@vrame/xeokit-sdk/src/viewer/scene/model/vbo/batching/triangles/renderers/TrianglesPickDepthRenderer.js

3D BIM IFC Viewer SDK for AEC engineering applications. Open Source JavaScript Toolkit based on pure WebGL for top performance, real-world coordinates and full double precision

import {TrianglesBatchingRenderer} from "./TrianglesBatchingRenderer.js";

/**
 * @private
 */
export class TrianglesPickDepthRenderer extends TrianglesBatchingRenderer {

    _buildVertexShader() {

        const scene = this._scene;
        const clipping = scene._sectionPlanesState.getNumAllocatedSectionPlanes() > 0;
        const src = [];
        src.push("#version 300 es");
        src.push("// Triangles batching pick depth vertex shader");

        

        src.push("uniform int renderPass;");

        src.push("in vec3 position;");
        if (scene.entityOffsetsEnabled) {
            src.push("in vec3 offset;");
        }
        src.push("in float flags;");

        src.push("uniform bool pickInvisible;");

        this._addMatricesUniformBlockLines(src);

        if (scene.logarithmicDepthBufferEnabled) {
            src.push("uniform float logDepthBufFC;");
            src.push("out float vFragDepth;");
            src.push("bool isPerspectiveMatrix(mat4 m) {");
            src.push("    return (m[2][3] == - 1.0);");
            src.push("}");
            src.push("out float isPerspective;");
        }

        if (clipping) {
            src.push("out vec4 vWorldPosition;");
            src.push("out float vFlags;");
        }

        this._addRemapClipPosLines(src);

        src.push("out vec4 vViewPosition;");
        src.push("void main(void) {");

        // pickFlag = NOT_RENDERED | PICK
        // renderPass = PICK

        src.push(`int pickFlag = int(flags) >> 12 & 0xF;`);
        src.push(`if (pickFlag != renderPass) {`);
        src.push("      gl_Position = vec4(0.0, 0.0, 0.0, 0.0);"); // Cull vertex
        src.push("  } else {");
        src.push("      vec4 worldPosition = worldMatrix * (positionsDecodeMatrix * vec4(position, 1.0)); ");
        if (scene.entityOffsetsEnabled) {
            src.push("      worldPosition.xyz = worldPosition.xyz + offset;");
        }
        src.push("      vec4 viewPosition  = viewMatrix * worldPosition; ");
        if (clipping) {
            src.push("      vWorldPosition = worldPosition;");
            src.push("      vFlags = flags;");
        }
        src.push("vViewPosition = viewPosition;");
        src.push("vec4 clipPos = projMatrix * viewPosition;");
        if (scene.logarithmicDepthBufferEnabled) {
           src.push("vFragDepth = 1.0 + clipPos.w;");
            src.push("isPerspective = float (isPerspectiveMatrix(projMatrix));");
        }
        src.push("gl_Position = remapClipPos(clipPos);");
        src.push("  }");
        src.push("}");
        return src;
    }

    _buildFragmentShader() {

        const scene = this._scene;
        const sectionPlanesState = scene._sectionPlanesState;
        const clipping = sectionPlanesState.getNumAllocatedSectionPlanes() > 0;
        const src = [];
        src.push("#version 300 es");
        src.push("// Triangles batching pick depth fragment shader");

        

        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) {
            src.push("in float isPerspective;");
            src.push("uniform float logDepthBufFC;");
            src.push("in float vFragDepth;");
        }

        src.push("uniform float pickZNear;");
        src.push("uniform float pickZFar;");

        if (clipping) {
            src.push("in vec4 vWorldPosition;");
            src.push("in float vFlags;");
            for (var i = 0; i < sectionPlanesState.getNumAllocatedSectionPlanes(); i++) {
                src.push("uniform bool sectionPlaneActive" + i + ";");
                src.push("uniform vec3 sectionPlanePos" + i + ";");
                src.push("uniform vec3 sectionPlaneDir" + i + ";");
            }
        }
        src.push("in vec4 vViewPosition;");
        src.push("vec4 packDepth(const in float depth) {");
        src.push("  const vec4 bitShift = vec4(256.0*256.0*256.0, 256.0*256.0, 256.0, 1.0);");
        src.push("  const vec4 bitMask  = vec4(0.0, 1.0/256.0, 1.0/256.0, 1.0/256.0);");
        src.push("  vec4 res = fract(depth * bitShift);");
        src.push("  res -= res.xxyz * bitMask;");
        src.push("  return res;");
        src.push("}");
        src.push("out vec4 outColor;");
        src.push("void main(void) {");
        if (clipping) {
            src.push("  bool clippable = (int(vFlags) >> 16 & 0xF) == 1;");
            src.push("  if (clippable) {");
            src.push("      float dist = 0.0;");
            for (let i = 0; i < 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) {
            src.push("    gl_FragDepth = isPerspective == 0.0 ? gl_FragCoord.z : log2( vFragDepth ) * logDepthBufFC * 0.5;");
        }
        src.push("    float zNormalizedDepth = abs((pickZNear + vViewPosition.z) / (pickZFar - pickZNear));");
        src.push("    outColor = packDepth(zNormalizedDepth); ");  // Must be linear depth
        src.push("}");
        return src;
    }
}