Matrix

Principle

The Matrix module contains the C part of the MicroVG implementation, which manages arithmetics matrices. This module is composed of only one element: an implementation of Abstraction Layer APIs to create and manipulate the matrices.

Functional Description

The Matrix module implements the framework of the MicroVG Matrix. It provides Abstraction Layer APIs that manipulate the matrices: fill an identity matrix, do a translation, a rotation, or a scaling and concatenate two matrices.

A matrix is a 3x3 matrix, and its elements are encoded in float (32-bit values):

  • matrix_memory[0] = matrix[0][0];

  • matrix_memory[1] = matrix[0][1];

  • matrix_memory[2] = matrix[0][2];

  • matrix_memory[3] = matrix[1][0];

  • matrix_memory[4] = matrix[1][1];

  • matrix_memory[5] = matrix[1][2];

  • matrix_memory[6] = matrix[2][0];

  • matrix_memory[7] = matrix[2][1];

  • matrix_memory[8] = matrix[2][2];

The buffer where the matrix is encoded is stored in the Java heap.

Abstraction Layer API

The Abstraction Layer APIs that have to be implemented are listed in the header file LLVG_MATRIX_impl.h (see LLVG_MATRIX: Matrix):

MicroVG Matrix Abstraction Layer

Matrix Abstraction Layer API

  • MicroVG library calls the BSP functions through the header file LLVG_MATRIX_impl.h.

  • The C module MicroVG provides a default implementation of this header file: LLVG_MATRIX_impl.c.

  • This file is automatically copied in the BSP project when fetching the C module during the VEE Port build.

Use

The MicroVG Matrix APIs are available in the class ej.microvg. Matrix.