const express = require("express");
const path = require("path");
const { port, width, height } = require("./config.json");
const app = express();
const indexResponse = `
draw
send a get request to /set/[x]/[y]/[r]/[g]/[b] to change the image
`;
let image = Buffer.alloc(14 + 12 + width * height * 3);
app.get("/image", (req, res) => {
res.writeHead(200, { "Content-Type": "image/bmp", "Content-Length": image.length });
res.end(image);
});
app.get("/", (req, res) => {
res.send(indexResponse);
});
app.get("/set/:x/:y/:r/:g/:b", (req, res) => {
let { x, y, r, g, b } = req.params;
[ x, y, r, g, b ] = [ +x, +y, +r, +g, +b ];
if (x >= width || y >= height) {
res.status(400).send({ success: 0, error: "coordinates outside of bounds" });
} else if (r >= 256 || g >= 256 || b >= 256) {
res.status(400).send({ success: 0, error: "check your colour values....." });
} else {
const pos = (x + (height - y - 1) * width) * 3 + 26;
image[pos + 0] = r;
image[pos + 1] = g;
image[pos + 2] = b;
res.status(200).send({ success: 1 });
}
});
app.listen(port, () => {
// manually writing the header :michael:
const length = image.length;
image.set([
0x42, 0x4D,
(length >> 0) & 0xFF, (length >> 8) & 0xFF, (length >> 16) & 0xFF, (length >> 24) & 0xFF,
0x00, 0x00,
0x00, 0x00,
0x1A, 0x00, 0x00, 0x00,
0x0C, 0x00, 0x00, 0x00,
(width >> 0) & 0xFF, (width >> 8) & 0xFF,
(height >> 0) & 0xFF, (height >> 8) & 0xFF,
0x01, 0x00,
0x18, 0x00
], 0);
console.log(`deatj at http://0.0.0.0:${port}/`);
});