From 9d9045b4d3e5f21ca5b8f83020f4ef5469c57b97 Mon Sep 17 00:00:00 2001
From: blobt <klm777x7@gmai.com>
Date: Wed, 5 May 2021 10:29:11 +0800
Subject: [PATCH] =?UTF-8?q?=E5=AE=8C=E6=88=90primitives?=
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---
 src/render/core/Primitives.ts | 39 +++++++++++++++++++++++++++++++++++
 1 file changed, 39 insertions(+)

diff --git a/src/render/core/Primitives.ts b/src/render/core/Primitives.ts
index deb58d9c..67c5ba2a 100755
--- a/src/render/core/Primitives.ts
+++ b/src/render/core/Primitives.ts
@@ -223,4 +223,43 @@ export class Cube {
         ret.indices.push(2, 6, 4, 2, 4, 0); // 下面
         return ret;
     }
+}
+
+export class GridPlane {
+    /**
+     * @var
+     */
+    public sx: number;
+    public sy: number;
+    public nx: number;
+    public ny: number;
+
+    public constructor(sx: number = 10, sy: number = 10, nx: number = 10, ny: number = 10) {
+        this.sx = sx;
+        this.sy = sy;
+        this.nx = nx;
+        this.ny = ny;
+    }
+
+    public makeGeometryData(): GeometryData {
+        let ret: GeometryData = new GeometryData();
+        for (let iy: number = 0; iy <= this.ny; iy++) {
+            for (let ix: number = 0; ix <= this.nx; ix++) {
+                let u: number = ix / this.nx;
+                let v: number = iy / this.ny;
+                let x: number = -this.sx / 2 + u * this.sx; // starts on the left
+                let y: number = this.sy / 2 - v * this.sy; // starts at the top
+                ret.positions.push(new vec3([x, y, 0]));
+                ret.uvs.push(new vec2([u, 1.0 - v]));
+                ret.normals.push(new vec3([0, 0, 1]));
+                if (iy < this.ny && ix < this.nx) {
+                    {
+                        ret.indices.push(iy * (this.nx + 1) + ix, (iy + 1) * (this.nx + 1) + ix + 1, iy * (this.nx + 1) + ix + 1);
+                        ret.indices.push((iy + 1) * (this.nx + 1) + ix + 1, iy * (this.nx + 1) + ix, (iy + 1) * (this.nx + 1) + ix);
+                    }
+                }
+            }
+        }
+        return ret;
+    }
 }
\ No newline at end of file