src/viewer/scene/model/dtx/triangles/renderers/DTXTrianglesNormalsRenderer.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();
const tempVec3b = math.vec3();
const tempVec3c = math.vec3();
const tempVec3d = math.vec3();
const tempMat4a = math.mat4();

/**
 * @private
 */
export class DTXTrianglesNormalsRenderer {

    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, dataTextureLayer, renderPass) {

        const model = dataTextureLayer.model;
        const scene = model.scene;
        const camera = scene.camera;
        const gl = scene.canvas.gl;
        const state = dataTextureLayer._state;
        const origin = dataTextureLayer._state.origin;
        const {position, rotationMatrix} = model;
        const viewMatrix = camera.viewMatrix;

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

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

        let rtcViewMatrix;
        let rtcCameraEye;

        const gotOrigin = (origin[0] !== 0 || origin[1] !== 0 || origin[2] !== 0);
        const gotPosition = (position[0] !== 0 || position[1] !== 0 || position[2] !== 0);
        if (gotOrigin || gotPosition) {
            const rtcOrigin = tempVec3a;
            if (gotOrigin) {
                const rotatedOrigin = tempVec3b;
                math.transformPoint3(rotationMatrix, origin, rotatedOrigin);
                rtcOrigin[0] = rotatedOrigin[0];
                rtcOrigin[1] = rotatedOrigin[1];
                rtcOrigin[2] = rotatedOrigin[2];
            } else {
                rtcOrigin[0] = 0;
                rtcOrigin[1] = 0;
                rtcOrigin[2] = 0;
            }
            rtcOrigin[0] += position[0];
            rtcOrigin[1] += position[1];
            rtcOrigin[2] += position[2];
            rtcViewMatrix = createRTCViewMat(viewMatrix, rtcOrigin, tempMat4a);
            rtcCameraEye = tempVec3c;
            rtcCameraEye[0] = camera.eye[0] - rtcOrigin[0];
            rtcCameraEye[1] = camera.eye[1] - rtcOrigin[1];
            rtcCameraEye[2] = camera.eye[2] - rtcOrigin[2];
        } else {
            rtcViewMatrix = viewMatrix;
            rtcCameraEye = camera.eye;
        }

        gl.uniform1i(this._uRenderPass, renderPass);

        gl.uniformMatrix4fv(this._uWorldMatrix, false, rotationMatrix);
        gl.uniformMatrix4fv(this._uViewMatrix, false, rtcViewMatrix);
        gl.uniformMatrix4fv(this._uProjMatrix, false, camera.projMatrix);

        gl.uniformMatrix4fv(this._uViewNormalMatrix, false, camera.viewNormalMatrix);
        gl.uniformMatrix4fv(this._uWorldNormalMatrix, false, model.worldNormalMatrix);

        const numAllocatedSectionPlanes = scene._sectionPlanesState.getNumAllocatedSectionPlanes();
        const numSectionPlanes = scene._sectionPlanesState.sectionPlanes.length;
        if (numAllocatedSectionPlanes > 0) {
            const sectionPlanes = scene._sectionPlanesState.sectionPlanes;
            const baseIndex = dataTextureLayer.layerIndex * numSectionPlanes;
            const renderFlags = model.renderFlags;
            for (let sectionPlaneIndex = 0; sectionPlaneIndex < numAllocatedSectionPlanes; sectionPlaneIndex++) {
                const sectionPlaneUniforms = this._uSectionPlanes[sectionPlaneIndex];
                if (sectionPlaneUniforms) {
                    if (sectionPlaneIndex < numSectionPlanes) {
                        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, model.matrix);
                                gl.uniform3fv(sectionPlaneUniforms.pos, rtcSectionPlanePos);
                            } else {
                                gl.uniform3fv(sectionPlaneUniforms.pos, sectionPlane.pos);
                            }
                            gl.uniform3fv(sectionPlaneUniforms.dir, sectionPlane.dir);
                        }
                    } else {
                        gl.uniform1i(sectionPlaneUniforms.active, 0);
                    }
                }
            }
        }

        gl.uniformMatrix4fv(this._uPositionsDecodeMatrix, false, dataTextureLayer._state.objectDecodeAndInstanceMatrix);

        this._aPosition.bindArrayBuffer(state.positionsBuf);
        this._aOffset.bindArrayBuffer(state.offsetsBuf);
        this._aNormal.bindArrayBuffer(state.normalsBuf);
        this._aColor.bindArrayBuffer(state.colorsBuf);// Needed for masking out transparent entities using alpha channel
        this._aFlags.bindArrayBuffer(state.flagsBuf);
        if (this._aFlags2) {
            this._aFlags2.bindArrayBuffer(state.flags2Buf);
        }
        state.indicesBuf.bind();

        gl.drawElements(gl.TRIANGLES, state.indicesBuf.numItems, state.indicesBuf.itemType, 0);
    }

    _allocate() {
        const scene = this._scene;
        const gl = scene.canvas.gl;
        this._program = new Program(gl, this._buildShader());
        if (this._program.errors) {
            this.errors = this._program.errors;
            return;
        }
        const program = this._program;
        this._uRenderPass = program.getLocation("renderPass");
        this._uPositionsDecodeMatrix = program.getLocation("objectDecodeAndInstanceMatrix");
        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 = [];
        for (let i = 0, len = scene._sectionPlanesState.getNumAllocatedSectionPlanes(); 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._aColor = program.getAttribute("color");
        this._aFlags = program.getAttribute("flags");
        if (this._aFlags2) { // Won't be in shader when not clipping
            this._aFlags2 = program.getAttribute("flags2");
        }
        if ( scene.logarithmicDepthBufferEnabled) {
            this._uLogDepthBufFC = program.getLocation("logDepthBufFC");
        }
    }

    _bindProgram() {
        const scene = this._scene;
        const gl = scene.canvas.gl;
        const project = scene.camera.project;
        this._program.bind();
        gl.uniformMatrix4fv(this._uProjMatrix, false, project.matrix);
        if ( scene.logarithmicDepthBufferEnabled) {
            const logDepthBufFC = 2.0 / (Math.log(project.far + 1.0) / Math.LN2);
            gl.uniform1f(this._uLogDepthBufFC, logDepthBufFC);
        }
    }

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

    _buildVertexShader() {
        const scene = this._scene;
        const clipping = scene._sectionPlanesState.getNumAllocatedSectionPlanes() > 0;
        const src = [];
        src.push("// Batched 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 vec3 normal;");
        src.push("attribute vec4 color;");
        src.push("attribute vec4 flags;");
        src.push("attribute vec4 flags2;");
        src.push("uniform mat4 worldMatrix;");
        src.push("uniform mat4 worldNormalMatrix;");
        src.push("uniform mat4 viewMatrix;");
        src.push("uniform mat4 projMatrix;");
        src.push("uniform mat4 viewNormalMatrix;");
        src.push("uniform mat4 objectDecodeAndInstanceMatrix;");
        if (scene.logarithmicDepthBufferEnabled) {
            src.push("uniform float logDepthBufFC;");
            if (WEBGL_INFO.SUPPORTED_EXTENSIONS["EXT_frag_depth"]) {
                src.push("out 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("out vec4 vWorldPosition;");
            src.push("out vec4 vFlags2;");
        }
        src.push("out vec3 vViewNormal;");
        src.push("void main(void) {");

        // flags.x = NOT_RENDERED | COLOR_OPAQUE | COLOR_TRANSPARENT
        // renderPass = COLOR_OPAQUE

        src.push(`if (int(flags.x) != renderPass) {`);
        src.push("      gl_Position = vec4(0.0, 0.0, 0.0, 0.0);");

        src.push("  } else {");
        src.push("      vec4 worldPosition = worldMatrix * (objectDecodeAndInstanceMatrix * vec4(position, 1.0)); ");
        if (scene.entityOffsetsEnabled) {
            src.push("      worldPosition.xyz = worldPosition.xyz + offset;");
        }
        src.push("      vec4 viewPosition   = viewMatrix * worldPosition; ");
        src.push("      vec4 worldNormal    = worldNormalMatrix * vec4(octDecode(normal.xy), 0.0); ");
        src.push("      vec3 viewNormal     = normalize((viewNormalMatrix * worldNormal).xyz);");
        if (clipping) {
            src.push("      vWorldPosition  = worldPosition;");
            src.push("      vFlags2         = flags2;");
        }
        src.push("      vViewNormal = viewNormal;");
        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 clipping = (scene._sectionPlanesState.getNumAllocatedSectionPlanes() > 0);
        const src = [];
        src.push("#version 300 es");
        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("in float isPerspective;");
            src.push("uniform float logDepthBufFC;");
            src.push("in float vFragDepth;");
        }

        if (clipping) {
            src.push("in vec4 vWorldPosition;");
            src.push("in vec4 vFlags2;");
            for (let i = 0; i < scene._sectionPlanesState.getNumAllocatedSectionPlanes(); i++) {
                src.push("uniform bool sectionPlaneActive" + i + ";");
                src.push("uniform vec3 sectionPlanePos" + i + ";");
                src.push("uniform vec3 sectionPlaneDir" + i + ";");
            }
        }
        src.push("in vec3 vViewNormal;");
        src.push("vec3 packNormalToRGB( const in vec3 normal ) {");
        src.push("    return normalize( normal ) * 0.5 + 0.5;");
        src.push("}");
        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 < scene._sectionPlanesState.getNumAllocatedSectionPlanes(); 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(packNormalToRGB(vViewNormal), 1.0); ");
        src.push("}");
        return src;
    }

    webglContextRestored() {
        this._program = null;
    }

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