C

Stm32F7::Configuration Namespace

namespace Stm32F7::Configuration

Namespace for STM32F7 Configuration functions. More...

Header: #include <Configuration>

Classes

(since Qt Quick Ultralite (Platform) 1.9) struct Config

Types

(since Qt Quick Ultralite (Platform) 2.1) enum LayerType { Sprite, Rle }

Functions

`(since Qt Quick Ultralite (Platform) 1.9)` Tvii::Configuration::Config	configForOTFLayer(uint32_t platformId)
`(since Qt Quick Ultralite (Platform) 1.9)` Tvii::Configuration::Config	defaultConfigForOTFLayer()
bool	delayDrawingDuringDsiFlush()
`(since Qt Quick Ultralite (Platform) 2.1)` Rh850::Configuration::LayerType	layerType(int layerIndex)
`(since Qt Quick Ultralite (Platform) 1.9)` void	setConfigForOTFLayer(uint32_t platformId, uint16_t copses, uint32_t fifo, uint32_t lines)
void	setDelayDrawingDuringDsiFlush(bool enable)
`(since Qt Quick Ultralite (Platform) 2.1)` void	setLayerType(int layerIndex, Rh850::Configuration::LayerType layerType)

Detailed Description

Function Documentation

bool delayDrawingDuringDsiFlush()

Returns whether drawing waits for the previous frame to finish being sent to the display.

See also setDelayDrawingDuringDsiFlush().

void setDelayDrawingDuringDsiFlush(bool enable)

When enable is true, drawing waits for the previous frame to finish being sent to the display, trading frame rate for a tear-free screen. It is false by default and can be changed at any time.

A frame is sent to the display by hardware reading it out of SDRAM. An application that takes longer to draw a frame than the display takes to refresh is still drawing while that read runs, and the two compete for the bus, which can leave part of the screen showing the previous frame. Enabling this keeps them apart, so a frame costs the drawing plus the transfer rather than whichever of the two is longer.

Giving the glyph caches internal memory removes the same contention without costing frame rate, and is worth trying first. See STM32F769I Discovery Kit for both remedies and the measured difference between them.

See also delayDrawingDuringDsiFlush().

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