DMA2D (Chrom-ART Accelerator)

Transformation demonstration

Presentation

The DMA2D integration is the keystone to graphics potential of the STM32F429. Through a set of registers, it provides graphics  management features that include:

• handling of bitmap files (up to 32 bits per pixel),
• management of image overlays, with or without transparency/blending,
• handling of object display to include multiple objects and their positions, sizes and layering (Z-order).

The CircleOS provides a specific API for easily implement these features by integration of the DMA2D peripheral and SDRAM driver.
This API covers:

• Handling of bit maps (display, overlaying and moving)
• Using transparency (pixel-level, global and blending)
• Dynamic versus Read-Only objects
• Management of objects and touch sensing
• Use of layering (Z-order)

Take a look at this document for more information.

DMA2D transformation demonstration

 The DMA2D demonstration shows how to use the DMA2D tranformation functions provided by the CircleOS API's.

• DMA2D_ObjectTransform :  generic transform function used to copy, rotate, resize an object.
  This function takes every pixel of the SOURCE, and calculates its new value.
  Example :
  int fRot90X( int x, int y ) { return y; }
  int fRot90Y( int x, int y ) { return 48-x-1; }
• DMA2D_ObjectTransformReverse : generic transform function used to copy, rotate, resize, modify the color of an object....
  This function takes every pixel of the DESTINATION, and calculates its new value.
  Example:
  DMA2D_ObjectTransformReverse( obj_dest, obj_src, ColorInvertRB );
  where ColorInvertRB inverts red and blue colors of the object.

The application moves an object with 3 transformations :

• object size,
• object color,
• object orientation.

Screen shots

Notes :  

• The "Evo_Circle_STM3242x.elf", "FAT.elf" and "FAT_OP4.elf" files location depends on your Ride installation; delete them from the projet and add it back before building the project.
• This example runs only on STM32F429I platform.
• The screenshots have been made thanks to the "UTIL_SaveScreenBMP" API function.
• For more information about the CircleOS API's, see :   Circle OS Conception document