From 7acfb643177aaf6c03fcf178e053d98c78984683 Mon Sep 17 00:00:00 2001
From: Miloslav Ciz <drummyfish@disroot.org>
Date: Tue, 17 Jun 2025 02:31:32 +0200
Subject: [PATCH] Add ESPboy frontend

---
 frontend_espboy/frontend_espboy.ino | 139 ++++++++++++++++++++++++++++
 game.h                              |   3 -
 renderer.h                          |   7 ++
 3 files changed, 146 insertions(+), 3 deletions(-)
 create mode 100644 frontend_espboy/frontend_espboy.ino

diff --git a/frontend_espboy/frontend_espboy.ino b/frontend_espboy/frontend_espboy.ino
new file mode 100644
index 0000000..07d5377
--- /dev/null
+++ b/frontend_espboy/frontend_espboy.ino
@@ -0,0 +1,139 @@
+/**
+  @file frontend_espboy.ino
+
+  Experimental Licar frontend for ESPboy, unstable and unplayable, but able to
+  load a few of the smallest maps and allow driving a bit.
+*/
+
+#include <Arduino.h>
+#include <Adafruit_MCP23017.h>
+#include <Adafruit_MCP4725.h>
+#include <TFT_eSPI.h>
+
+#define MCP23017address 0
+#define MCP4725address  0x60
+
+Adafruit_MCP23017 mcp;
+Adafruit_MCP4725 dac;
+TFT_eSPI tft;
+
+#define LCR_SETTING_RESOLUTION_X 64
+#define LCR_SETTING_RESOLUTION_Y 64
+#define LCR_SETTING_MUSIC 0
+#define LCR_SETTING_GHOST_MAX_SAMPLES 0
+#define LCR_SETTING_332_COLOR 1
+#define LCR_LOADING_COMMAND wdt_reset();
+#define S3L_SORT 0
+#define LCR_SETTING_MAP_MAX_BLOCKS 512
+#define LCR_SETTING_MAX_MAP_VERTICES 500
+#define LCR_SETTING_MAX_MAP_TRIANGLES 600
+#define LCR_SETTING_REPLAY_MAX_SIZE 0
+#define LCR_SETTING_CAR_SHADOW 0
+#define LCR_SETTING_PARTICLES 0
+#define LCR_SETTING_LOG_LEVEL 0
+#define LCR_SETTING_LOD_DISTANCE 100
+#define LCR_SETTING_CAR_ANIMATION_SUBDIVIDE 0
+
+#define LCR_SETTING_FPS 25
+
+#define LCR_SETTING_POTATO_GRAPHICS 1
+
+#define LCR_SETTING_ENABLE_DATA_FILE 0
+#define LCR_SETTING_ONLY_SMALL_MAPS 1
+
+#include "game.h"
+
+uint8_t gamescreen[LCR_SETTING_RESOLUTION_X * LCR_SETTING_RESOLUTION_Y];
+uint8_t keys;
+
+void LCR_drawPixel(unsigned long index, uint16_t color)
+{
+  gamescreen[index] = color & 0xff;
+}
+
+void LCR_sleep(uint16_t timeMs)
+{
+}
+
+uint8_t LCR_keyPressed(uint8_t key)
+{
+  switch (key)
+  {
+    case LCR_KEY_UP:    return keys & 0x02; break;
+    case LCR_KEY_DOWN:  return keys & 0x04; break;
+    case LCR_KEY_RIGHT: return keys & 0x08; break;
+    case LCR_KEY_LEFT:  return keys & 0x01; break;
+    case LCR_KEY_A:     return keys & 0x10; break;
+    case LCR_KEY_B:     return keys & 0x20; break;
+    default: return 0; break;
+  }
+}
+
+char LCR_getNextDataFileChar(void)
+{
+  return 0;
+}
+
+void LCR_appendDataStr(const char *str)
+{
+  return;
+}
+
+void setup()
+{
+  *((volatile uint32_t *) 0x60000900) &= ~(1); // disable watchdog
+
+  dac.begin(MCP4725address);
+  delay (100);
+  dac.setVoltage(0,false);
+  mcp.begin(MCP23017address);
+  delay(100);
+
+  // buttons
+  for (uint8_t i = 0; i < 8; i++)
+  {
+    mcp.pinMode(i,INPUT);
+    mcp.pullUp(i,HIGH);
+  }
+
+  mcp.pinMode(8,OUTPUT);
+  mcp.digitalWrite(8,LOW);
+  
+  tft.begin();
+  delay(100);
+  tft.setRotation(0);
+
+  tft.setAddrWindow(0,128,0,128);
+  tft.fillScreen(TFT_BLACK);
+
+  dac.setVoltage(4095,true); // backlight
+
+  LCR_gameInit(0,0);
+}
+
+void loop()
+{
+  keys = ~mcp.readGPIOAB() & 255;
+  wdt_reset();
+  LCR_gameStep(millis());  
+
+  for (int y = 0; y < LCR_SETTING_RESOLUTION_Y; ++y)
+  {
+    for (int i = 0; i < 2; ++i)
+    {
+      uint8_t *pixel = gamescreen + y * LCR_SETTING_RESOLUTION_X;
+
+      for (int x = 0; x < LCR_SETTING_RESOLUTION_X; ++x)
+      {
+        uint16_t color = *pixel;
+        color =
+          ((color & 0xe0) << 8) | ((color & 0x1c) << 6) | ((color & 0x03) << 3);
+
+        tft.pushColor(color);
+        tft.pushColor(color);
+
+        pixel++;
+      }
+    }
+  }
+}
diff --git a/game.h b/game.h
index 79ec27f..d096877 100644
--- a/game.h
+++ b/game.h
@@ -366,8 +366,6 @@ struct
   } dataFile;
 
 #define LCR_GHOST_SAMPLE_SIZE 5
-
-#if LCR_SETTING_GHOST_MAX_SAMPLES != 0
   struct
   {
     uint8_t active;
@@ -379,7 +377,6 @@ struct
                            allow ghosts for even long replays. */
     int16_t offset[3];     ///< Small correcting position offset.
   } ghost;
-#endif
 
 #ifdef LCR_FPS_GET_MS
   uint16_t renderFrameMS;
diff --git a/renderer.h b/renderer.h
index ff3dd5b..02d2153 100644
--- a/renderer.h
+++ b/renderer.h
@@ -41,6 +41,13 @@
   #define S3L_PERSPECTIVE_CORRECTION 0
   #define S3L_NEAR_CROSS_STRATEGY 1
   #define S3L_FLAT 1
+  #define S3L_Z_BUFFER 0
+
+  #ifndef S3L_SORT
+    #define S3L_SORT 1
+  #endif
+
+  #define S3L_MAX_TRIANGES_DRAWN 48
 #endif
  
 #define S3L_NEAR (10 * (S3L_F / 16)) // too low value will cause overflows