src/viewer/scene/model/vbo/instancing/triangles/renderers/TrianglesShadowRenderer.js

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

/**
 * Renders InstancingLayer fragment depths to a shadow map.
 *
 * @private
 */
export class TrianglesShadowRenderer extends TrianglesInstancingRenderer {

    _buildVertexShader() {
        const scene = this._scene;
        const sectionPlanesState = scene._sectionPlanesState;
        const clipping = sectionPlanesState.getNumAllocatedSectionPlanes() > 0;
        const src = [];
        src.push("#version 300 es");
        src.push("// Instancing geometry shadow drawing vertex shader");
        src.push("in vec3 position;");
        if (scene.entityOffsetsEnabled) {
            src.push("in vec3 offset;");
        }
        src.push("in vec4 color;");
        src.push("in float flags;");
        src.push("in vec4 modelMatrixCol0;");
        src.push("in vec4 modelMatrixCol1;");
        src.push("in vec4 modelMatrixCol2;");
        src.push("uniform mat4 shadowViewMatrix;");
        src.push("uniform mat4 shadowProjMatrix;");

        this._addMatricesUniformBlockLines(src);

        if (clipping) {
            src.push("out vec4 vWorldPosition;");
            src.push("out float vFlags;");
        }
        src.push("void main(void) {");
        src.push(`int colorFlag = int(flags) & 0xF;`);
        src.push("bool visible = (colorFlag > 0);");
        src.push("bool transparent  = ((float(color.a) / 255.0) < 1.0);");
        src.push(`if (!visible || transparent) {`);
        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 = 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  = shadowViewMatrix * worldPosition; ");

        if (clipping) {
            src.push("vWorldPosition = worldPosition;");
            src.push("vFlags = flags;");
        }
        src.push("  gl_Position = shadowProjMatrix * viewPosition;");
        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("// Instancing geometry depth drawing 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, len = sectionPlanesState.getNumAllocatedSectionPlanes(); i < len; 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("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, len = sectionPlanesState.getNumAllocatedSectionPlanes(); i < len; 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(packNormalToRGB(vViewNormal), 1.0); ");
        src.push("}");
        return src;
    }
}