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fix(ili9341): handle MADCTL so landscape (setRotation 1/3) renders 

The ILI9341 emulator hardcoded SCREEN_W=240 SCREEN_H=320 and silently
ignored every command except CASET/PASET/RAMWR/SWRESET. The block
comment even bragged about it ("All others are silently accepted —
init sequences, DISPON, MADCTL…").

That's fine for portrait sketches, but every landscape demo —
including the new Pico Doom raycaster — calls tft.setRotation(1) or
setRotation(3). Adafruit_ILI9341 translates those into MADCTL 0x36
with the MV (row/column exchange) bit set, then issues CASET windows
with X∈[0..319] and PASET windows with Y∈[0..239]. The emulator's
bounds check `curX > colEnd` would let curX reach 319, but the
buffer write `id.data[(curY*240 + curX)*4]` would land in a slot
that belongs to a different row — and worse, the SCREEN_W=240
ceiling silently truncated everything past column 239. Net result:
black screen for any rotated sketch.

Fix: parse MADCTL (0x36) and treat CASET/PASET as LOGICAL coordinates.
At pixel-write time, remap (curX, curY) → physical (px, py) using the
MV/MX/MY bits, then write into the still-physical 240×320 imageData.
SWRESET resets MADCTL back to portrait defaults (matches the
datasheet's reset semantics).

  MADCTL bit  Mask    Meaning
  D7 MY       0x80    row mirror
  D6 MX       0x40    column mirror
  D5 MV       0x20    swap X/Y (landscape)

Verified by rebuilding (vite OSS+pro). The fix is data-flow only —
no API change, no new dependency. Pico Doom should now actually
render its title screen + raycast frames in /examples on the
raspberry-pi-pico board.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
This commit is contained in:
David Montero Crespo 2026-05-14 23:19:03 -03:00
parent 9ace6b7476
commit 6edc715e8d
1 changed files with 57 additions and 5 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

62
frontend/src/simulation/parts/ComplexParts.ts
View File

@ -787,8 +787,17 @@ PartSimulationRegistry.register('lcd2002', createLcdSimulation(20, 2));
* - 0x2A CASET – set column address window
* - 0x2B PASET – set page (row) address window
* - 0x2C RAMWR – stream RGB-565 pixel data
* - 0x36 MADCTL – memory access control (rotation MV / MX / MY bits)
* - 0x01 SWRESET – clear display
* - All others are silently accepted (init sequences, DISPON, MADCTL…)
* - All others are silently accepted (DISPON, COLMOD, …)
*
* Coordinates in CASET/PASET are LOGICAL — driver libraries (Adafruit_
* ILI9341 etc.) call `setRotation(1|3)` which emits MADCTL with MV set
* and then writes CASET in 0..319 / PASET in 0..239. The emulator keeps
* the underlying canvas at the panel's native 240×320 and remaps each
* pixel through MV/MX/MY at write time. Without this, every landscape
* sketch (rotation 1 or 3) used to render to nothing because the X
* bound check filtered out anything past column 239.
*
* DC/RS pin: LOW = command byte, HIGH = data bytes.
*/
@ -865,6 +874,14 @@ const ili9341Simulation = {
let pixelHiByte = 0;
let pixelByteCount = 0;
// ── MADCTL state ──────────────────────────────────────────────────
// ILI9341 0x36 command bits we care about (datasheet §8.2.29). Set
// by setRotation() in every Adafruit-style driver; default is
// rotation 0 = all bits clear (portrait, no swap, no mirror).
let madMV = false; // row/column exchange — landscape orientation
let madMX = false; // column address mirror
let madMY = false; // row address mirror
// ── DC pin tracking ───────────────────────────────────────────────
let dcState = false; // LOW = command, HIGH = data
const pinDC = getArduinoPinHelper('D/C');
@ -880,8 +897,32 @@ const ili9341Simulation = {
}
// ── Pixel writer ──────────────────────────────────────────────────
// curX / curY / col* / row* are LOGICAL coordinates — the values the
// driver thinks it's writing to. In rotation 0 logical = physical.
// In rotation 1/3 (MV set) the driver iterates X in 0..319 and Y in
// 0..239; we swap them at the last possible moment before touching
// the imageData buffer (which is always physically 240 wide × 320 tall).
const writePixel = (hi: number, lo: number) => {
if (curX > colEnd || curY > rowEnd || curY >= SCREEN_H || curX >= SCREEN_W) return;
if (curX > colEnd || curY > rowEnd) return;
// Map logical → physical via MADCTL.
let physX = curX;
let physY = curY;
if (madMV) {
physX = curY;
physY = curX;
}
if (madMX) physX = (SCREEN_W - 1) - physX;
if (madMY) physY = (SCREEN_H - 1) - physY;
if (physX < 0 || physX >= SCREEN_W || physY < 0 || physY >= SCREEN_H) {
curX++;
if (curX > colEnd) {
curX = colStart;
curY++;
}
return;
}
const id = getOrCreateImageData();
const color = (hi << 8) | lo;
@ -889,7 +930,7 @@ const ili9341Simulation = {
const g = ((color >> 5) & 0x3f) * 4;
const b = (color & 0x1f) * 8;
const idx = (curY * SCREEN_W + curX) * 4;
const idx = (physY * SCREEN_W + physX) * 4;
id.data[idx] = r;
id.data[idx + 1] = g;
id.data[idx + 2] = b;
@ -911,13 +952,16 @@ const ili9341Simulation = {
pixelByteCount = 0;
if (cmd === 0x01) {
// SWRESET – clear framebuffer
// SWRESET – clear framebuffer + reset MADCTL to defaults
colStart = 0;
colEnd = SCREEN_W - 1;
rowStart = 0;
rowEnd = SCREEN_H - 1;
curX = 0;
curY = 0;
madMV = false;
madMX = false;
madMY = false;
imageData = null;
if (ctx) ctx.clearRect(0, 0, SCREEN_W, SCREEN_H);
}
@ -953,7 +997,15 @@ const ili9341Simulation = {
curY = rowStart;
}
break;
// All other commands (DISPON, MADCTL, COLMOD…) just buffer data
case 0x36: // MADCTL – memory access control (rotation / mirror)
if (dataBytes.length === 1) {
const m = dataBytes[0];
madMY = (m & 0x80) !== 0;
madMX = (m & 0x40) !== 0;
madMV = (m & 0x20) !== 0;
}
break;
// All other commands (DISPON, COLMOD…) just buffer data
}
};