example1_2fb.cpp

#define LGFX_USE_V1
#include <LovyanGFX.hpp>

#include "esp_gcs_display_parallel16_9488.h"

// =====================================================
// Globals
// =====================================================
LGFX_Parallel_9488 lcd;

const int COLOR_DEPTH = 8;
const int FRAMEBUFFER_COUNT = 2;
LGFX_Sprite fb[FRAMEBUFFER_COUNT] = { LGFX_Sprite(&lcd), LGFX_Sprite(&lcd) };

volatile int draw_index = 0;

float fps = 0.0f;
uint32_t frame_counter = 0;
uint32_t last_fps_update = 0;

const int SCREEN_W = lcd.width();
const int SCREEN_H = lcd.height();
const int CENTER_X = SCREEN_W / 2;
const int CENTER_Y = SCREEN_H / 2;


// =====================================================
// Setup
// =====================================================
void setup() {
    pinMode(LCD_CS, OUTPUT);
    pinMode(LCD_BLK, OUTPUT);
    digitalWrite(LCD_CS, LOW);
    digitalWrite(LCD_BLK, HIGH);
    
    lcd.init();
    lcd.initDMA();
    lcd.setRotation(1);
    lcd.fillScreen(TFT_BLACK);
    lcd.drawCenterString("Initializing...", SCREEN_W / 2, SCREEN_H / 2, 2);    

    // Try 4-bit first, then 8-bit if you need more colors
    for (int i = 0; i < FRAMEBUFFER_COUNT; i++) {
        fb[i].setPsram(false);
        fb[i].setColorDepth(COLOR_DEPTH);
        
        if (!fb[i].createSprite(SCREEN_W, SCREEN_H)) {
            log_i("Failed to allocate fb[%d]", i);
            lcd.drawCenterString("Framebuffer allocation failed!", SCREEN_W / 2, SCREEN_H / 2, 2);
            while (true) delay(1000);
        }
        
        // // Simple 4-bit palette
        // fb[i].setPaletteColor(0, TFT_BLACK);
        // fb[i].setPaletteColor(1, TFT_WHITE);
        // fb[i].setPaletteColor(2, TFT_BLUE);
        // fb[i].setPaletteColor(3, TFT_YELLOW);
        // for (int c = 4; c < 16; c++) {
        //     fb[i].setPaletteColor(c, TFT_BLACK);
        // }
        
        fb[i].fillScreen(TFT_BLACK);
    }

    lcd.startWrite();
    last_fps_update = millis();
    
    log_i("Free after alloc: %d", ESP.getFreePsram());
}


// =====================================================
// Loop - Simple and Fast
// =====================================================
void loop() {
    // Wait for previous DMA to finish
    while (lcd.dmaBusy()) { }

    LGFX_Sprite* fb_current = &fb[draw_index];

    // Calculate position
    static float angle = 0.0f;
    int x = CENTER_X + (int)(sin(angle) * 100);
    int y = CENTER_Y + (int)(cos(angle) * 100);
    angle += 0.05f;

    // Draw - fillScreen is actually fastest for full updates
    fb_current->fillScreen(TFT_BLACK);  // 0 = BLACK
    fb_current->fillCircle(x, y, 40, TFT_BLUE);  // 2 = BLUE
    
    fb_current->setTextSize(1);
    fb_current->setTextColor(TFT_YELLOW, TFT_TRANSPARENT);  // WHITE on BLACK
    fb_current->drawString("Double Buffer (4-bit)", 50, 10);
    
    fb_current->setTextSize(2);
    char buf[32];
    snprintf(buf, sizeof(buf), "FPS: %.1f", fps);
    fb_current->setTextColor(TFT_RED, TFT_TRANSPARENT);  // YELLOW on BLACK
    fb_current->drawString(buf, 10, SCREEN_H - 30);

    // Push via DMA
    lcd.pushImageDMA(
        0, 0, SCREEN_W, SCREEN_H,
        fb_current->getBuffer(),
        fb_current->getColorDepth(),
        fb_current->getPalette()
    );

    // Swap buffers
    draw_index = 1 - draw_index;

    // FPS tracking
    frame_counter++;
    uint32_t now = millis();
    if (now - last_fps_update >= 1000) {
        fps = (frame_counter * 1000.0f) / (now - last_fps_update);
        frame_counter = 0;
        last_fps_update = now;        
    }
}