From 72ee2e7bc0623490d70d521063e348197f643c6a Mon Sep 17 00:00:00 2001
From: Lucas Scharenbroich <lscharen@prowestgis.com>
Date: Thu, 5 Aug 2021 21:19:02 -0500
Subject: [PATCH] First version of Tiled Map import tool

---
 package.json        |  3 +-
 tools/tiled2iigs.js | 91 +++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 93 insertions(+), 1 deletion(-)
 create mode 100644 tools/tiled2iigs.js

diff --git a/package.json b/package.json
index 9ff996d..68b3085 100644
--- a/package.json
+++ b/package.json
@@ -20,7 +20,8 @@
     "build:assets-plant": "node ./tools/png2iigs.js ./assets/plant.png ./emu/bg1a.bin --start-index 6 && node ./tools/pngtoiigs.js ./assets/woz-shifted.png ./emu/bg1b.bin --start-index 6 && node ./tools/pngtoiigs.js ./assets/donut-plains-1-6-color.png ./emu/fg1.bin",
     "build:assets-woz": "node ./tools/png2iigs.js ./assets/woz.png ./emu/bg1a.bin --start-index 6 && node ./tools/pngtoiigs.js ./assets/woz-shifted.png ./emu/bg1b.bin --start-index 6 && node ./tools/pngtoiigs.js ./assets/donut-plains-1-6-color.png ./emu/fg1.bin",
     "build:assets-woz-fatbits": "node ./tools/png2iigs.js ./assets/woz-pixelated.png ./emu/bg1a.bin --start-index 6 && node ./tools/pngtoiigs.js ./assets/woz-shifted.png ./emu/bg1b.bin --start-index 6 && node ./tools/pngtoiigs.js ./assets/donut-plains-1-6-color.png ./emu/fg1.bin",
-    "build:assets-color-cycle": "node ./tools/png2iigs.js ./assets/rotopattern.png ./emu/bg1a.bin --start-index 6 && node ./tools/pngtoiigs.js ./assets/woz-shifted.png ./emu/bg1b.bin --start-index 6 && node ./tools/pngtoiigs.js ./assets/donut-plains-1-6-color.png ./emu/fg1.bin"
+    "build:assets-color-cycle": "node ./tools/png2iigs.js ./assets/rotopattern.png ./emu/bg1a.bin --start-index 6 && node ./tools/pngtoiigs.js ./assets/woz-shifted.png ./emu/bg1b.bin --start-index 6 && node ./tools/pngtoiigs.js ./assets/donut-plains-1-6-color.png ./emu/fg1.bin",
+    "build:map": "node ./tools/tiled2iigs.js ./assets/tiled/world_1-1.json > ./src/Level.s"
   },
   "repository": {
     "type": "git",
diff --git a/tools/tiled2iigs.js b/tools/tiled2iigs.js
new file mode 100644
index 0000000..7556ffa
--- /dev/null
+++ b/tools/tiled2iigs.js
@@ -0,0 +1,91 @@
+/**
+ * Read an exported Tiled project in JSON format and produce Merlin32 output files with
+ * GTE-compatible setup code wrapped around it.
+ */
+ const fs = require('fs').promises;
+ const process = require('process');
+ const { Buffer } = require('buffer');
+ 
+ main(process.argv.slice(2)).then(
+    () => process.exit(0), 
+    (e) => {
+        console.error(e);
+        process.exit(1);
+    }
+);
+
+function emitHeader() {
+    console.log('; Tiled Map Export');
+    console.log(';');
+    console.log('; This is a generated file. Do not modify.');
+}
+
+async function main(argv) {
+    // Read in the JSON data
+    const doc = JSON.parse(await fs.readFile(argv[0]));
+
+    // Make sure it's a map format we can handle
+    if (doc.infinite) {
+        throw new Error('Cannot import infinite maps.');
+    }
+
+    // Require 8x8 tiles
+    if (doc.tileheight !== 8 || doc.tilewidth !== 8) {
+        throw new Error('Only 8x8 tiles are supported');
+    }
+
+    // The total map size must be less than 32768 tiles because we limit the map to one data bank
+    // and the tiles are stored in GTE as 16-bit values.
+    if (doc.height * doc.width >= 32768) {
+        throw new Error('The tile map must have less than 32,768 tiles');
+    }
+
+    // Look at the tile layers.  We support a maximum of two tile layers.
+    const tileLayers = doc.layers.filter(l => l.type === 'tilelayer');
+    if (tileLayers.length === 0) {
+        throw new Error('There must be at least one tile layer defined for the map');
+    }
+
+    if (tileLayers.length > 2) {
+        throw new Error('The map cannot have more than two tile layers');
+    }
+
+    // Sort the tile layers by ID.  The lower ID is considered to be the "front" layer
+    tileLayers.sort((first, second) => first.id <= second.id);
+
+    // Ok, looks good.  Write out the source code
+    emitHeader();
+    emitBG0Layer(tileLayers[0]);
+    if (tileLayers.length > 1) {
+        emigBG1Layer(tileLayers[1]);
+    }
+}
+
+function emitBG0Layer(layer) {
+    const label = layer.name.split(' ').join('_');
+    const initCode = `
+BG0SetUp
+        lda #${layer.width}
+        sta TileMapWidth
+        lda #${layer.height}
+        sta TileMapHeight
+        lda #${label}
+        sta TileMapPtr
+        lda #^${label}
+        sta TileMapPtr+2
+        rts
+    `;
+    console.log(initCode);
+    console.log(`${label}`);
+
+    // Print out the data in groups of N
+    const N = 16;
+    const chunks = [];
+    const tileIDs = layer.data;
+    for (let i = 0; i < tileIDs.length; i += N) {
+        chunks.push(tileIDs.slice(i, i + N))
+    }
+    for (const chunk of chunks) {
+        console.log('        dw ' + chunk.join(','));
+    }
+}
\ No newline at end of file