Overview

ESP Emote GFX is a lightweight graphics framework for ESP-IDF that provides a simple yet powerful API for rendering graphics on embedded displays. It is designed with memory efficiency and performance in mind, making it ideal for resource-constrained embedded systems.

Architecture

The framework is built around a core object system where all graphical elements (images, labels, animations, QR codes) are treated as objects. These objects share common properties like position, size, visibility, and alignment.

Core Components

Core System

The core system (gfx_core) manages:

Graphics context initialization and deinitialization
Buffer management (internal or external)
Rendering pipeline
Thread safety with mutex locking
Screen refresh and invalidation

Object System

The object system (gfx_obj) provides:

Base object structure for all graphical elements
Position and size management
Alignment system (similar to LVGL)
Visibility control
Object lifecycle management

Timer System

The timer system (gfx_timer) provides:

High-resolution timers for animations
Callback-based timer events
Repeat count and period control
System tick management

Widgets

Memory Management

The framework supports two buffer management modes:

Internal Buffers

The framework automatically allocates and manages frame buffers internally. This is the simplest mode but requires sufficient heap memory.

External Buffers

You can provide your own buffers, allowing you to:

Use memory-mapped regions
Control buffer placement (SRAM, SPIRAM, etc.)
Optimize for specific memory constraints

Thread Safety

All widget operations should be performed within a graphics lock to ensure thread safety:

gfx_emote_lock(handle);
// Perform operations
gfx_obj_set_pos(obj, x, y);
gfx_label_set_text(label, "New text");
gfx_emote_unlock(handle);

Dependencies

ESP-IDF 5.0 or higher
FreeType (for TTF/OTF font support)
ESP New JPEG (for JPEG decoding)

License

This project is licensed under the Apache License 2.0.