src/viewer/scene/PerformanceModel/lib/instancing/draw/InstancingDrawRenderer.js

import {Program} from "../../../../webgl/Program.js";
import {InstancingDrawShaderSource} from "./InstancingDrawShaderSource.js";
import {math} from "../../../../math/math.js";
import {createRTCViewMat, getPlaneRTCPos} from "../../../../math/rtcCoords.js";

const tempVec4 = math.vec4();
const tempVec3a = math.vec3();

const tempMat4a = math.mat4();
const tempMat4b = math.mat4();


/**
 * @private
 */
class InstancingDrawRenderer {

    constructor(scene, withSAO) {
        this._scene = scene;
        this._withSAO = withSAO;
        this._hash = this._getHash();
        this._shaderSource = new InstancingDrawShaderSource(this._scene, this._withSAO);
        this._allocate();
    }

    getValid() {
        return this._hash === this._getHash();
    };

    _getHash() {
        const scene = this._scene;
        return [scene._lightsState.getHash(), scene._sectionPlanesState.getHash(), (this._withSAO ? "sao" : "nosao")].join(";");
    }

    drawLayer(frameCtx, instancingLayer, renderPass) {

        const model = instancingLayer.model;
        const scene = model.scene;
        const camera = scene.camera;
        const gl = scene.canvas.gl;
        const state = instancingLayer._state;
        const instanceExt = this._instanceExt;
        const rtcCenter = instancingLayer._state.rtcCenter;

        if (!this._program) {
            this._allocate();
            if (this.errors) {
                return;
            }
        }

        if (frameCtx.lastProgramId !== this._program.id) {
            frameCtx.lastProgramId = this._program.id;
            this._bindProgram(frameCtx);
        }

        gl.uniformMatrix4fv(this._uViewMatrix, false, (rtcCenter) ? createRTCViewMat(camera.viewMatrix, rtcCenter) : camera.viewMatrix);
        gl.uniformMatrix4fv(this._uViewNormalMatrix, false, camera.viewNormalMatrix);

        gl.uniformMatrix4fv(this._uWorldMatrix, false, model.worldMatrix);
        gl.uniformMatrix4fv(this._uWorldNormalMatrix, false, model.worldNormalMatrix);

        const numSectionPlanes = scene._sectionPlanesState.sectionPlanes.length;
        if (numSectionPlanes > 0) {
            const sectionPlanes = scene._sectionPlanesState.sectionPlanes;
            const baseIndex = instancingLayer.layerIndex * numSectionPlanes;
            const renderFlags = model.renderFlags;
            for (let sectionPlaneIndex = 0; sectionPlaneIndex < numSectionPlanes; sectionPlaneIndex++) {
                const sectionPlaneUniforms = this._uSectionPlanes[sectionPlaneIndex];
                const active = renderFlags.sectionPlanesActivePerLayer[baseIndex + sectionPlaneIndex];
                gl.uniform1i(sectionPlaneUniforms.active, active ? 1 : 0);
                if (active) {
                    const sectionPlane = sectionPlanes[sectionPlaneIndex];
                    if (rtcCenter) {
                        const rtcSectionPlanePos = getPlaneRTCPos(sectionPlane.dist, sectionPlane.dir, rtcCenter, tempVec3a);
                        gl.uniform3fv(sectionPlaneUniforms.pos, rtcSectionPlanePos);
                    } else {
                        gl.uniform3fv(sectionPlaneUniforms.pos, sectionPlane.pos);
                    }
                    gl.uniform3fv(sectionPlaneUniforms.dir, sectionPlane.dir);
                }
            }
        }

        gl.uniform1i(this._uRenderPass, renderPass);

        gl.uniformMatrix4fv(this._uPositionsDecodeMatrix, false, instancingLayer._state.positionsDecodeMatrix);

        this._aModelMatrixCol0.bindArrayBuffer(state.modelMatrixCol0Buf);
        this._aModelMatrixCol1.bindArrayBuffer(state.modelMatrixCol1Buf);
        this._aModelMatrixCol2.bindArrayBuffer(state.modelMatrixCol2Buf);

        instanceExt.vertexAttribDivisorANGLE(this._aModelMatrixCol0.location, 1);
        instanceExt.vertexAttribDivisorANGLE(this._aModelMatrixCol1.location, 1);
        instanceExt.vertexAttribDivisorANGLE(this._aModelMatrixCol2.location, 1);

        this._aModelNormalMatrixCol0.bindArrayBuffer(state.modelNormalMatrixCol0Buf);
        this._aModelNormalMatrixCol1.bindArrayBuffer(state.modelNormalMatrixCol1Buf);
        this._aModelNormalMatrixCol2.bindArrayBuffer(state.modelNormalMatrixCol2Buf);

        instanceExt.vertexAttribDivisorANGLE(this._aModelNormalMatrixCol0.location, 1);
        instanceExt.vertexAttribDivisorANGLE(this._aModelNormalMatrixCol1.location, 1);
        instanceExt.vertexAttribDivisorANGLE(this._aModelNormalMatrixCol2.location, 1);

        this._aPosition.bindArrayBuffer(state.positionsBuf);
        this._aNormal.bindArrayBuffer(state.normalsBuf);

        this._aColor.bindArrayBuffer(state.colorsBuf);
        instanceExt.vertexAttribDivisorANGLE(this._aColor.location, 1);

        this._aFlags.bindArrayBuffer(state.flagsBuf);
        instanceExt.vertexAttribDivisorANGLE(this._aFlags.location, 1);

        if (this._aFlags2) {
            this._aFlags2.bindArrayBuffer(state.flags2Buf);
            instanceExt.vertexAttribDivisorANGLE(this._aFlags2.location, 1);
        }

        if (this._aOffset) {
            this._aOffset.bindArrayBuffer(state.offsetsBuf);
            instanceExt.vertexAttribDivisorANGLE(this._aOffset.location, 1);
        }

        state.indicesBuf.bind();

        instanceExt.drawElementsInstancedANGLE(state.primitive, state.indicesBuf.numItems, state.indicesBuf.itemType, 0, state.numInstances);

        instanceExt.vertexAttribDivisorANGLE(this._aModelMatrixCol0.location, 0);
        instanceExt.vertexAttribDivisorANGLE(this._aModelMatrixCol1.location, 0);
        instanceExt.vertexAttribDivisorANGLE(this._aModelMatrixCol2.location, 0);
        instanceExt.vertexAttribDivisorANGLE(this._aModelNormalMatrixCol0.location, 0);
        instanceExt.vertexAttribDivisorANGLE(this._aModelNormalMatrixCol1.location, 0);
        instanceExt.vertexAttribDivisorANGLE(this._aModelNormalMatrixCol2.location, 0);
        instanceExt.vertexAttribDivisorANGLE(this._aColor.location, 0);
        instanceExt.vertexAttribDivisorANGLE(this._aFlags.location, 0);

        if (this._aFlags2) { // Won't be in shader when not clipping
            instanceExt.vertexAttribDivisorANGLE(this._aFlags2.location, 0);
        }

        if (this._aOffset) {
            instanceExt.vertexAttribDivisorANGLE(this._aOffset.location, 0);
        }
    }

    _allocate() {
        const scene = this._scene;
        const gl = scene.canvas.gl;
        const lightsState = scene._lightsState;
        const sectionPlanesState = scene._sectionPlanesState;

        this._program = new Program(gl, this._shaderSource);

        if (this._program.errors) {
            this.errors = this._program.errors;
            return;
        }

        this._instanceExt = gl.getExtension("ANGLE_instanced_arrays");

        const program = this._program;
        this._uRenderPass = program.getLocation("renderPass");

        this._uPositionsDecodeMatrix = program.getLocation("positionsDecodeMatrix");

        this._uWorldMatrix = program.getLocation("worldMatrix");
        this._uWorldNormalMatrix = program.getLocation("worldNormalMatrix");

        this._uViewMatrix = program.getLocation("viewMatrix");
        this._uViewNormalMatrix = program.getLocation("viewNormalMatrix");
        this._uProjMatrix = program.getLocation("projMatrix");

        this._uLightAmbient = [];
        this._uLightColor = [];
        this._uLightDir = [];
        this._uLightPos = [];
        this._uLightAttenuation = [];
        const lights = lightsState.lights;
        let light;

        for (var i = 0, len = lights.length; i < len; i++) {
            light = lights[i];
            switch (light.type) {
                case "ambient":
                    this._uLightAmbient[i] = program.getLocation("lightAmbient");
                    break;
                case "dir":
                    this._uLightColor[i] = program.getLocation("lightColor" + i);
                    this._uLightPos[i] = null;
                    this._uLightDir[i] = program.getLocation("lightDir" + i);
                    break;
                case "point":
                    this._uLightColor[i] = program.getLocation("lightColor" + i);
                    this._uLightPos[i] = program.getLocation("lightPos" + i);
                    this._uLightDir[i] = null;
                    this._uLightAttenuation[i] = program.getLocation("lightAttenuation" + i);
                    break;
                case "spot":
                    this._uLightColor[i] = program.getLocation("lightColor" + i);
                    this._uLightPos[i] = program.getLocation("lightPos" + i);
                    this._uLightDir[i] = program.getLocation("lightDir" + i);
                    this._uLightAttenuation[i] = program.getLocation("lightAttenuation" + i);
                    break;
            }
        }

        this._uSectionPlanes = [];
        const clips = sectionPlanesState.sectionPlanes;
        for (let i = 0, len = clips.length; i < len; i++) {
            this._uSectionPlanes.push({
                active: program.getLocation("sectionPlaneActive" + i),
                pos: program.getLocation("sectionPlanePos" + i),
                dir: program.getLocation("sectionPlaneDir" + i)
            });
        }

        this._aPosition = program.getAttribute("position");
        this._aNormal = program.getAttribute("normal");
        this._aColor = program.getAttribute("color");
        this._aFlags = program.getAttribute("flags");
        this._aFlags2 = program.getAttribute("flags2");
        this._aOffset = program.getAttribute("offset");

        this._aModelMatrixCol0 = program.getAttribute("modelMatrixCol0");
        this._aModelMatrixCol1 = program.getAttribute("modelMatrixCol1");
        this._aModelMatrixCol2 = program.getAttribute("modelMatrixCol2");

        this._aModelNormalMatrixCol0 = program.getAttribute("modelNormalMatrixCol0");
        this._aModelNormalMatrixCol1 = program.getAttribute("modelNormalMatrixCol1");
        this._aModelNormalMatrixCol2 = program.getAttribute("modelNormalMatrixCol2");

        this._uOcclusionTexture = "uOcclusionTexture";
        this._uSAOParams = program.getLocation("uSAOParams");
    }

    _bindProgram(frameCtx) {
        const scene = this._scene;
        const gl = scene.canvas.gl;
        const program = this._program;
        const lightsState = scene._lightsState;
        const lights = lightsState.lights;
        let light;
        program.bind();
        const camera = scene.camera;
        gl.uniformMatrix4fv(this._uProjMatrix, false, camera._project._state.matrix);
        for (let i = 0, len = lights.length; i < len; i++) {
            light = lights[i];
            if (this._uLightAmbient[i]) {
                gl.uniform4f(this._uLightAmbient[i], light.color[0], light.color[1], light.color[2], light.intensity);
            } else {
                if (this._uLightColor[i]) {
                    gl.uniform4f(this._uLightColor[i], light.color[0], light.color[1], light.color[2], light.intensity);
                }
                if (this._uLightPos[i]) {
                    gl.uniform3fv(this._uLightPos[i], light.pos);
                    if (this._uLightAttenuation[i]) {
                        gl.uniform1f(this._uLightAttenuation[i], light.attenuation);
                    }
                }
                if (this._uLightDir[i]) {
                    gl.uniform3fv(this._uLightDir[i], light.dir);
                }
            }
        }
        if (this._withSAO) {
            const sao = scene.sao;
            const saoEnabled = sao.possible;
            if (saoEnabled) {
                const viewportWidth = gl.drawingBufferWidth;
                const viewportHeight = gl.drawingBufferHeight;
                tempVec4[0] = viewportWidth;
                tempVec4[1] = viewportHeight;
                tempVec4[2] = sao.blendCutoff;
                tempVec4[3] = sao.blendFactor;
                gl.uniform4fv(this._uSAOParams, tempVec4);
                this._program.bindTexture(this._uOcclusionTexture, frameCtx.occlusionTexture, 0);
            }
        }
    }

    webglContextRestored() {
        this._program = null;
    }

    destroy() {
        if (this._program) {
            this._program.destroy();
        }
        this._program = null;
    }
}

export {InstancingDrawRenderer};