 4], this._viewPortStack[this._viewPort.length - 3], this._viewPortStack[this._viewPort.length - 2], this._viewPortStack[this._viewPort.length - 1]];
            // this.gl.viewport(this._viewPortStack[this._viewPort.length - 4], this._viewPortStack[this._viewPort.length - 3], this._viewPortStack[this._viewPort.length - 2], this._viewPortStack[this._viewPort.length - 1]);
            this.setViewPort(this._viewPortStack[this._viewPort.length - 4], this._viewPortStack[this._viewPort.length - 3], this._viewPortStack[this._viewPort.length - 2], this._viewPortStack[this._viewPort.length - 1]);
        }
    }

    /**
     * @function pushViewPort
     * @memberof Context
     * @instance
     * @description push a new viewport onto stack
     * @param {Number} x
     * @param {Number} y
     * @param {Number} w
     * @param {Number} h
     */

    pushViewPort(x, y, w, h)
    {
        this._viewPortStack.push(x, y, w, h);
        this.setViewPort(x, y, w, h);
    }


    // old
    getViewPort()
    {
        return this._viewPort;
    }

    // old
    resetViewPort()
    {
        this.gl.viewport(this._viewPort[0], this._viewPort[1], this._viewPort[2], this._viewPort[3]);
    }

    // old
    setViewPort(x, y, w, h)
    {
        this._viewPort[0] = Math.round(x);
        this._viewPort[1] = Math.round(y);
        this._viewPort[2] = Math.round(w);
        this._viewPort[3] = Math.round(h);
        this.gl.viewport(this._viewPort[0], this._viewPort[1], this._viewPort[2], this._viewPort[3]);
    }


    screenShot(cb, doScreenshotClearAlpha, mimeType, quality)
    {
        if (doScreenshotClearAlpha)
        {
            this.gl.clearColor(1, 1, 1, 1);
            this.gl.colorMask(false, false, false, true);
            this.gl.clear(this.gl.COLOR_BUFFER_BIT);
            this.gl.colorMask(true, true, true, true);
        }

        if (this.canvas && this.canvas.toBlob)
        {
            this.canvas.toBlob((blob) =>
            {
                if (cb) cb(blob);
                else this._log.log("no screenshot callback...");
            }, mimeType, quality);
        }
    }

    endFrame()
    {
        if (this.patch.isEditorMode()) CABLES.GL_MARKER.drawMarkerLayer(this);

        this.setPreviousShader();

        if (this._vMatrixStack.length() > 0) this.logStackError("view matrix stack length !=0 at end of rendering...");
        if (this._mMatrixStack.length() > 0) this.logStackError("mvmatrix stack length !=0 at end of rendering...");
        if (this._pMatrixStack.length() > 0) this.logStackError("pmatrix stack length !=0 at end of rendering...");
        if (this._glFrameBufferStack.length > 0) this.logStackError("glFrameBuffer stack length !=0 at end of rendering...");
        if (this._stackDepthTest.length > 0) this.logStackError("depthtest stack length !=0 at end of rendering...");
        if (this._stackDepthWrite.length > 0) this.logStackError("depthwrite stack length !=0 at end of rendering...");
        if (this._stackDepthFunc.length > 0) this.logStackError("depthfunc stack length !=0 at end of rendering...");
        if (this._stackBlend.length > 0) this.logStackError("blend stack length !=0 at end of rendering...");
        if (this._stackBlendMode.length > 0) this.logStackError("blendMode stack length !=0 at end of rendering...");
        if (this._shaderStack.length > 0) this.logStackError("this._shaderStack length !=0 at end of rendering...");
        if (this._stackCullFace.length > 0) this.logStackError("this._stackCullFace length !=0 at end of rendering...");
        if (this._stackCullFaceFacing.length > 0) this.logStackError("this._stackCullFaceFacing length !=0 at end of rendering...");
        if (this._viewPortStack.length > 0) this.logStackError("viewport stack length !=0 at end of rendering...");

        this._frameStarted = false;

        if (this._oldCanvasWidth != this.canvasWidth || this._oldCanvasHeight != this.canvasHeight)
        {
            this._oldCanvasWidth = this.canvasWidth;
            this._oldCanvasHeight = this.canvasHeight;
            this.emitEvent("resize");
        }

        if (this._cursor != this._currentCursor)
        {
            this._currentCursor = this.canvas.style.cursor = this._cursor;
        }

        this.emitEvent("endframe");

        this.fpsCounter.endFrame();
    }

    logStackError(str)
    {
        if (!this._hadStackError)
        {
            this._hadStackError = true;
            this._log.warn("[" + this.canvas.id + "]: ", str);
        }
    }

    // shader stack
    getShader()
    {
        if (this._currentShader) if (!this.frameStore || ((this.frameStore.renderOffscreen === true) == this._currentShader.offScreenPass) === true) return this._currentShader;

        for (let i = this._shaderStack.length - 1; i >= 0; i--) if (this._shaderStack[i]) if (this.frameStore.renderOffscreen == this._shaderStack[i].offScreenPass) return this._shaderStack[i];
    }

    getDefaultShader()
    {
        return this._simpleShader;
    }

    /**
     * push a shader to the shader stack
     * @function pushShader
     * @memberof Context
     * @instance
     * @param {Object} shader
     * @function
     */

    pushShader(shader)
    {
        if (this.frameStore.forceShaderMods)
        {
            for (let i = 0; i < this.frameStore.forceShaderMods.length; i++)
            {
                // if (!currentShader.forcedMod && currentShader != this.frameStore.forceShaderMods[i])
                // {
                //     currentShader.forcedMod = this.frameStore.forceShaderMods[i];
                shader = this.frameStore.forceShaderMods[i].bind(shader, false);
                // }
                // return currentShader;
                // if (this.frameStore.forceShaderMods[i].currentShader() && shader != this.frameStore.forceShaderMods[i].currentShader().shader)
            }
        }

        this._shaderStack.push(shader);
        this._currentShader = shader;
    }


    /**
     * pop current used shader from shader stack
     * @function popShader
     * @memberof Context
     * @instance
     * @function
     */
    setPreviousShader()
    {
        if (this.frameStore.forceShaderMods)
        {
            for (let i = 0; i < this.frameStore.forceShaderMods.length; i++)
            {
                // const a =
                this.frameStore.forceShaderMods[i].unbind(false);
                // if (a) return;
                // this.popShader();
            }
        }

        if (this._shaderStack.length === 0) throw new Error("Invalid shader stack pop!");
        this._shaderStack.pop();
        this._currentShader = this._shaderStack[this._shaderStack.length - 1];
    }

    /**
     * push a framebuffer to the framebuffer stack
     * @function pushGlFrameBuffer
     * @memberof Context
     * @instance
     * @param {Object} fb framebuffer
     * @function
     */
    pushGlFrameBuffer(fb)
    {
        this._glFrameBufferStack.push(fb);
    }

    /**
     * pop framebuffer stack
     * @function popGlFrameBuffer
     * @memberof Context
     * @instance
     * @returns {Object} current framebuffer or null
     */
    popGlFrameBuffer()
    {
        if (this._glFrameBufferStack.length == 0) return null;
        this._glFrameBufferStack.pop();
        return this._glFrameBufferStack[this._glFrameBufferStack.length - 1];
    }

    /**
     * get current framebuffer
     * @function getCurrentFrameBuffer
     * @memberof Context
     * @instance
     * @returns {Object} current framebuffer or null
     */
    getCurrentGlFrameBuffer()
    {
        if (this._glFrameBufferStack.length === 0) return null;
        return this._glFrameBufferStack[this._glFrameBufferStack.length - 1];
    }

    /**
     * push a framebuffer to the framebuffer stack
     * @function pushGlFrameBuffer
     * @memberof Context
     * @instance
     * @param {Framebuffer} fb framebuffer
     */
    pushFrameBuffer(fb)
    {
        this._frameBufferStack.push(fb);
    }

    /**
     * pop framebuffer stack
     * @function popFrameBuffer
     * @memberof Context
     * @instance
     * @returns {Framebuffer} current framebuffer or null
     */
    popFrameBuffer()
    {
        if (this._frameBufferStack.length == 0) return null;
        this._frameBufferStack.pop();
        return this._frameBufferStack[this._frameBufferStack.length - 1];
    }

    /**
     * get current framebuffer
     * @function getCurrentFrameBuffer
     * @memberof Context
     * @instance
     * @returns {Framebuffer} current framebuffer or null
     */
    getCurrentFrameBuffer()
    {
        if (this._frameBufferStack.length === 0) return null;
        return this._frameBufferStack[this._frameBufferStack.length - 1];
    }


    renderStart(cgl, identTranslate, identTranslateView)
    {
        this.fpsCounter.startFrame();
        this.pushDepthTest(true);
        this.pushDepthWrite(true);
        this.pushDepthFunc(cgl.gl.LEQUAL);
        this.pushCullFaceFacing(cgl.gl.BACK);
        this.pushCullFace(false);

        // if (this.clearCanvasTransparent)
        // {
        //     cgl.gl.clearColor(0, 0, 0, 0);
        //     cgl.gl.clear(cgl.gl.COLOR_BUFFER_BIT);
        // }
        // if (this.clearCanvasDepth) cgl.gl.clear(cgl.gl.DEPTH_BUFFER_BIT);

        cgl.setViewPort(0, 0, cgl.canvasWidth, cgl.canvasHeight);

        this._startMatrixStacks(identTranslate, identTranslateView);

        cgl.pushBlendMode(CONSTANTS.BLEND_MODES.BLEND_NORMAL, false);

        for (let i = 0; i < this._textureslots.length; i++) this._textureslots[i] = null;

        this.pushShader(this._simpleShader);

        this._frameStarted = true;

        if (this._onetimeCallbacks.length > 0)
        {
            for (let i = 0; i < this._onetimeCallbacks.length; i++) this._onetimeCallbacks[i]();
            this._onetimeCallbacks.length = 0;
        }

        for (let i = 0; i < this._textureslots.length; i++)
        {
            this.gl.activeTexture(this.gl.TEXTURE0 + i);
            this.gl.bindTexture(this.gl.TEXTURE_2D, null);
            this._textureslots[i] = null;
        }

        this.emitEvent("beginFrame");
    }

    renderEnd(cgl)
    {
        this._endMatrixStacks();

        this.popDepthTest();
        this.popDepthWrite();
        this.popDepthFunc();
        this.popCullFaceFacing();
        this.popCullFace();
        this.popBlend();
        this.popBlendMode();

        cgl.endFrame();

        this.emitEvent("endFrame");
    }

    getTexture(slot)
    {
        return this._textureslots[slot];
    }

    hasFrameStarted()
    {
        return this._frameStarted;
    }

    /**
     * log warning to console if the rendering of one frame has not been started / handy to check for async problems
     * @function checkFrameStarted
     * @memberof Context
     * @param string
     * @instance
     */
    checkFrameStarted(string)
    {
        if (!this._frameStarted)
        {
            this._log.warn("frame not started " + string);
            this.patch.printTriggerStack();
        }
    }


    setTexture(slot, t, type)
    {
        this.checkFrameStarted("cgl setTexture");

        if (t === null) t = CGL.Texture.getEmptyTexture(this).tex;

        if (this._textureslots[slot] != t)
        {
            this.gl.activeTexture(this.gl.TEXTURE0 + slot);
            this.gl.bindTexture(type || this.gl.TEXTURE_2D, t);
            this._textureslots[slot] = t;
        }


        return true;
    }

    fullScreen()
    {
        if (this.canvas.requestFullscreen) this.canvas.requestFullscreen();
        else if (this.canvas.mozRequestFullScreen) this.canvas.mozRequestFullScreen();
        else if (this.canvas.webkitRequestFullscreen) this.canvas.webkitRequestFullscreen();
        else if (this.canvas.msRequestFullscreen) this.canvas.msRequestFullscreen();
    }


    printError(str)
    {
        if (!this.checkGlErrors) return;
        let found = false;
        let error = this.gl.getError();

        if (error != this.gl.NO_ERROR)
        {
            let errStr = "";
            if (error == this.gl.OUT_OF_MEMORY) errStr = "OUT_OF_MEMORY";
            if (error == this.gl.INVALID_ENUM) errStr = "INVALID_ENUM";
            if (error == this.gl.INVALID_OPERATION) errStr = "INVALID_OPERATION";
            if (error == this.gl.INVALID_FRAMEBUFFER_OPERATION) errStr = "INVALID_FRAMEBUFFER_OPERATION";
            if (error == this.gl.INVALID_VALUE) errStr = "INVALID_VALUE";
            if (error == this.gl.CONTEXT_LOST_WEBGL)
            {
                this.aborted = true;
                errStr = "CONTEXT_LOST_WEBGL";
            }
            if (error == this.gl.NO_ERROR) errStr = "NO_ERROR";

            found = true;


            this._log.warn("gl error [" + this.canvas.id + "]: ", str, error, errStr);

            if (this.canvas.id.contains("glGuiCanvas"))
                if (!this._loggedGlError)
                {
                    this.patch.printTriggerStack();
                    this._log.stack("glerror");
                    this._loggedGlError = true;
                }
        }
        error = this.gl.getError();

        return found;
    }

    saveScreenshot(filename, cb, pw, ph, noclearalpha)
    {
        this.patch.renderOneFrame();

        let w = this.canvas.clientWidth * this.pixelDensity;
        let h = this.canvas.clientHeight * this.pixelDensity;

        if (pw)
        {
            this.canvas.width = pw;
            w = pw;
        }
        if (ph)
        {
            this.canvas.height = ph;
            h = ph;
        }

        function padLeft(nr, n, str)
        {
            return Array(n - String(nr).length + 1).join(str || "0") + nr;
        }

        const d = new Date();

        const dateStr = "".concat(String(d.getFullYear()) + String(d.getMonth() + 1) + String(d.getDate()), "_").concat(padLeft(d.getHours(), 2)).concat(padLeft(d.getMinutes(), 2)).concat(padLeft(d.getSeconds(), 2));

        if (!filename) filename = "cables_" + dateStr + ".png";
        else filename += ".png";

        this.patch.cgl.screenShot(function (blob)
        {
            this.canvas.width = w;
            this.canvas.height = h;

            if (blob)
            {
                const anchor = document.createElement("a");

                anchor.download = filename;
                anchor.href = URL.createObjectURL(blob);

                setTimeout(function ()
                {
                    anchor.click();
                    if (cb) cb(blob);
                }, 100);
            }
            else
            {
                this._log.log("screenshot: no blob");
            }
        }.bind(this), noclearalpha);
    }

    _dispose()
    {
        this._simpleShader.dispose();
        this.gl = null;
    }
}


Context.prototype.popShader = Context.prototype.setPreviousShader;
Context.prototype.setShader = Context.prototype.pushShader;

/**
 * execute the callback next frame, once
 * @function addNextFrameOnceCallback
 * @memberof Context
 * @instance
 * @param {function} cb
 */
Context.prototype.addNextFrameOnceCallback = function (cb)
{
    if (cb && this._onetimeCallbacks.indexOf(cb) == -1) this._onetimeCallbacks.push(cb);
};

// state depthtest

/**
 * push depth testing enabled state
 * @function pushDepthTest
 * @param {Boolean} enabled
 * @memberof Context
 * @instance
 */
Context.prototype._stackDepthTest = [];
Context.prototype.pushDepthTest = function (b)
{
    this._stackDepthTest.push(b);
    if (!b) this.gl.disable(this.gl.DEPTH_TEST);
    else this.gl.enable(this.gl.DEPTH_TEST);
};
/**
 * current state of depth testing
 * @function stateCullFace
 * @returns {Boolean} enabled
 * @memberof Context
 * @instance
 */
Context.prototype.stateDepthTest = function ()
{
    return this._stackDepthTest[this._stackDepthTest.length - 1];
};

/**
 * pop depth testing state
 * @function popCullFace
 * @memberof Context
 * @instance
 */
Context.prototype.popDepthTest = function ()
{
    this._stackDepthTest.pop();

    if (!this._stackDepthTest[this._stackDepthTest.length - 1]) this.gl.disable(this.gl.DEPTH_TEST);
    else this.gl.enable(this.gl.DEPTH_TEST);
};

// --------------------------------------
// state depthwrite

/**
 * push depth write enabled state
 * @function pushDepthTest
 * @param {Boolean} enabled
 * @memberof Context
 * @instance
 */
Context.prototype._stackDepthWrite = [];
Context.prototype.pushDepthWrite = function (b)
{
    b = b || false;
    this._stackDepthWrite.push(b);
    this.gl.depthMask(b);
};

/**
 * current state of depth writing
 * @function stateDepthWrite
 * @returns {Boolean} enabled
 * @memberof Context
 * @instance
 */
Context.prototype.stateDepthWrite = function ()
{
    return this._stackDepthWrite[this._stackDepthWrite.length - 1];
};

/**
 * pop depth writing state
 * @function popDepthWrite
 * @memberof Context
 * @instance
 */
Context.prototype.popDepthWrite = function ()
{
    this._stackDepthWrite.pop();
    this.gl.depthMask(this._stackDepthWrite[this._stackDepthWrite.length - 1] || false);
};


// --------------------------------------
// state CullFace

Context.prototype._stackCullFace = [];

/**
 * push face culling face enabled state
 * @function pushCullFace
 * @param {Boolean} b enabled
 * @memberof Context
 * @instance
 */
Context.prototype.pushCullFace = function (b)
{
    this._stackCullFace.push(b);

    if (b) this.gl.enable(this.gl.CULL_FACE);
    else this.gl.disable(this.gl.CULL_FACE);
};

/**
 * current state of face culling
 * @function stateCullFace
 * @returns {Boolean} enabled
 * @memberof Context
 * @instance
 */
Context.prototype.stateCullFace = function ()
{
    return this._stackCullFace[this._stackCullFace.length - 1];
};

/**
 * pop face culling enabled state
 * @function popCullFace
 * @memberof Context
 * @instance
 */
Context.prototype.popCullFace = function ()
{
    this._stackCullFace.pop();

    if (this._stackCullFace[this._stackCullFace.length - 1]) this.gl.enable(this.gl.CULL_FACE);
    else this.gl.disable(this.gl.CULL_FACE);
};


// --------------------------------------
// state CullFace Facing


/**
 * push face culling face side
 * @function pushCullFaceFacing
 * @param {Number} cgl.gl.FRONT_AND_BACK, cgl.gl.BACK or cgl.gl.FRONT
 * @memberof Context
 * @instance
 */
Context.prototype._stackCullFaceFacing = [];
Context.prototype.pushCullFaceFacing = function (b)
{
    this._stackCullFaceFacing.push(b);
    this.gl.cullFace(this._stackCullFaceFacing[this._stackCullFaceFacing.length - 1]);
};

/**
 * current state of face culling side
 * @function stateCullFaceFacing
 * @returns {Boolean} enabled
 * @memberof Context
 * @instance
 */
Context.prototype.stateCullFaceFacing = function ()
{
    return this._stackCullFaceFacing[this._stackCullFaceFacing.length - 1];
};

/**
 * pop face culling face side
 * @function popCullFaceFacing
 * @memberof Context
 * @instance
 */
Context.prototype.popCullFaceFacing = function ()
{
    this._stackCullFaceFacing.pop();
    if (this._stackCullFaceFacing.length > 0) this.gl.cullFace(this._stackCullFaceFacing[this._stackCullFaceFacing.length - 1]);
};


// --------------------------------------
// state depthfunc

Context.prototype._stackDepthFunc = [];

/**
 * enable / disable depth testing
 * like `gl.depthFunc(boolean);`
 * @function pushDepthFunc
 * @memberof Context
 * @instance
 * @param {Boolean} f depthtesting
 */
Context.prototype.pushDepthFunc = function (f)
{
    this._stackDepthFunc.push(f);
    this.gl.depthFunc(f);
};

/**
 * current state of blend
 * @function stateDepthFunc
 * @memberof Context
 * @instance
 * @returns {Boolean} depth testing enabled/disabled
 */
Context.prototype.stateDepthFunc = function ()
{
    if (this._stackDepthFunc.length > 0) return this._stackDepthFunc[this._stackDepthFunc.length - 1];
    return false;
};

/**
 * pop depth testing and set the previous state
 * @function popDepthFunc
 * @memberof Context
 * @instance
 */
Context.prototype.popDepthFunc = function ()
{
    this._stackDepthFunc.pop();
    if (this._stackDepthFunc.length > 0) this.gl.depthFunc(this._stackDepthFunc[this._stackDepthFunc.length - 1]);
};

// --------------------------------------
// state blending

Context.prototype._stackBlend = [];

/**
 * enable / disable blend
 * like gl.enable(gl.BLEND); / gl.disable(gl.BLEND);
 * @function pushBlend
 * @memberof Context
 * @instance
 * @param {boolean} b blending
 */
Context.prototype.pushBlend = function (b)
{
    this._stackBlend.push(b);
    if (!b) this.gl.disable(this.gl.BLEND);
    else this.gl.enable(this.gl.BLEND);
};

/**
 * pop blend state and set the previous state
 * @function popBlend
 * @memberof Context
 * @instance
 */
Context.prototype.popBlend = function ()
{
    this._stackBlend.pop();

    if (!this._stackBlend[this._stackBlend.length - 1]) this.gl.disable(this.gl.BLEND);
    else this.gl.enable(this.gl.BLEND);
};

/**
 * current state of blend
 * @function stateBlend
 * @returns {boolean} blending enabled/disabled
 * @memberof Context
 * @instance
 */
Context.prototype.stateBlend = function ()
{
    return this._stackBlend[this._stackBlend.length - 1];
};

export const BLENDS = {
    "BLEND_NONE": 0,
    "BLEND_NORMAL": 1,
    "BLEND_ADD": 2,
    "BLEND_SUB": 3,
    "BLEND_MUL": 4,
};

Context.prototype._stackBlendMode = [];
Context.prototype._stackBlendModePremul = [];

/**
 * push and switch to predefined blendmode (CONSTANTS.BLEND_MODES.BLEND_NONE,CONSTANTS.BLEND_MODES.BLEND_NORMAL,CONSTANTS.BLEND_MODES.BLEND_ADD,CONSTANTS.BLEND_MODES.BLEND_SUB,CONSTANTS.BLEND_MODES.BLEND_MUL)
 * @function pushBlendMode
 * @memberof Context
 * @instance
 * @param {Number} blendMode
 * @param {Boolean} premul premultiplied mode
 */
Context.prototype.pushBlendMode = function (blendMode, premul)
{
    this._stackBlendMode.push(blendMode);
    this._stackBlendModePremul.push(premul);

    const n = this._stackBlendMode.length - 1;

    this.pushBlend(this._stackBlendMode[n] !== CONSTANTS.BLEND_MODES.BLEND_NONE);
    this._setBlendMode(this._stackBlendMode[n], this._stackBlendModePremul[n]);
};

/**
 * pop predefined blendmode / switch back to previous blendmode
 * @function popBlendMode
 * @memberof Context
 * @instance
 */
Context.prototype.popBlendMode = function ()
{
    this._stackBlendMode.pop();
    this._stackBlendModePremul.pop();

    const n = this._stackBlendMode.length - 1;

    this.popBlend(this._stackBlendMode[n] !== CONSTANTS.BLEND_MODES.BLEND_NONE);

    if (n >= 0) this._setBlendMode(this._stackBlendMode[n], this._stackBlendModePremul[n]);
};


// --------------------------------------
// state stencil

Context.prototype._stackStencil = [];

/**
 * enable / disable stencil testing

* @function pushStencil
 * @memberof Context
 * @instance
 * @param {Boolean} b enable
 */
Context.prototype.pushStencil = function (b)
{
    this._stackStencil.push(b);
    if (!b) this.gl.disable(this.gl.STENCIL_TEST);
    else this.gl.enable(this.gl.STENCIL_TEST);
};

/**
 * pop stencil test state and set the previous state
 * @function popStencil
 * @memberof Context
 * @instance
 */
Context.prototype.popStencil = function ()
{
    this._stackStencil.pop();

    if (!this._stackStencil[this._stackStencil.length - 1]) this.gl.disable(this.gl.STENCIL_TEST);
    else this.gl.enable(this.gl.STENCIL_TEST);
};

// --------------------------------------


Context.prototype.glGetAttribLocation = function (prog, name)
{
    const l = this.gl.getAttribLocation(prog, name);
    // if (l == -1)
    // {
    //     this._log.warn("get attr loc -1 ", name);
    // }
    return l;
};


/**
 * should an op now draw helpermeshes
 * @function shouldDrawHelpers
 * @memberof Context
 * @param op
 * @instance
 */
Context.prototype.shouldDrawHelpers = function (op)
{
    if (this.frameStore.shadowPass) return false;
    if (!op.patch.isEditorMode()) return false;

    // const fb = this.getCurrentFrameBuffer();
    // if (fb && fb.getWidth)
    // {
    //     const fbshould = this.canvasWidth / this.canvasHeight == fb.getWidth() / fb.getHeight();
    //     if (!fbshould) return false;
    // }

    return gui.shouldDrawOverlay;// || (CABLES.UI.renderHelperCurrent && op.isCurrentUiOp());
};

Context.prototype._setBlendMode = function (blendMode, premul)
{
    const gl = this.gl;

    if (blendMode == CONSTANTS.BLEND_MODES.BLEND_NONE)
    {
        // this.gl.disable(this.gl.BLEND);
    }
    else if (blendMode == CONSTANTS.BLEND_MODES.BLEND_ADD)
    {
        if (premul)
        {
            gl.blendEquationSeparate(gl.FUNC_ADD, gl.FUNC_ADD);
            gl.blendFuncSeparate(gl.ONE, gl.ONE, gl.ONE, gl.ONE);
        }
        else
        {
            gl.blendEquation(gl.FUNC_ADD);
            gl.blendFunc(gl.SRC_ALPHA, gl.ONE);
        }
    }
    else if (blendMode == CONSTANTS.BLEND_MODES.BLEND_SUB)
    {
        if (premul)
        {
            gl.blendEquationSeparate(gl.FUNC_ADD, gl.FUNC_ADD);
            gl.blendFuncSeparate(gl.ZERO, gl.ZERO, gl.ONE_MINUS_SRC_COLOR, gl.ONE_MINUS_SRC_ALPHA);
        }
        else
        {
            gl.blendEquation(gl.FUNC_ADD);
            gl.blendFunc(gl.ZERO, gl.ONE_MINUS_SRC_COLOR);
        }
    }
    else if (blendMode == CONSTANTS.BLEND_MODES.BLEND_MUL)
    {
        if (premul)
        {
            gl.blendEquationSeparate(gl.FUNC_ADD, gl.FUNC_ADD);
            gl.blendFuncSeparate(gl.ZERO, gl.SRC_COLOR, gl.ZERO, gl.SRC_ALPHA);
        }
        else
        {
            gl.blendEquation(gl.FUNC_ADD);
            gl.blendFunc(gl.ZERO, gl.SRC_COLOR);
        }
    }
    else if (blendMode == CONSTANTS.BLEND_MODES.BLEND_NORMAL)
    {
        if (premul)
        {
            gl.blendEquationSeparate(gl.FUNC_ADD, gl.FUNC_ADD);
            gl.blendFuncSeparate(gl.ONE, gl.ONE_MINUS_SRC_ALPHA, gl.ONE, gl.ONE_MINUS_SRC_ALPHA);
        }
        else
        {
            gl.blendEquationSeparate(gl.FUNC_ADD, gl.FUNC_ADD);
            gl.blendFuncSeparate(gl.SRC_ALPHA, gl.ONE_MINUS_SRC_ALPHA, gl.ONE, gl.ONE_MINUS_SRC_ALPHA);
        }
    }
    else
    {
        this._log.log("setblendmode: unknown blendmode");
    }
};

Context.prototype.createMesh = function (geom, options)
{
    if (CABLES.UTILS.isNumeric(options))options = { "glPrimitive": options }; // old constructor fallback...
    return new CGL.Mesh(this, geom, options);
};


/**
 * set cursor
 * @function setCursor
 * @memberof Context
 * @instance
 * @param {String} str css cursor string
 */
Context.prototype.setCursor = function (str)
{
    this._cursor = str;
};

/**
 * enable a webgl extension
 * @function enableExtension
 * @memberof Context
 * @instance
 * @param {String} name extension name
 * @returns {Object} extension object or null
 */
Context.prototype.enableExtension = function (name)
{
    if (!this.gl) return null;

    if (this._enabledExtensions.hasOwnProperty(name))
        return this._enabledExtensions[name];

    const o = this.gl.getExtension(name);
    this._enabledExtensions[name] = o;

    if (!o)
        this._log.warn("[cgl_state] extension not available " + name);
    // else
        // this._log.log("enabled extension", name);

    return o;
};

Context.prototype.checkTextureSize = function (x)
{
    x = x || 1;
    x = Math.floor(x);
    x = Math.min(x, this.maxTexSize);
    x = Math.max(x, 1);
    return x;
};


export { Context };