C Modules¶

Principle¶

Several C modules implement the UI Pack’s Abstraction Layer APIs. Some are generic, and some are VEE Port dependent (more precisely: GPU-dependent). The generic modules provide header files to be extended by the specific modules. The generic C modules are available on the Central Repository and the specific C modules on the Developer Repository.

The following picture illustrates the available C modules, and the following chapters explain the aim and relations of each C module.

Note

It is a simplified view: all sources and headers files of each C module are not visible.

MicroUI C Modules¶

UI Pack¶

The UI Pack provides a header file to implement the MicroUI drawings: LLUI_PAINTER_impl.h. See UI Pack chapter to have more information.

The UI Pack and its header files are available on the Central Repository: https://repository.microej.com/modules/com/microej/pack/ui/ui-pack/.

C Module: MicroUI¶

This generic C module provides an implementation of all MicroUI Abstraction Layer APIs. This C module is mandatory and provides default implementations for:

LLUI_PAINTER_impl.h and LLDW_PAINTER_impl.h: see Abstraction Layer API (it manages the synchronization with the Graphics Engine and redirects all drawings to an implementation of ui_drawing.h),
Images heap allocator: see Images Heap,
LLUI_INPUT_IMPL_log_queue_xxx(): see Event Buffer.

See UI Pack chapter to have more information. This C module is available on the Central Repository: com.microej.clibrary.llimpl#microui.

C Module: MicroUI Over DMA2D¶

This C module is a specific implementation of the C module MicroUI over STM32 DMA2D (Chrom-ART Graphics Accelerator). It implements a set of drawings over the official Chrom-ART Graphics Accelerator API: ui_drawing_dma2d.c.

Accelerated Drawings¶

The following table describes the accelerated features:

Feature	Comment
Fill rectangle
Draw image	ARGB8888, RGB888, RGB565, ARGB1555, ARGB4444, A8, A4
Flush (copy)	Copy of data from back buffer to frame buffer

This C module is available on the Central Repository: com.microej.clibrary.llimpl#display-dma2d.

C Module: MicroUI Over VGLite¶

This C module is a specific implementation of the C module MicroUI over Vivante VGLite. It implements a set of drawings over the official Vivante VGLite library (that targets some GPU with vector graphics acceleration): ui_drawing_vglite.c.

This C module also provides a set of header files (and their implementations) to manipulate some MicroUI concepts over the VGLite library: image management, path format, etc.: ui_vglite.h and ui_drawing_vglite_path.h.

Options¶

This C module provides some drawing algorithms that are disabled by default.

The rendering time of a simple shape with the GPU (time in the VG-Lite library + GPU setup time + rendering time) is longer than with software rendering. To enable the hardware rendering for simple shapes, uncomment the definition of VGLITE_USE_GPU_FOR_SIMPLE_DRAWINGS in ui_vglite_configuration.h.
The rendering time of an RGB565 image into an RGB565 buffer without applying an opacity (alpha == 0xff) is longer than with software rendering (as this kind of drawing consists in performing a mere memory copy). To enable the hardware rendering for RGB565 images, uncomment the definition of VGLITE_USE_GPU_FOR_RGB565_IMAGES in ui_vglite_configuration.h.
ARGB8888, ARGB1555, and ARGB4444 transparent images may not be compatible with some revisions of the VG-Lite GPU. Older GPU revisions do not render transparent images correctly because the pre-multiplication of the pixel opacity is not propagated to the pixel color components. To force the hardware rendering for non-premultiplied transparent images when the VG-Lite GPU is not compatible, uncomment the definition of VGLITE_USE_GPU_FOR_TRANSPARENT_IMAGES in ui_vglite_configuration.h. Note that this limitation does not concern the VG-Lite GPU compatible with non-premultiplied transparent images and the A8/A4 formats.

Accelerated Drawings¶

The following table describes the accelerated features:

Feature	Comment
Draw line	Disabled by default (see above)
Fill rectangle	Disabled by default (see above)
Draw rounded rectangle	Disabled by default (see above)
Fill rounded rectangle
Draw circle arc	Disabled by default (see above)
Fill circle arc
Draw ellipse arc	Disabled by default (see above)
Fill ellipse arc
Draw ellipse arc	Disabled by default (see above)
Fill ellipse arc
Draw circle	Disabled by default (see above)
Fill circle
Draw image	ARGB8888_PRE, ARGB1555_PRE, ARGB4444_PRE, RGB565, A8, A4 ARGB8888, ARGB1555, ARGB4444 (see above)
Draw thick faded point	Only with fade <= 1
Draw thick faded line	Only with fade <= 1
Draw thick faded circle	Only with fade <= 1
Draw thick faded circle arc	Only with fade <= 1
Draw thick faded ellipse	Only with fade <= 1
Draw thick line
Draw thick circle
Draw thick circle arc
Draw thick ellipse
Draw flipped image	See draw image
Draw rotated image	See draw image
Draw scaled image	See draw image

This C module is available on the Developer Repository: com.microej.clibrary.llimpl#microui-vglite.

Compatibility With MCU i.MX RT595¶

The previous versions of the C Module Over VGLite included an implementation of the Low-Level API LLUI_DISPLAY_impl.h. This support has been extracted into a dedicated C Module since the version 7.0.0. The dedicated C Module is available on the Developer Repository: com.microej.clibrary.llimpl#microui-mimxrt595-evk.

Only the C Module com.microej.clibrary.llimpl#microui-vglite is useful to target the Vivante VG-Lite GPU to perform the MicroUI and MicroVG drawings. The C Module com.microej.clibrary.llimpl#microui-mimxrt595-evk only gives an example of an implementation compatible with the MCU i.MX RT595 MCU.

Note

For more information, see the migration notes.

C Module: MicroUI Over NemaGFX¶

This C module is a specific implementation of the C module MicroUI over Think Silicon NemaGFX. It implements a set of drawings over the official NemaGFX library (that targets some GPU with vector graphics acceleration): ui_drawing_nema.c.

Implementation¶

The MicroUI Graphics Engine waits the end of the asynchronous drawings (performed by the GPU). The VEE Port must unlock this waiting by using one of these two solutions:

Mode interrupt: the GPU interrupt routine has to call the function UI_DRAWING_NEMA_post_operation() (the GPU interrupt routine is often written in the same file than the implementation of nema_sys_init()).
Mode task: the VEE Port has to add a dedicated task that will wait the end of the drawings.

The mode interrupt is enabled by default. To use the mode task, comment the define NEMA_INTERRUPT_MODE in ui_drawing_nema_configuration.h

Note

Retrieve more details in the #define NEMA_INTERRUPT_MODE documentation.

Options¶

This C module provides some drawing algorithms that are disabled by default.

The rendering time of a simple shape with the GPU (time in the NemaGFX library + GPU setup time + rendering time) is longer than with software rendering. To enable the hardware rendering for simple shapes, uncomment the definition of ENABLE_SIMPLE_LINES in ui_drawing_nema_configuration.h.
To draw a shape, the GPU uses the commands list. For rectangular shapes (draw/fill rectangles and images), the maximum list size is fixed (around 300 bytes). For the other shapes (circle, etc.) the list increases according the shape size (dynamic shape): several blocks of 1024 bytes and 40 bytes are allocated and never freed. By default, the dynamic shapes are disabled and the software algorithms are used instead. To enable the hardware rendering for dynamic shapes, uncomment the definition of ENABLE_DYNAMIC_SHAPES in ui_drawing_nema_configuration.h.
Some GPU might not be able to render the images in specific memories. Comment the define ENABLE_IMAGE_ROTATION in ui_drawing_nema_configuration.h to not use the GPU to render the rotated images.

Accelerated Drawings¶

The following table describes the accelerated features:

Feature	Comment
Draw line
Draw horizontal line	Disabled by default (see above: ENABLE_SIMPLE_LINES)
Draw vertical line	Disabled by default (see above: ENABLE_SIMPLE_LINES)
Draw rectangle	Disabled by default (see above: ENABLE_SIMPLE_LINES)
Fill rectangle
Draw rounded rectangle	Disabled by default (see above: ENABLE_DYNAMIC_SHAPES)
Fill rounded rectangle	Disabled by default (see above: ENABLE_DYNAMIC_SHAPES)
Draw circle	Disabled by default (see above: ENABLE_DYNAMIC_SHAPES)
Fill circle	Disabled by default (see above: ENABLE_DYNAMIC_SHAPES)
Draw image	ARGB8888, RGB565, A8
Draw thick faded line	Only with fade <= 1
Draw thick faded circle	Only with fade <= 1, disabled by default (see above: ENABLE_DYNAMIC_SHAPES)
Draw thick line
Draw thick circle	Disabled by default (see above: ENABLE_DYNAMIC_SHAPES)
Draw rotated image	See draw image
Draw scaled image	See draw image

This C module is available on the Developer Repository: com.microej.clibrary.llimpl#microui-nemagfx.

Compatibility¶

The compatibility between the components (Packs, C modules, and Libraries) is described in the C Modules.