From d17677e2ff15ff037740545bc6f3fedc438f204a Mon Sep 17 00:00:00 2001
From: Stewart Allen <stewart.allen@gmail.com>
Date: Mon, 30 Nov 2020 23:01:47 -0500
Subject: [PATCH] add new stack class

---
 src/kiri/stack.js | 218 ++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 218 insertions(+)
 create mode 100644 src/kiri/stack.js

diff --git a/src/kiri/stack.js b/src/kiri/stack.js
new file mode 100644
index 00000000..f1733066
--- /dev/null
+++ b/src/kiri/stack.js
@@ -0,0 +1,218 @@
+/** Copyright Stewart Allen <sa@grid.space> -- All Rights Reserved */
+
+"use strict";
+
+(function() {
+
+    class Stack {
+        constructor(view) {
+            this.view = view.newGroup();
+            this.slices = [];
+            this.freeMem = true;
+        }
+
+        size() {
+            return this.slices.length;
+        }
+
+        setVisible(newMin, newMax) {
+            for (let i=0, s=this.slices, len=s.length; i<len; i++) {
+                s[i].visible = i >= newMin && i <= newMax;
+            }
+        }
+
+        addLayers(layers) {
+            // each slice gets a group so the slice can be toggled efficiently
+            let group = this.view.newGroup();
+            this.slices.push(group);
+            let map = this.renderLayers(layers, group);
+            // by default release memory after layers are rendered
+            if (this.freeMem) {
+                layers.init();
+            }
+            // return map of layers to materials (so they can be toggled on/off)
+            return map;
+        }
+
+        renderLayers(layers, group) {
+            const map = {}
+            for (const [label, layer] of Object.entries(layers.layers)) {
+                map[label] = this.renderLayer(layer, group);
+            }
+            return map;
+        }
+
+        renderLayer(layer, group) {
+            function addPoly(vertices, poly) {
+                const points = poly.points, len = points.length;
+                for (let i=1; i<len; i++) {
+                    const p1 = points[i-1], p2 = points[i];
+                    vertices.push(new THREE.Vector3(p1.x, p1.y, p1.z));
+                    vertices.push(new THREE.Vector3(p2.x, p2.y, p2.z));
+                }
+                if (!poly.open) {
+                    const p1 = points[len - 1], p2 = points[0];
+                    vertices.push(new THREE.Vector3(p1.x, p1.y, p1.z));
+                    vertices.push(new THREE.Vector3(p2.x, p2.y, p2.z));
+                }
+            }
+
+            const { polys, lines, faces, cface, paths, cpath, color, off } = layer;
+            const defstate = !off;
+            const mats = [];
+            mats.state = defstate;
+
+            if (polys.length || lines.length) {
+                const vert = []; // vertexes
+                const mat = []; // materials
+                const grp = []; // material groups
+                const geo = new THREE.BufferGeometry();
+                // map all the poly and line colors for re-use
+                const cmap = {}
+                let cidx = 0;
+                let last = undefined;
+                for (let i=0, il=polys.length; i<il; i++) {
+                    const vl = vert.length;
+                    const poly = polys[i];
+                    addPoly(vert, poly);
+                    const pc = poly.color !== undefined ? { line: poly.color, opacity: color.opacity } : color;
+                    const pk = pc.line;
+                    const cc = cmap[pk] = cmap[pk] || { idx: cidx++, mat: createLineMaterial(pc, mat) };
+                    if (last !== pk) {
+                        if (grp.length) {
+                            // rewrite counts for last group
+                            const prev = grp[grp.length - 1]
+                            prev[1] = vl;
+                        }
+                        grp.push([vl, Infinity, cc.idx]);
+                        last = pk;
+                    }
+                }
+                // for now, line segments inherit the last color
+                for (let i=0, il=lines.length; i<il; i++) {
+                    const p = lines[i];
+                    vert.push(new THREE.Vector3(p.x, p.y, p.z));
+                }
+                // ensure at least one group using the default color settings
+                if (grp.length === 0) {
+                    grp.push([0, Infinity, 0]);
+                    mat.push(createLineMaterial(color));
+                }
+                mat.forEach(m => m.visible = defstate);
+                for (let i=0; i<grp.length; i++) {
+                    const g = grp[i];
+                    geo.addGroup(g[0], g[1], g[2]);
+                }
+                geo.setFromPoints(vert);
+                const segs = new THREE.LineSegments(geo, mat);
+                group.add(segs);
+                mats.appendAll(mat);
+            }
+            if (faces.length) {
+                const mat = [];
+                if (cface) {
+                    cface.forEach(c => { mat.push(newMat(c)) });
+                } else {
+                    mat.push(newMat(color));
+                }
+                mat.forEach(m => m.visible = defstate);
+                const geo = new THREE.BufferGeometry();
+                if (faces.toFloat32) {
+                    geo.setAttribute('position', new THREE.BufferAttribute(faces.toFloat32(), 3));
+                } else {
+                    geo.setAttribute('position', new THREE.BufferAttribute(faces, 3));
+                }
+                geo.computeFaceNormals();
+                geo.computeVertexNormals();
+                if (cface) {
+                    cface.forEach((c, i) => geo.addGroup(c.start, c.count, i));
+                } else {
+                    geo.addGroup(0, Infinity, 0);
+                }
+                const mesh = new THREE.Mesh(geo, mat);
+                mesh.castShadow = true;
+                mesh.receiveShadow = true;
+                group.add(mesh);
+                mats.appendAll(mat);
+            }
+            if (paths.length) {
+                const mat = [];
+                if (cpath) {
+                    cpath.forEach(c => { mat.push(newMat(c)) });
+                } else {
+                    mat.push(newMat(color));
+                }
+                mat.forEach(m => m.visible = defstate);
+                // const mat = newMat(data);
+                paths.forEach((path, i) => {
+                    const { index, faces, z, colors } = path;
+                    const geo = new THREE.BufferGeometry();
+                    geo.setAttribute('position', new THREE.BufferAttribute(faces, 3));
+                    geo.setIndex(index);
+                    geo.computeFaceNormals();
+                    geo.computeVertexNormals();
+                    if (cpath) {
+                        cpath.forEach((c, i) => geo.addGroup(c.start, c.count, i));
+                    } else {
+                        geo.addGroup(0, Infinity, 0);
+                    }
+                    const mesh = new THREE.Mesh(geo, mat);
+                    mesh.position.z = z;
+                    mesh.castShadow = true;
+                    mesh.receiveShadow = true;
+                    group.add(mesh);
+                });
+                mats.appendAll(mat);
+            }
+
+            mats.forEach(mat => mat.visible = defstate);
+            return mats;
+        }
+    }
+
+    self.kiri.Stack = Stack;
+
+    let shininess = 15,
+        specular = 0x444444,
+        emissive = 0x101010,
+        metalness = 0,
+        roughness = 0.3,
+        newMat = createPhongMaterial;
+
+    function createLineMaterial(color, array) {
+        const opacity = color.opacity || 1;
+        const mat = new THREE.LineBasicMaterial({
+            transparent: true,
+            opacity: opacity,
+            color: color.line
+        });
+        if (array) {
+            array.push(mat);
+        }
+        return mat;
+    }
+
+    function createStandardMaterial(color) {
+        return new THREE.MeshStandardMaterial({
+            emissive,
+            roughness,
+            metalness,
+            transparent: color.opacity != 1,
+            opacity: color.opacity || 1,
+            color: color.face,
+            side: THREE.DoubleSide
+        });
+    }
+
+    function createPhongMaterial(color) {
+        return new THREE.MeshPhongMaterial({
+            shininess,
+            specular,
+            transparent: color.opacity != 1,
+            opacity: color.opacity || 1,
+            color: color.face,
+            side: THREE.DoubleSide
+        });
+    }
+
+})();