Simple double buffer manager for STM32

main.c

static Screen *screen;

int main(void) {
	HAL_Init();
	SystemClock_Config();
	screen = ct_screen_init();

	while (1) {
		ct_screen_flip_buffers(screen);
		// put normal drawing code here...
	}
}

screen.c

// LCD Double Buffer manager for STM32
// @author toxi

#include <stdlib.h>
#include "screen.h"

Screen* ct_screen_init() {
	BSP_LCD_Init();
	Screen *screen = (Screen*) malloc(sizeof(Screen));
	screen->width = BSP_LCD_GetXSize();
	screen->height = BSP_LCD_GetYSize();
	screen->addr[0] = LCD_FB_START_ADDRESS;
	screen->addr[1] = LCD_FB_START_ADDRESS + screen->width * screen->height * 4;
	screen->front = 1;
	BSP_LCD_LayerDefaultInit(0, screen->addr[0]);
	BSP_LCD_LayerDefaultInit(1, screen->addr[1]);
	BSP_LCD_SetLayerVisible(0, DISABLE);
	BSP_LCD_SetLayerVisible(1, ENABLE);
	BSP_LCD_SelectLayer(0);
	return screen;
}

void ct_screen_flip_buffers(Screen *screen) {
  // wait for VSYNC
	while (!(LTDC->CDSR & LTDC_CDSR_VSYNCS));
	BSP_LCD_SetLayerVisible(screen->front, DISABLE);
	screen->front ^= 1;
	BSP_LCD_SetLayerVisible(screen->front, ENABLE);
	BSP_LCD_SelectLayer(ct_screen_backbuffer_id(screen));
}

uint32_t* ct_screen_backbuffer_ptr(Screen *screen) {
	return (uint32_t*)(screen->addr[ct_screen_backbuffer_id(screen)]);
}

screen.h

// LCD Double Buffer manager for STM32
// @author toxi

#pragma once

#include "stm32746g_discovery_lcd.h"

typedef struct {
	uint32_t addr[2];
	uint32_t width;
	uint32_t height;
	uint32_t front;
} Screen;

Screen* ct_screen_init();
void ct_screen_flip_buffers(Screen *screen);
uint32_t* ct_screen_backbuffer_ptr(Screen *screen);

inline uint32_t ct_screen_backbuffer_id(Screen *screen) {
	return 1 - screen->front;
}