@vrame/xeokit-sdk/src/viewer/scene/model/vbo/batching/points/renderers/VBOBatchingPointsOcclusionRenderer.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 {VBOBatchingPointsRenderer} from "../VBOBatchingPointsRenderer.js";


/**
 * @private
 */
class VBOBatchingPointsOcclusionRenderer extends VBOBatchingPointsRenderer {
    _getHash() {
        return this._scene._sectionPlanesState.getHash() + (this._scene.pointsMaterial.hash);
    }

    _buildVertexShader() {
        const scene = this._scene;
        const clipping = scene._sectionPlanesState.getNumAllocatedSectionPlanes() > 0;
        const pointsMaterial = scene.pointsMaterial._state;
        const src = [];
        src.push('#version 300 es');
        src.push("// Points batching occlusion 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;");

        this._addMatricesUniformBlockLines(src);

        src.push("uniform float pointSize;");
        if (pointsMaterial.perspectivePoints) {
            src.push("uniform float nearPlaneHeight;");
        }

        if (scene.logarithmicDepthBufferEnabled) {
            src.push("uniform float logDepthBufFC;");
            src.push("out float vFragDepth;");
        }
        if (clipping) {
            src.push("out vec4 vWorldPosition;");
            src.push("out float vFlags;");
        }
        src.push("void main(void) {");

        // colorFlag = NOT_RENDERED | COLOR_OPAQUE | COLOR_TRANSPARENT
        // renderPass = COLOR_OPAQUE
        // Only opaque objects can be occluders

        src.push(`int colorFlag = int(flags) & 0xF;`);
        src.push(`if (colorFlag != 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("vec4 clipPos = projMatrix * viewPosition;");
        if (scene.logarithmicDepthBufferEnabled) {
            src.push("vFragDepth = 1.0 + clipPos.w;");
        }
        src.push("  gl_Position = clipPos;");
        if (pointsMaterial.perspectivePoints) {
            src.push("gl_PointSize = (nearPlaneHeight * pointSize) / clipPos.w;");
            src.push("gl_PointSize = max(gl_PointSize, " + Math.floor(pointsMaterial.minPerspectivePointSize) + ".0);");
            src.push("gl_PointSize = min(gl_PointSize, " + Math.floor(pointsMaterial.maxPerspectivePointSize) + ".0);");
        } else {
            src.push("gl_PointSize = pointSize;");
        }
        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("// Points batching occlusion 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("uniform float logDepthBufFC;");
            src.push("in float vFragDepth;");
        }
        if (clipping) {
            src.push("in vec4 vWorldPosition;");
            src.push("in float vFlags;");
            for (let 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("out vec4 outColor;");
        src.push("void main(void) {");
        if (scene.pointsMaterial.roundPoints) {
            src.push("  vec2 cxy = 2.0 * gl_PointCoord - 1.0;");
            src.push("  float r = dot(cxy, cxy);");
            src.push("  if (r > 1.0) {");
            src.push("       discard;");
            src.push("  }");
        }
        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 = log2( vFragDepth ) * logDepthBufFC * 0.5;");
        }
        src.push("   outColor = vec4(0.0, 0.0, 1.0, 1.0); "); // Occluders are blue
        src.push("}");
        return src;
    }
}

export {VBOBatchingPointsOcclusionRenderer};