LVGLDriver< RGB_T > Class Template Reference

LVGLDriver is a helper class to initialize LVGL v9 with a TinyGPU Output driver. It sets up the display buffer and flush callback for LVGL. More...

#include <LVGLDriver.h>

Collaboration diagram for LVGLDriver< RGB_T >:

Public Member Functions
	LVGLDriver (DisplayDriver< RGB_T > &driver, size_t x, size_t y, size_t bufferSize=0)
bool	begin ()
void	end ()
void	delay (uint32_t ms)
void	setTouchDriver (TouchDriver &touch)
bool	hasTouchDriver () const
	Checks if a touch driver has been set for this LVGLDriver.
TouchDriver &	touchDriver ()
DisplayDriver< RGB_T > &	getDriver ()

Static Public Member Functions
static void	display (lv_display_t *disp, const lv_area_t *area, uint8_t *px_map)
static void	setGamma (float gammaR, float gammaG, float gammaB)

Protected Member Functions
lv_indev_t *	setupTouch ()
	Registers a touch driver with this LVGL display instance.
void	dumpBuffer (const uint8_t *data, size_t len)

Static Protected Member Functions
static uint32_t	my_tick (void)
static GammaTable &	gammaR_ ()
static GammaTable &	gammaG_ ()
static GammaTable &	gammaB_ ()
static void	convertBuffer (uint8_t *px_map, size_t pixelCount)

Protected Attributes
Vector< uint8_t >	buf_1
DisplayDriver< RGB_T > *	driver = nullptr
TouchDriver *	touch_driver = nullptr
lv_display_t *	disp = nullptr
size_t	disp_x = 0
size_t	disp_y = 0
size_t	dispBufferSize = 0

Detailed Description

template<typename RGB_T = RGB565>
class LVGLDriver< RGB_T >

LVGLDriver is a helper class to initialize LVGL v9 with a TinyGPU Output driver. It sets up the display buffer and flush callback for LVGL.

Template Parameters

RGB_T

The pixel format LVGL's rendered output is converted to before transmission. Defaults to RGB565, matching LVGL's own internal RGB565 color format (convertBuffer() below still has to undo RGB565's own byte-swapped storage - see RGB565.h - even in that default case).

Constructor & Destructor Documentation

LVGLDriver()

LVGLDriver ( DisplayDriver< RGB_T > &  driver, size_t  x, size_t  y, size_t  bufferSize = 0  )

inline

Member Function Documentation

begin()

bool begin ( )

inline

convertBuffer()

static void convertBuffer ( uint8_t *  px_map, size_t  pixelCount  )

inlinestaticprotected

Converts a buffer LVGL packed as (native-order) RGB565 into RGB_T's own byte layout, applying per-channel gamma correction (see setGamma()), in place. Each pixel is decoded with RGB565's semantics (what LVGL actually wrote), gamma corrected, and re-encoded via RGB_T::fromRGB(), so RGB_T's own compensation (if any) is genuinely applied regardless of how RGB_T's constructor happens to order its arguments.

delay()

void delay ( uint32_t  ms )

inline

display()

static void display ( lv_display_t *  disp, const lv_area_t *  area, uint8_t *  px_map  )

inlinestatic

dumpBuffer()

void dumpBuffer ( const uint8_t *  data, size_t  len  )

inlineprotected

end()

void end ( )

inline

gammaB_()

static GammaTable & gammaB_ ( )

inlinestaticprotected

gammaG_()

static GammaTable & gammaG_ ( )

inlinestaticprotected

gammaR_()

static GammaTable & gammaR_ ( )

inlinestaticprotected

getDriver()

DisplayDriver< RGB_T > & getDriver ( )

inline

Provides a reference to the underlying DisplayDriver instance used by this LVGLDriver (an SPI panel driver on ESP32, DisplayDriverSDL on desktop, or any other DisplayDriver<RGB_T> implementation).

hasTouchDriver()

bool hasTouchDriver ( ) const

inline

Checks if a touch driver has been set for this LVGLDriver.

my_tick()

static uint32_t my_tick ( void  )

inlinestaticprotected

setGamma()

static void setGamma ( float  gammaR, float  gammaG, float  gammaB  )

inlinestatic

Applies independent per-channel gamma correction to every color LVGL renders, before RGB_T's own field layout/compensation is applied. gammaR=gammaG=gammaB=1.0 (the default) applies no correction.

This is deliberately per-channel rather than one shared curve: some panels show a visible color tint in near-black/grey tones even with correct field compensation, because the panel's red/green/blue subpixels have different non-linear responses at low brightness. A single gamma applied equally to R, G and B can only ever change overall brightness - if R=G=B going in, the same curve on all three still gives R=G=B going out, so it mathematically cannot fix a hue tint in grey tones. Independent per-channel curves can, by deliberately un-balancing a grey input to counteract the panel's own imbalance. There's no single correct set of values for an unknown/ undocumented panel - try values on both sides of 1.0 per channel and compare on real hardware. See GammaTable.h.

setTouchDriver()

void setTouchDriver ( TouchDriver &  touch )

inline

Defines the touch driver to be used with LVGL. This is optional and can be set if a touch driver is available.

setupTouch()

lv_indev_t * setupTouch ( )

inlineprotected

Registers a touch driver with this LVGL display instance.

touchDriver()

TouchDriver & touchDriver ( )

inline

Provides a pointer to the touch driver, if one has been set. Returns nullptr if no touch driver is available.

Member Data Documentation

buf_1

Vector<uint8_t> buf_1

protected

disp

lv_display_t* disp = nullptr

protected

disp_x

size_t disp_x = 0

protected

disp_y

size_t disp_y = 0

protected

dispBufferSize

size_t dispBufferSize = 0

protected

driver

DisplayDriver<RGB_T>* driver = nullptr

protected

touch_driver

TouchDriver* touch_driver = nullptr

protected

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The documentation for this class was generated from the following file:

• src/TinyGPU/Integrations/LVGLDriver.h