src/viewer/scene/PerformanceModel/lib/layers/trianglesInstancing/renderers/TrianglesInstancingPickNormalsRenderer.js

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

const tempVec3a = math.vec3();

/**
 * @private
 */
class TrianglesInstancingPickNormalsRenderer {

    constructor(scene) {
        this._scene = scene;
        this._hash = this._getHash();
        this._allocate();
    }

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

    _getHash() {
        return this._scene._sectionPlanesState.getHash();
    }

    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 origin = instancingLayer._state.origin;

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

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

        // In practice, these binds will only happen once per frame
        // because we pick normals on a single previously-picked mesh

        gl.uniform1i(this._uRenderPass, renderPass);

        gl.uniform1i(this._uPickInvisible, frameCtx.pickInvisible);

        const pickViewMatrix = frameCtx.pickViewMatrix || camera.viewMatrix;
        const rtcPickViewMatrix = (origin) ? createRTCViewMat(pickViewMatrix, origin) : pickViewMatrix;

        gl.uniformMatrix4fv(this._uViewMatrix, false, rtcPickViewMatrix);
        gl.uniformMatrix4fv(this._uProjMatrix, false, frameCtx.pickProjMatrix);

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

        if (scene.logarithmicDepthBufferEnabled) {
            const logDepthBufFC = 2.0 / (Math.log(camera.project.far + 1.0) / Math.LN2); // TODO: Far from pick project matrix?
            gl.uniform1f(this._uLogDepthBufFC, logDepthBufFC);
        }

        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];
                if (sectionPlaneUniforms) {
                    const active = renderFlags.sectionPlanesActivePerLayer[baseIndex + sectionPlaneIndex];
                    gl.uniform1i(sectionPlaneUniforms.active, active ? 1 : 0);
                    if (active) {
                        const sectionPlane = sectionPlanes[sectionPlaneIndex];
                        if (origin) {
                            const rtcSectionPlanePos = getPlaneRTCPos(sectionPlane.dist, sectionPlane.dir, origin, tempVec3a);
                            gl.uniform3fv(sectionPlaneUniforms.pos, rtcSectionPlanePos);
                        } else {
                            gl.uniform3fv(sectionPlaneUniforms.pos, sectionPlane.pos);
                        }
                        gl.uniform3fv(sectionPlaneUniforms.dir, sectionPlane.dir);
                    }
                }
            }
        }

        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._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(gl.TRIANGLES, 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._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 sectionPlanesState = scene._sectionPlanesState;

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

        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._uPickInvisible = program.getLocation("pickInvisible");
        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._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._aOffset = program.getAttribute("offset");
        this._aNormal = program.getAttribute("normal");
        this._aFlags = program.getAttribute("flags");
        this._aFlags2 = program.getAttribute("flags2");

        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");

        if (scene.logarithmicDepthBufferEnabled) {
            this._uLogDepthBufFC = program.getLocation("logDepthBufFC");
        }
    }

    _bindProgram() {
        this._program.bind();
    }

    _buildShader() {
        return {
            vertex: this._buildVertexShader(),
            fragment: this._buildFragmentShader()
        };
    }

    _buildVertexShader() {
        const scene = this._scene;
        const sectionPlanesState = scene._sectionPlanesState;
        const clipping = sectionPlanesState.sectionPlanes.length > 0;
        const src = [];
        src.push("// Instancing geometry normals vertex shader");
        if (scene.logarithmicDepthBufferEnabled && WEBGL_INFO.SUPPORTED_EXTENSIONS["EXT_frag_depth"]) {
            src.push("#extension GL_EXT_frag_depth : enable");
        }
        src.push("uniform int renderPass;");
        src.push("attribute vec3 position;");
        if (scene.entityOffsetsEnabled) {
            src.push("attribute vec3 offset;");
        }
        src.push("attribute vec2 normal;");
        src.push("attribute vec4 flags;");
        src.push("attribute vec4 flags2;");
        src.push("attribute vec4 modelMatrixCol0;"); // Modeling matrix
        src.push("attribute vec4 modelMatrixCol1;");
        src.push("attribute vec4 modelMatrixCol2;");
        src.push("attribute vec4 modelNormalMatrixCol0;");
        src.push("attribute vec4 modelNormalMatrixCol1;");
        src.push("attribute vec4 modelNormalMatrixCol2;");
        src.push("uniform bool pickInvisible;");
        src.push("uniform mat4 worldMatrix;");
        src.push("uniform mat4 viewMatrix;");
        src.push("uniform mat4 projMatrix;");
        src.push("uniform mat4 positionsDecodeMatrix;")
        if (scene.logarithmicDepthBufferEnabled) {
            src.push("uniform float logDepthBufFC;");
            if (WEBGL_INFO.SUPPORTED_EXTENSIONS["EXT_frag_depth"]) {
                src.push("varying float vFragDepth;");
            }
            src.push("bool isPerspectiveMatrix(mat4 m) {");
            src.push("    return (m[2][3] == - 1.0);");
            src.push("}");
            src.push("varying float isPerspective;");
        }
        src.push("vec3 octDecode(vec2 oct) {");
        src.push("    vec3 v = vec3(oct.xy, 1.0 - abs(oct.x) - abs(oct.y));");
        src.push("    if (v.z < 0.0) {");
        src.push("        v.xy = (1.0 - abs(v.yx)) * vec2(v.x >= 0.0 ? 1.0 : -1.0, v.y >= 0.0 ? 1.0 : -1.0);");
        src.push("    }");
        src.push("    return normalize(v);");
        src.push("}");
        if (clipping) {
            src.push("varying vec4 vWorldPosition;");
            src.push("varying vec4 vFlags2;");
        }
        src.push("varying vec3 vWorldNormal;");
        src.push("void main(void) {");

        // flags.w = NOT_RENDERED | PICK
        // renderPass = PICK

        src.push(`if (int(flags.w) != renderPass) {`);
        src.push("   gl_Position = vec4(0.0, 0.0, 0.0, 0.0);"); // Cull vertex

        src.push("} else {");
        src.push("  vec4 worldPosition = positionsDecodeMatrix * vec4(position, 1.0); ");
        src.push("  worldPosition = worldMatrix * vec4(dot(worldPosition, modelMatrixCol0), dot(worldPosition, modelMatrixCol1), dot(worldPosition, modelMatrixCol2), 1.0);");
        if (scene.entityOffsetsEnabled) {
            src.push("      worldPosition.xyz = worldPosition.xyz + offset;");
        }
        src.push("  vec4 viewPosition  = viewMatrix * worldPosition; ");
        src.push("  vec4 modelNormal = vec4(octDecode(normal.xy), 0.0); ");
        src.push("  vec3 worldNormal = vec3(dot(modelNormal, modelNormalMatrixCol0), dot(modelNormal, modelNormalMatrixCol1), dot(modelNormal, modelNormalMatrixCol2));");
        src.push("  vWorldNormal = worldNormal;");
        if (clipping) {
            src.push("  vWorldPosition = worldPosition;");
        }
        src.push("vec4 clipPos = projMatrix * viewPosition;");
        if (scene.logarithmicDepthBufferEnabled) {
            if (WEBGL_INFO.SUPPORTED_EXTENSIONS["EXT_frag_depth"]) {
                src.push("vFragDepth = 1.0 + clipPos.w;");
            } else {
                src.push("clipPos.z = log2( max( 1e-6, clipPos.w + 1.0 ) ) * logDepthBufFC - 1.0;");
                src.push("clipPos.z *= clipPos.w;");
            }
            src.push("isPerspective = float (isPerspectiveMatrix(projMatrix));");
        }
        src.push("gl_Position = clipPos;");
        src.push("}");
        src.push("}");
        return src;
    }

    _buildFragmentShader() {
        const scene = this._scene;
        const sectionPlanesState = scene._sectionPlanesState;
        const clipping = sectionPlanesState.sectionPlanes.length > 0;
        const src = [];
        src.push("// Batched geometry normals fragment shader");

        if (scene.logarithmicDepthBufferEnabled && WEBGL_INFO.SUPPORTED_EXTENSIONS["EXT_frag_depth"]) {
            src.push("#extension GL_EXT_frag_depth : enable");
        }

        src.push("#ifdef GL_FRAGMENT_PRECISION_HIGH");
        src.push("precision highp float;");
        src.push("precision highp int;");
        src.push("#else");
        src.push("precision mediump float;");
        src.push("precision mediump int;");
        src.push("#endif");

        if (scene.logarithmicDepthBufferEnabled && WEBGL_INFO.SUPPORTED_EXTENSIONS["EXT_frag_depth"]) {
            src.push("varying float isPerspective;");
            src.push("uniform float logDepthBufFC;");
            src.push("varying float vFragDepth;");
        }

        if (clipping) {
            src.push("varying vec4 vWorldPosition;");
            src.push("varying vec4 vFlags2;");
            for (let i = 0; i < sectionPlanesState.sectionPlanes.length; i++) {
                src.push("uniform bool sectionPlaneActive" + i + ";");
                src.push("uniform vec3 sectionPlanePos" + i + ";");
                src.push("uniform vec3 sectionPlaneDir" + i + ";");
            }
        }
        src.push("varying vec3 vWorldNormal;");
        src.push("void main(void) {");
        if (clipping) {
            src.push("  bool clippable = (float(vFlags2.x) > 0.0);");
            src.push("  if (clippable) {");
            src.push("  float dist = 0.0;");
            for (var i = 0; i < sectionPlanesState.sectionPlanes.length; i++) {
                src.push("if (sectionPlaneActive" + i + ") {");
                src.push("   dist += clamp(dot(-sectionPlaneDir" + i + ".xyz, vWorldPosition.xyz - sectionPlanePos" + i + ".xyz), 0.0, 1000.0);");
                src.push("}");
            }
            src.push("if (dist > 0.0) { discard; }");
            src.push("}");
        }
        if (scene.logarithmicDepthBufferEnabled && WEBGL_INFO.SUPPORTED_EXTENSIONS["EXT_frag_depth"]) {
            src.push("    gl_FragDepthEXT = isPerspective == 0.0 ? gl_FragCoord.z : log2( vFragDepth ) * logDepthBufFC * 0.5;");
        }
        src.push("    gl_FragColor = vec4((vWorldNormal * 0.5) + 0.5, 1.0);");
        src.push("}");
        return src;
    }

    webglContextRestored() {
        this._program = null;
    }

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

export {TrianglesInstancingPickNormalsRenderer};