Simulation

Principle

The VG Pack embeds an implementation of the UI Pack’s Front Panel mock that implements the equivalent of the five embedded modules (Matrix, Path, Gradient, Image and Font). This implementation has to be extended to simulate the same characteristics and limitations as the embedded modules. The aim of this extension is to:

  • decode the images encoded for a specific GPU (see Image Generator)

  • simulate the limitations of the MicroVG implementation over a GPU (unsupported blend modes, MicroUI drawings in a BufferedVectorImage, etc.).

Default Extensions

Two extensions are available that simulate the Vivante VGLite (compatible with the C Module: MicroVG Over VGLite) and Think Silicon NemaVG (compatible with the C Module: MicroVG Over NemaVG) GPUs. To select one of them, set the right name (respectively vglite and nema) in the VEE Port configuration file (see Installation).

Custom Extension

Overview

A custom extension can be selected to simulate another GPU. This extension consists of the implementation of several interfaces and classes. In the VEE Port’s Front Panel project:

  1. Add the dependency:

    <dependency org="com.microej.pack.vg" name="vg-pack" rev="x.y.z">
   <artifact name="vg-frontpanel" type="jar"/>
</dependency>

    Where x.y.z is the VG Pack version used to build the VEE Port (minimum 1.6.0).

  2. Implement one or several interfaces / classes to simulate the embedded GPU (see next chapters).

  3. Rebuild the VEE Port.

Image Decoder

To decode the images generarated by the image generator, implement the interface ej.microvg.image.ImageDecoder in the VEE Port’s Front Panel project. The name of the class must be ej.microvg.image.[Prefix]ImageDecoder where [Prefix] is the name that will be set in the VEE Port configuration file (see Installation).

Note

This implementation is mandatory to allow the use of encoded images.

Display Drawer

This feature allows to simulate the same limitations of the GPU to draw the MicroVG drawings (path, gradient, blend modes, etc.) in the display buffer (and in the BufferedImage with same format than the display buffer).

Note

This implementation is optional; by default, all the MicroVG drawings are implemented.

  1. Extend the class ej.microvg.display.DisplayDrawer; the name of the class must be ej.microvg.display.[Prefix]DisplayDrawer where [Prefix] is the name that will be set in the VEE Port configuration file (see Installation).

  2. Override the method drawPath() to simulate some limitations.

Buffered Vector Image

On the embedded side, the MicroUI drawings (line, rectangle, etc.) must be explicitly implemented to be stored in a BufferedVectorImage (a drawing should not be stored if the GPU is not able to render it). The Front Panel extension allows to simulate the same limitations.

Note

This implementation is optional; by default, all the MicroUI drawings in a BufferedVectorImage are disabled (whereas all the MicroVG drawings are enabled).

The Front Panel extension already provides an engine that implements all MicroUI drawings in a BufferedVectorImage. Each drawing of this extension can be used independently to simulate the behavior of the embedded side.

  1. Implement the interface ej.microvg.bvi.BufferedVectorImageDrawer; the name of the class must be ej.microvg.bvi.[Prefix]BufferedVectorImageDrawer where [Prefix] is the name that will be set in the VEE Port configuration file (see Installation).

  2. Implement one or several MicroUI drawing methods.

  3. Call the corresponded engine’s drawing method, for instance: LLVGEngine.Instance.getBufferedVectorImageDrawer().fillRectangle(xxx).

Installation

Refer to the chapter Installation for more information about the front panel configuration.

Use

Launch a MicroVG application on the Simulator to run the Front Panel extension.