From 9ab310d2a34992c7c7b71a80f1facdccea987d07 Mon Sep 17 00:00:00 2001
From: Stewart Allen <sa@grid.space>
Date: Mon, 26 Jul 2021 17:08:52 -0400
Subject: [PATCH] add rgb bands for thumb/preview as placeholder

---
 src/add/class.js        |  5 +++++
 src/mode/sla/export.js  | 22 +++++++++++++++++++++-
 src/mode/sla/x_cxdlp.js | 31 +++++++++++++++++++++++++++----
 3 files changed, 53 insertions(+), 5 deletions(-)

diff --git a/src/add/class.js b/src/add/class.js
index f9f099fe..260800be 100644
--- a/src/add/class.js
+++ b/src/add/class.js
@@ -31,6 +31,11 @@ self.ArrayWriter = class ArrayWriter {
         this.array[this.pos++] = v & 0xff;
     }
 
+    writeBytes(bytes) {
+        this.array.appendAll(bytes);
+        this.pos += bytes.length;
+    }
+
     toBuffer() {
         return new Uint8ClampedArray(this.array).buffer;
     }
diff --git a/src/mode/sla/export.js b/src/mode/sla/export.js
index e95f3d79..c7454d14 100644
--- a/src/mode/sla/export.js
+++ b/src/mode/sla/export.js
@@ -107,12 +107,32 @@
             }
 
             // generate thumb, preview1, preview2
+            let thumb = [];
+            for (let x=0; x<116; x++) {
+                for (let y=0; y<116; y++) {
+                    let val = 1 << Math.floor(x / 7.25);
+                    thumb.push((val >> 8) & 0xff);
+                    thumb.push(val & 0xff);
+                }
+            }
+            let preview1 = [];
+            for (let x=0; x<290; x++) {
+                for (let y=0; y<290; y++) {
+                    let val = 1 << Math.floor(x / 18.125);
+                    preview1.push((val >> 8) & 0xff);
+                    preview1.push(val & 0xff);
+                }
+            }
+            let preview2 = preview1;
 
             let file = CXDLP.export({
                 settings,
                 width,
                 height,
-                slices
+                slices,
+                thumb,
+                preview1,
+                preview2
             });
             ondone({
                 width: width,
diff --git a/src/mode/sla/x_cxdlp.js b/src/mode/sla/x_cxdlp.js
index fcf542f1..5d116b3c 100644
--- a/src/mode/sla/x_cxdlp.js
+++ b/src/mode/sla/x_cxdlp.js
@@ -174,6 +174,29 @@
                 }
             }
 
+            output.write_bytes = function(array, len) {
+                if (!array) {
+                    output.skip(len);
+                } else if (array.byteLength) {
+                    if (len !== array.byteLength) {
+                        throw `invalid array length: ${array.byteLength} != ${len}`;
+                    }
+                    // ArrayBuffer
+                    let read = new DataReader(array);
+                    for (let i=0; i<array.byteLength; i++) {
+                        output.writeU8(read.readU8());
+                    }
+                } else if (array.length) {
+                    if (len !== array.length) {
+                        throw `invalid array length: ${array.length} != ${len}`;
+                    }
+                    // standard array
+                    output.writeBytes(array);
+                } else {
+                    throw "invalid byte array";
+                }
+            };
+
             let layers = this.layers;
             this.layer_count = layers.length;
             output.write_string(this.magic1);
@@ -184,11 +207,11 @@
             output.writeU16(this.res_y);
             output.writeU32(this.height);
             output.skip(60);
-            output.skip(26912); // thumb
+            output.write_bytes(this.thumb, 26912); // thumb
             output.writeU16(data_term);
-            output.skip(168200); // preview1
+            output.write_bytes(this.preview1, 168200); // preview1
             output.writeU16(data_term);
-            output.skip(168200); // preview1
+            output.write_bytes(this.preview2, 168200); // preview1
             output.writeU16(data_term);
             output.write_string(this.dim_x, true);
             output.write_string(this.dim_y, true);
@@ -274,7 +297,7 @@
         cxdlp.layer = process.slaSlice.toFixed(5);
         cxdlp.thumb = thumb;
         cxdlp.preview1 = preview1;
-        cxdlp.preview1 = preview2;
+        cxdlp.preview2 = preview2;
         cxdlp.light_on = process.slaLayerOn;
         cxdlp.light_off = process.slaLayerOff;
         // cxdlp.light_pwm = 255;