STM32LTDC 2nd layer support with alpha

boards/base/STM32F429i-Discovery/board_STM32LTDC.h

@@ -23,6 +23,8 @@ static const SPIConfig spi_cfg = {
 	((1 << 3) & SPI_CR1_BR) | SPI_CR1_SSM | SPI_CR1_SSI | SPI_CR1_MSTR
 };
 
+#define ALLOW_2ND_LAYER		TRUE
+
 static const ltdcConfig driverCfg = {
 	240, 320,
 	10, 2,
@@ -37,15 +39,33 @@ static const ltdcConfig driverCfg = {
 		LTDC_PIXELFORMAT,					// fmt
 		0, 0,								// x, y
 		240, 320,							// cx, cy
-		LTDC_COLOR_FUCHSIA,					// defcolor
+		0x00000000,							// defcolor
-		0x980088,							// keycolor
+		0x000000,							// keycolor
 		LTDC_BLEND_FIX1_FIX2,				// blending
 		0,									// palette
 		0,									// palettelen
 		0xFF,								// alpha
 		LTDC_LEF_ENABLE						// flags
 	},
+#if ALLOW_2ND_LAYER
+	{										// Foreground layer config (if turned on)
+		(LLDCOLOR_TYPE *)(SDRAM_DEVICE_ADDR+(240 * 320 * LTDC_PIXELBYTES)), // Frame buffer address
+		240, 320,							// width, height
+		240 * LTDC_PIXELBYTES,				// pitch
+		LTDC_PIXELFORMAT,					// fmt
+		0, 0,								// x, y
+		240, 320,							// cx, cy
+		0x00000000,							// Default color (ARGB8888)
+		0x000000,							// Color key (RGB888)
+		LTDC_BLEND_MOD1_MOD2,				// Blending factors
+		0,									// Palette (RGB888, can be NULL)
+		0,									// Palette length
+		0xFF,								// Constant alpha factor
+		LTDC_LEF_ENABLE						// Layer configuration flags
+	}
+#else
 	LTDC_UNUSED_LAYER_CONFIG
+#endif
 };
 
 #include "ili9341.h"
@@ -146,12 +166,8 @@ static void Init9341(GDisplay *g) {
 }
 
 static void init_board(GDisplay *g) {
+	(void) g;
 
-	// As we are not using multiple displays we set g->board to NULL as we don't use it.
-	g->board = 0;
-
-	switch(g->controllerdisplay) {
-	case 0:											// Set up for Display 0
 	palSetPadMode(GPIOA, 9, PAL_MODE_ALTERNATE(7));		// UART_TX
 	palSetPadMode(GPIOA, 10, PAL_MODE_ALTERNATE(7));	// UART_RX
 	palSetPadMode(GPIOF, GPIOF_LCD_DCX, PAL_MODE_ALTERNATE(5));
@@ -183,8 +199,6 @@ static void init_board(GDisplay *g) {
 	spiStart(SPI_PORT, &spi_cfg);
 
 	Init9341(g);
-		break;
-	}
 }
 
 static GFXINLINE void post_init_board(GDisplay *g) {

boards/base/STM32F439i-Eval/CubeHal/board_STM32LTDC.h

@@ -17,6 +17,8 @@
 #include "stm32f4xx_hal.h"
 #include "stm324x9i_eval_sdram.h"
 
+#define ALLOW_2ND_LAYER		TRUE
+
 // Panel parameters
 // This panel is a AMPIRE640480 panel.
 
@@ -35,8 +37,8 @@ static const ltdcConfig driverCfg = {
 		LTDC_PIXELFORMAT,					// Pixel format
 		0, 0,								// Start pixel position (x, y)
 		640, 480,							// Size of virtual layer (cx, cy)
-		LTDC_COLOR_FUCHSIA,					// Default color (ARGB8888)
+		0x00000000,							// Default color (ARGB8888)
-		0x980088,							// Color key (RGB888)
+		0x000000,							// Color key (RGB888)
 		LTDC_BLEND_FIX1_FIX2,				// Blending factors
 		0,									// Palette (RGB888, can be NULL)
 		0,									// Palette length
@@ -44,7 +46,25 @@ static const ltdcConfig driverCfg = {
 		LTDC_LEF_ENABLE						// Layer configuration flags
 	},
 
-	LTDC_UNUSED_LAYER_CONFIG				// Foreground layer config
+#if ALLOW_2ND_LAYER
+	{										// Foreground layer config (if turned on)
+		(LLDCOLOR_TYPE *)(SDRAM_DEVICE_ADDR+(640 * 480 * LTDC_PIXELBYTES)), // Frame buffer address
+		640, 480,							// Width, Height (pixels)
+		640 * LTDC_PIXELBYTES,				// Line pitch (bytes)
+		LTDC_PIXELFORMAT,					// Pixel format
+		0, 0,								// Start pixel position (x, y)
+		640, 480,							// Size of virtual layer (cx, cy)
+		0x00000000,							// Default color (ARGB8888)
+		0x000000,							// Color key (RGB888)
+		LTDC_BLEND_MOD1_MOD2,				// Blending factors
+		0,									// Palette (RGB888, can be NULL)
+		0,									// Palette length
+		0xFF,								// Constant alpha factor
+		LTDC_LEF_ENABLE						// Layer configuration flags
+	}
+#else
+	LTDC_UNUSED_LAYER_CONFIG
+#endif
 };
 
 // LCD Clock values
@@ -113,11 +133,7 @@ static void configureLcdPins(void)
 
 static GFXINLINE void init_board(GDisplay* g)
 {
-	// As we are not using multiple displays we set g->board to NULL as we don't use it
+	(void) g;
-	g->board = 0;
-
-	switch(g->controllerdisplay) {
-		case 0:
 
 	// Set LCD pixel clock rate
 	configureLcdClock();
@@ -127,9 +143,6 @@ static GFXINLINE void init_board(GDisplay* g)
 
 	// Initialise the SDRAM
 	BSP_SDRAM_Init();
-
-		break;
-	}
 }
 
 static GFXINLINE void post_init_board(GDisplay* g)

boards/base/STM32F469i-Discovery/board_STM32LTDC.h

@@ -27,6 +27,8 @@
   static DSI_VidCfgTypeDef hdsivideo_handle;
   DSI_HandleTypeDef hdsi_eval;
 
+#define ALLOW_2ND_LAYER		FALSE			// Do we really have the RAM bandwidth for this?
+
 // Panel parameters
 // This panel is a KoD KM-040TMP-02-0621 DSI LCD Display.
 
@@ -45,8 +47,8 @@ static const ltdcConfig driverCfg = {
 		LTDC_PIXELFORMAT,					// Pixel format
 		0, 0,								// Start pixel position (x, y)
 		800, 480,							// Size of virtual layer (cx, cy)
-		LTDC_COLOR_FUCHSIA,					// Default color (ARGB8888)
+		0x00000000,							// Default color (ARGB8888)
-		0x980088,							// Color key (RGB888)
+		0x000000,							// Color key (RGB888)
 		LTDC_BLEND_FIX1_FIX2,				// Blending factors
 		0,									// Palette (RGB888, can be NULL)
 		0,									// Palette length
@@ -54,16 +56,32 @@ static const ltdcConfig driverCfg = {
 		LTDC_LEF_ENABLE						// Layer configuration flags
 	},
 
-	LTDC_UNUSED_LAYER_CONFIG				// Foreground layer config
+#if ALLOW_2ND_LAYER
+	{										// Foreground layer config (if turned on)
+		(LLDCOLOR_TYPE *)(SDRAM_DEVICE_ADDR+(800 * 480 * LTDC_PIXELBYTES)), // Frame buffer address
+		800, 480,							// Width, Height (pixels)
+		800 * LTDC_PIXELBYTES,				// Line pitch (bytes)
+		LTDC_PIXELFORMAT,					// Pixel format
+		0, 0,								// Start pixel position (x, y)
+		800, 480,							// Size of virtual layer (cx, cy)
+		0x00000000,							// Default color (ARGB8888)
+		0x000000,							// Color key (RGB888)
+		LTDC_BLEND_MOD1_MOD2,				// Blending factors
+		0,									// Palette (RGB888, can be NULL)
+		0,									// Palette length
+		0xFF,								// Constant alpha factor
+		LTDC_LEF_ENABLE						// Layer configuration flags
+	}
+#else
+	LTDC_UNUSED_LAYER_CONFIG
+#endif
 };
 
 /* Display timing */
 #define KoD_FREQUENCY_DIVIDER 7
 
 static GFXINLINE void init_board(GDisplay *g) {
-
+	(void) g;
-	// As we are not using multiple displays we set g->board to NULL as we don't use it
-	g->board = 0;
 
 	DSI_PLLInitTypeDef dsiPllInit;
   	DSI_PHY_TimerTypeDef  PhyTimings;
@@ -241,12 +259,16 @@ static GFXINLINE void init_board(GDisplay *g) {
     /* Initialize the SDRAM */
     BSP_SDRAM_Init();
   #endif /* DATA_IN_ExtSDRAM */
+
 }
 
 static GFXINLINE void post_init_board(GDisplay* g)
 {
 	(void)g;
 
+	if (g->controllerdisplay)
+		return;
+
   	/* Initialize the font */
   	BSP_LCD_SetFont(&LCD_DEFAULT_FONT);
 
@@ -259,14 +281,6 @@ static GFXINLINE void post_init_board(GDisplay* g)
   	*  depending on configuration set in 'hdsivideo_handle'.
   	*/
   	OTM8009A_Init(OTM8009A_FORMAT_RGB888, OTM8009A_ORIENTATION_LANDSCAPE);
-  
-	/***********************End OTM8009A Initialization****************************/ 
-
-	// ------------------------------------------------------------------------
-
-	//BSP_LCD_LayerDefaultInit(LTDC_ACTIVE_LAYER_BACKGROUND, LCD_FB_START_ADDRESS);
-	//BSP_LCD_SelectLayer(LTDC_ACTIVE_LAYER_BACKGROUND);
-	//BSP_LCD_SetLayerVisible(LTDC_ACTIVE_LAYER_FOREGROUND, DISABLE);
 }
 
 static GFXINLINE void set_backlight(GDisplay* g, uint8_t percent)

boards/base/STM32F746-Discovery/board_STM32LTDC.h

@@ -36,6 +36,8 @@
 	#define AFRH	AFR[1]
 #endif
 
+#define ALLOW_2ND_LAYER		TRUE
+
 static const ltdcConfig driverCfg = {
 	480, 272,								// Width, Height (pixels)
 	41, 10,									// Horizontal, Vertical sync (pixels)
@@ -51,8 +53,8 @@ static const ltdcConfig driverCfg = {
 		LTDC_PIXELFORMAT,					// Pixel format
 		0, 0,								// Start pixel position (x, y)
 		480, 272,							// Size of virtual layer (cx, cy)
-		LTDC_COLOR_FUCHSIA,					// Default color (ARGB8888)
+		0x00000000,							// Default color (ARGB8888)
-		0x980088,							// Color key (RGB888)
+		0x000000,							// Color key (RGB888)
 		LTDC_BLEND_FIX1_FIX2,				// Blending factors
 		0,									// Palette (RGB888, can be NULL)
 		0,									// Palette length
@@ -60,7 +62,25 @@ static const ltdcConfig driverCfg = {
 		LTDC_LEF_ENABLE						// Layer configuration flags
 	},
 
-	LTDC_UNUSED_LAYER_CONFIG				// Foreground layer config
+#if ALLOW_2ND_LAYER
+	{										// Foreground layer config (if turned on)
+		(LLDCOLOR_TYPE *)(SDRAM_DEVICE_ADDR+(480 * 272 * LTDC_PIXELBYTES)), // Frame buffer address
+		480, 272,							// Width, Height (pixels)
+		480 * LTDC_PIXELBYTES,				// Line pitch (bytes)
+		LTDC_PIXELFORMAT,					// Pixel format
+		0, 0,								// Start pixel position (x, y)
+		480, 272,							// Size of virtual layer (cx, cy)
+		0x00000000,							// Default color (ARGB8888)
+		0x000000,							// Color key (RGB888)
+		LTDC_BLEND_MOD1_MOD2,				// Blending factors
+		0,									// Palette (RGB888, can be NULL)
+		0,									// Palette length
+		0xFF,								// Constant alpha factor
+		LTDC_LEF_ENABLE						// Layer configuration flags
+	}
+#else
+	LTDC_UNUSED_LAYER_CONFIG
+#endif
 };
 
 static void configureLcdPins(void) {
@@ -374,12 +394,7 @@ static void configureLcdPins(void) {
 }
 
 static GFXINLINE void init_board(GDisplay *g) {
-
+	(void) g;
-	// As we are not using multiple displays we set g->board to NULL as we don't use it
-	g->board = 0;
-
-	switch(g->controllerdisplay) {
-	case 0:
 
 	// Set pin directions
 	configureLcdPins();
@@ -439,12 +454,6 @@ static GFXINLINE void init_board(GDisplay *g) {
 
 	// Initialise the SDRAM
 	BSP_SDRAM_Init();
-
-		// Clear the SDRAM
-		//memset((void *)SDRAM_BANK_ADDR, 0, 0x400000);
-
-		break;
-	}
 }
 
 static GFXINLINE void post_init_board(GDisplay* g) {

changelog.txt

@@ -51,6 +51,15 @@ FEATURE:	Added gwinTextEditSendKey() and gwinTextEditSendSpecialKey()
 FEATURE:	Implemented the JPG image decoder
 FEATURE:	Added SSD1322 driver
 FEATURE:    Added support for Zephyr operating system
+FEATURE:	STM32LTDC driver now supports using both layers as seperate displays. The 2nd display is the foreground layer
+CHANGE:		STM32LTDC driver now uses RGB888 pixel format by default
+FEATURE:	Added GDISP_LTDC_USE_RGB565 config variable to force STM32LTDC driver to use RGB565 pixel format
+FEATURE:	The STM32LTDC 2nd display (the foreground layer) supports alpha.
+FEATURE:	The STM32 board files for known boards have been updated to contain support for the 2nd layer.
+FEATURE:	Added AHTML2COLOR() and ARGB2COLOR() to support alpha. This is currently only supported for the RGB888 pixel format.
+FEATURE:	Added the new color GFXTRANSPARENT - only available for RGB888 pixel format on alpha capable displays.
+NOTE:		Alpha support in RGB888 requies an alpha capable display (STM32LTDC 2nd display only currently)
+NOTE:		Alpha support in RGB888 is NOT the standard ARGB8888 format. Only use AHTML2COLOR() and ARGB2COLOR() to create alpha colors.
 
 
 *** Release 2.7 ***

demos/modules/gdisp/multiple_displays/gfxconf.h

@@ -84,7 +84,7 @@
 	//#define GDISP_PIXELFORMAT     GDISP_PIXELFORMAT_RGB888
 
 #elif !defined(GDISP_TOTAL_DISPLAYS) && (!defined(GDISP_PIXELFORMAT) || !defined(GDISP_DRIVER_LIST))
-	#error "gfxconf.h: You have not defined multiple displays properly. Try defining GDISP_TOTAL_DISPLAY or, GDISP_PIXELFORMAT and GDISP_DRIVER_LIST in your makefile"
+	#error "gfxconf.h: You have not defined multiple displays properly. Try defining GDISP_TOTAL_DISPLAYS or, GDISP_PIXELFORMAT and GDISP_DRIVER_LIST in your makefile"
 #endif
 
 /*

drivers/gdisp/STM32LTDC/board_STM32LTDC_template.h

@@ -8,6 +8,8 @@
 #ifndef _GDISP_LLD_BOARD_H
 #define _GDISP_LLD_BOARD_H
 
+#define ALLOW_2ND_LAYER		TRUE
+
 static const ltdcConfig driverCfg = {
 	480, 272,								// Width, Height (pixels)
 	41, 10,									// Horizontal, Vertical sync (pixels)
@@ -23,8 +25,8 @@ static const ltdcConfig driverCfg = {
 		LTDC_PIXELFORMAT,					// Pixel format
 		0, 0,								// Start pixel position (x, y)
 		480, 272,							// Size of virtual layer (cx, cy)
-		LTDC_COLOR_FUCHSIA,					// Default color (ARGB8888)
+		0x00000000,							// Default color (ARGB8888)
-		0x980088,							// Color key (RGB888)
+		0x000000,							// Color key (RGB888)
 		LTDC_BLEND_FIX1_FIX2,				// Blending factors
 		0,									// Palette (RGB888, can be NULL)
 		0,									// Palette length
@@ -32,28 +34,47 @@ static const ltdcConfig driverCfg = {
 		LTDC_LEF_ENABLE						// Layer configuration flags
 	},
 
-	LTDC_UNUSED_LAYER_CONFIG				// Foreground layer config
+#if ALLOW_2ND_LAYER
+	{										// Foreground layer config (if turned on)
+		(LLDCOLOR_TYPE *)(SDRAM_DEVICE_ADDR+(480 * 272 * LTDC_PIXELBYTES)), // Frame buffer address
+		480, 272,							// Width, Height (pixels)
+		480 * LTDC_PIXELBYTES,				// Line pitch (bytes)
+		LTDC_PIXELFORMAT,					// Pixel format
+		0, 0,								// Start pixel position (x, y)
+		480, 272,							// Size of virtual layer (cx, cy)
+		0x00000000,							// Default color (ARGB8888)
+		0x000000,							// Color key (RGB888)
+		LTDC_BLEND_MOD1_MOD2,				// Blending factors
+		0,									// Palette (RGB888, can be NULL)
+		0,									// Palette length
+		0xFF,								// Constant alpha factor
+		LTDC_LEF_ENABLE						// Layer configuration flags
+	}
+#else
+	LTDC_UNUSED_LAYER_CONFIG
+#endif
 };
 
 static GFXINLINE void init_board(GDisplay* g) {
-
+	// This is function only called once with the display for the background layer.
-	// As we are not using multiple displays we set g->board to NULL as we don't use it.
+	(void)g;
-	g->board = 0;
-
-	switch(g->controllerdisplay) {
-	case 0:											// Set up for Display 0
-		// Your init here
-		break;
-	}
 }
 
 static GFXINLINE void post_init_board(GDisplay* g)
 {
+	// This is function may be called twice - once for the background display and once
+	// for the foreground display.
+	// Note: It doesn't get called for the foreground display unless gfxconf.h has been
+	//		setup for two displays on this controller.
 	(void)g;
 }
 
 static GFXINLINE void set_backlight(GDisplay* g, uint8_t percent)
 {
+	// This is function may be called with the display for either the foreground
+	// or the background layer.
+	// Note: It can't be called for the foreground display unless gfxconf.h has been
+	//		setup for two displays on this controller.
 	(void)g;
 	(void)percent;
 }

drivers/gdisp/STM32LTDC/gdisp_lld_STM32LTDC.c

@@ -99,13 +99,15 @@ typedef struct ltdcConfig {
 /* Driver local routines.                                                    */
 /*===========================================================================*/
 
-#define PIXIL_POS(g, x, y)		((y) * driverCfg.bglayer.pitch + (x) * LTDC_PIXELBYTES)
+#define PIXIL_POS(g, x, y)		((y) * ((ltdcLayerConfig *)g->priv)->pitch + (x) * LTDC_PIXELBYTES)
-#define PIXEL_ADDR(g, pos)		((LLDCOLOR_TYPE *)((uint8_t *)driverCfg.bglayer.frame+pos))
+#define PIXEL_ADDR(g, pos)		((LLDCOLOR_TYPE *)((uint8_t *)((ltdcLayerConfig *)g->priv)->frame+pos))
 
 /*===========================================================================*/
 /* Driver exported functions.                                                */
 /*===========================================================================*/
 
+static const ltdcLayerConfig layerOff = LTDC_UNUSED_LAYER_CONFIG;
+
 static void _ltdc_reload(void) {
 	LTDC->SRCR |= LTDC_SRCR_IMR;
 	while (LTDC->SRCR & (LTDC_SRCR_IMR | LTDC_SRCR_VBR))
@@ -210,7 +212,7 @@ static void _ltdc_init(void) {
 	_ltdc_layer_init(LTDC_Layer1, &driverCfg.bglayer);
 
 	// Load the foreground layer
-	_ltdc_layer_init(LTDC_Layer2, &driverCfg.fglayer);
+	_ltdc_layer_init(LTDC_Layer2, &layerOff);
 
 	// Interrupt handling
 	// Possible flags - LTDC_IER_RRIE, LTDC_IER_LIE, LTDC_IER_FUIE, LTDC_IER_TERRIE etc
@@ -227,6 +229,8 @@ LLDSPEC bool_t gdisp_lld_init(GDisplay* g) {
 	g->priv = 0;
 	g->board = 0;
 
+	switch(g->controllerdisplay) {
+	case 0:			// Display 0 is the background layer
 		// Init the board
 		init_board(g);
 
@@ -238,15 +242,42 @@ LLDSPEC bool_t gdisp_lld_init(GDisplay* g) {
 			dma2d_init();
 		#endif
 
+		if (!(driverCfg.bglayer.layerflags & LTDC_LEF_ENABLE))
+			return FALSE;
+
+		g->priv = (void *)&driverCfg.bglayer;
+
 	    // Finish Init the board
 	    post_init_board(g);
 
 		// Turn on the back-light
 		set_backlight(g, GDISP_INITIAL_BACKLIGHT);
 
+		break;
+
+	case 1:			// Display 1 is the foreground layer
+
+		if (!(driverCfg.fglayer.layerflags & LTDC_LEF_ENABLE))
+			return FALSE;
+
+		// Load the foreground layer
+		_ltdc_layer_init(LTDC_Layer2, &driverCfg.fglayer);
+		_ltdc_reload();
+
+		g->priv = (void *)&driverCfg.fglayer;
+
+	    // Finish Init the board
+	    post_init_board(g);
+
+		break;
+
+	default:		// There is only 1 LTDC in the CPU and only the 2 layers in the LTDC.
+		return FALSE;
+	}
+
 	// Initialise the GDISP structure
-	g->g.Width = driverCfg.bglayer.width;
+	g->g.Width = ((ltdcLayerConfig *)g->priv)->width;
-	g->g.Height = driverCfg.bglayer.height;
+	g->g.Height = ((ltdcLayerConfig *)g->priv)->height;
 	g->g.Orientation = GDISP_ROTATE_0;
 	g->g.Powermode = powerOn;
 	g->g.Backlight = GDISP_INITIAL_BACKLIGHT;
@@ -282,7 +313,14 @@ LLDSPEC void gdisp_lld_draw_pixel(GDisplay* g) {
 		while(DMA2D->CR & DMA2D_CR_START);
 	#endif
 
+	#if GDISP_LLD_PIXELFORMAT == GDISP_PIXELFORMAT_RGB888
+		// As we don't support ARGB pixel types in uGFX yet we will
+		// use RGB with an inverted alpha value for compatibility
+		// ie. 0x00FFFFFF is fully opaque white, 0xFFFFFFFF is fully transparent white
+		PIXEL_ADDR(g, pos)[0] = gdispColor2Native(g->p.color) ^ 0xFF000000;
+	#else
 		PIXEL_ADDR(g, pos)[0] = gdispColor2Native(g->p.color);
+	#endif
 }
 
 LLDSPEC	color_t gdisp_lld_get_pixel_color(GDisplay* g) {
@@ -313,7 +351,14 @@ LLDSPEC	color_t gdisp_lld_get_pixel_color(GDisplay* g) {
 		while(DMA2D->CR & DMA2D_CR_START);
 	#endif
 
+	#if GDISP_LLD_PIXELFORMAT == GDISP_PIXELFORMAT_RGB888
+		// As we don't support ARGB pixel types in uGFX yet we will
+		// use RGB with an inverted alpha value for compatibility
+		// ie. 0x00FFFFFF is fully opaque white, 0xFFFFFFFF is fully transparent white
+		color = PIXEL_ADDR(g, pos)[0] ^ 0xFF000000;
+	#else
 		color = PIXEL_ADDR(g, pos)[0];
+	#endif
 
 	return gdispNative2Color(color);
 }
@@ -321,19 +366,6 @@ LLDSPEC	color_t gdisp_lld_get_pixel_color(GDisplay* g) {
 #if GDISP_NEED_CONTROL
 	LLDSPEC void gdisp_lld_control(GDisplay* g) {
 		switch(g->p.x) {
-		case GDISP_CONTROL_POWER:
-			if (g->g.Powermode == (powermode_t)g->p.ptr)
-				return;
-			switch((powermode_t)g->p.ptr) {
-			case powerOff: case powerOn: case powerSleep: case powerDeepSleep:
-				// TODO
-				break;
-			default:
-				return;
-			}
-			g->g.Powermode = (powermode_t)g->p.ptr;
-			return;
-
 		case GDISP_CONTROL_ORIENTATION:
 			if (g->g.Orientation == (orientation_t)g->p.ptr)
 				return;
@@ -369,12 +401,6 @@ LLDSPEC	color_t gdisp_lld_get_pixel_color(GDisplay* g) {
 			set_backlight(g, (unsigned)g->p.ptr);
 			g->g.Backlight = (unsigned)g->p.ptr;
 			return;
-
-		case GDISP_CONTROL_CONTRAST:
-			if ((unsigned)g->p.ptr > 100) g->p.ptr = (void *)100;
-			// TODO
-			g->g.Contrast = (unsigned)g->p.ptr;
-			return;
 		}
 	}
 #endif
@@ -406,9 +432,6 @@ LLDSPEC	color_t gdisp_lld_get_pixel_color(GDisplay* g) {
 		uint32_t lineadd;
 		uint32_t shape;
 
-		// Wait until DMA2D is ready
-		while(DMA2D->CR & DMA2D_CR_START);
-
 		#if GDISP_NEED_CONTROL
 			switch(g->g.Orientation) {
 			case GDISP_ROTATE_0:
@@ -439,11 +462,22 @@ LLDSPEC	color_t gdisp_lld_get_pixel_color(GDisplay* g) {
 			shape = (g->p.cx << 16) | (g->p.cy);
 		#endif
 
+		// Wait until DMA2D is ready
+		while(DMA2D->CR & DMA2D_CR_START);
+
 		// Start the DMA2D
 		DMA2D->OMAR = (uint32_t)PIXEL_ADDR(g, pos);
 		DMA2D->OOR = lineadd;
 		DMA2D->NLR = shape;
+		#if GDISP_LLD_PIXELFORMAT == GDISP_PIXELFORMAT_RGB888
+			// As we don't support ARGB pixel types in uGFX yet we will
+			// use RGB with an inverted alpha value for compatibility
+			// ie. 0x00FFFFFF is fully opaque white, 0xFFFFFFFF is fully transparent white
+			DMA2D->OCOLR = (uint32_t)(gdispColor2Native(g->p.color)) ^ 0xFF000000;
+		#else
 			DMA2D->OCOLR = (uint32_t)(gdispColor2Native(g->p.color));
+		#endif
+		;
 		DMA2D->CR = DMA2D_CR_MODE_R2M | DMA2D_CR_START;
 	}
 

drivers/gdisp/STM32LTDC/gdisp_lld_config.h

@@ -21,8 +21,15 @@
 
 // Both these pixel formats are supported - pick one.
 // RGB565 obviously is faster and uses less RAM but with lower color resolution than RGB888
+
+#if defined(GDISP_LTDC_USE_RGB565) && GDISP_LTDC_USE_RGB565
 	#define GDISP_LLD_PIXELFORMAT			GDISP_PIXELFORMAT_RGB565
-//#define GDISP_LLD_PIXELFORMAT				GDISP_PIXELFORMAT_RGB888
+	#if GDISP_TOTAL_DISPLAYS > 1
+		#error "LTDC: You must use RGB888 pixel format with LTDC when using dual layers as only RGB888 currently supports using alpha"
+	#endif
+#else
+	#define GDISP_LLD_PIXELFORMAT			GDISP_PIXELFORMAT_RGB888
+#endif
 
 
 /*===========================================================================*/
@@ -35,9 +42,12 @@
 
 	// Accelerated bitfills are also possible but only for GDISP_ROTATE_0
 	//	and if no color translation is required (for now)
-	#if !GDISP_NEED_CONTROL && GDISP_PIXELFORMAT == GDISP_LLD_PIXELFORMAT
+	// Oops - this is not working and adds little performance benefit
- 		#define GDISP_HARDWARE_BITFILLS	TRUE
+	//	so we will just disable it for the near future.
-	#endif
+//	#if !GDISP_NEED_CONTROL && !defined(GDISP_PIXELFORMAT)
+// 		#define GDISP_HARDWARE_BITFILLS	TRUE
+//	#endif
+
 #endif /* GDISP_USE_DMA2D */
 
 #endif	/* GFX_USE_GDISP */

src/gdisp/gdisp_colors.h

@@ -328,6 +328,13 @@ typedef uint16_t	colorformat;
 	#endif
 	#define HTML2COLOR(h)		((COLOR_TYPE)(HTML2COLOR_R(h) | HTML2COLOR_G(h) | HTML2COLOR_B(h)))
 
+	// Special hack to allow alpha on RGB888
+	#if GDISP_PIXELFORMAT == GDISP_PIXELFORMAT_RGB888
+		#define GFXTRANSPARENT		(0xFF000000)
+		#define AHTML2COLOR(h)		((h) ^ 0xFF000000)
+ 		#define ARGB2COLOR(a,r,g,b)	((((COLOR_TYPE)(((a) ^ 0xFF) & 0xFF)) << 24) | RGB2COLOR_R(r) | RGB2COLOR_G(g) | RGB2COLOR_B(b))
+	#endif
+
 //-------------------------
 //	Gray-scale color system
 //-------------------------