HAL EPIC Example

EPIC (ePicasso) is our self-developed graphics engine, a hardware acceleration module specifically designed for 2D/2.5D image processing, mainly used to offload CPU load in image operations and improve image processing efficiency.

Overview

This program is a graphics blending example based on HAL (Hardware Abstraction Layer) interface and EPIC. It demonstrates how to use the HAL interface to control the EPIC hardware module for layer blending (Alpha Blending), superimposing two rectangular layers with transparency, and finally displaying them on the LCD screen.

Supported Development Boards

  • sf32lb52-lchspi-ulp

  • sf32lb52-nano_52j

  • sf32lb52-lcd_n16r8

Example Function Introduction

Main process as follows:

  1. Initialize EPIC and its underlying EZIP module.

  2. Use HAL_EPIC_FillStart() to draw blue and red rectangles in two display memory buffers respectively.

  3. Set layer parameters and call HAL_EPIC_BlendStartEx() for layer blending.

  4. Output the blended result to the LCD display device.

Example Usage

Compilation and Flashing

Switch to the example project directory and run the scons command to compile:

scons --board=sf32lb52-lchspi-ulp -j8

Execute the flashing command:

build_sf32lb52-lchspi-ulp_hcpu\uart_download.bat

Select the port as prompted for download:

please input the serial port num:6

Example Output Result Display:

Serial port window prints as shown: alt text Will display on the LCD screen as shown: alt text

Example Explanation

Key interfaces used:

Interface Name

Function Description

HAL_EZIP_Init()

Initialize EZIP module

HAL_EPIC_Init()

Initialize EPIC graphics controller

HAL_EPIC_LayerConfigInit()

Initialize layer configuration structure

HAL_EPIC_LayerSetDataOffset()

Set layer data offset (for cropping)

HAL_EPIC_FillStart()

Start color fill operation

HAL_EPIC_BlendStartEx()

Start multi-layer blending operation

Notes

Crop area settings need to be careful Default cropping behavior: If HAL_EPIC_LayerSetDataOffset() is not called, it defaults to cropping image data from the first address pointed to by the layer.data pointer, which is (0, 0) in this example.

Common issues:

If the fill area is not within the crop area, valid image data cannot be extracted, causing layer blending to fail. Example: If the fill area is (100~250, 100~200), but the crop area is (0~150, 0~100), then the actual cropped blending data will be empty. Solution:

  • Method 1: Adjust the fill area to be within the crop area.

  • Method 2: Call HAL_EPIC_LayerSetDataOffset(layer, x, y) to set the crop offset, note that the x/y passed should be target coordinates + layer.x_offset / layer.y_offset.