[RGB Framebuffer animation]

main.cpp

@@ -0,0 +1,70 @@
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <sys/mman.h>
+#include <sys/ioctl.h>
+#include <fcntl.h>
+#include <linux/fb.h>
+#include <unistd.h>
+#include <stdio.h>
+
+const unsigned int RED = 0xFFFF0000;
+const unsigned int GREEN = 0xFF00FF00;
+const unsigned int BLUE = 0xFF0000FF;
+const unsigned int SECOND = 1000000;
+
+
+// AARRGGBB
+void clearFramebuffer(int fd, int width, int height, int bytespp, unsigned int color) {
+	int row, col;
+	unsigned int *data;
+
+	data = (unsigned int*) mmap(0, width * height * bytespp, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0);
+
+	for(row = 0; row < height; row++)
+		for(col = 0; col < width; col++)
+			data[row * width + col] = color;
+
+	munmap(data, width * height * bytespp);
+}
+
+int main() {
+	int width, height, bitspp, bytespp;
+
+	int fd = open("/dev/fb0", O_RDWR);
+
+	struct fb_var_screeninfo screeninfo;
+	ioctl(fd, FBIOGET_VSCREENINFO, &screeninfo);
+
+	bitspp = screeninfo.bits_per_pixel;
+	if(bitspp != 32) {
+		printf("Farbaufloesung = %i Bits pro Pixel\n", bitspp);
+		printf("Bitte aendern Sie die Farbtiefe auf 32 Bits pro Pixel\n");
+		close(fd);
+		return 1;
+	}
+
+	width = screeninfo.xres;
+	height = screeninfo.yres;
+	bytespp = bitspp / 8;
+
+	if(sizeof(unsigned int) != bytespp) {
+		close(fd);
+		return 1;
+	}
+
+	int counter = 0;
+
+	while(true) {
+		unsigned int color = (counter == 0) ? RED : ((counter == 1) ? GREEN : BLUE);
+		clearFramebuffer(fd, width, height, bytespp, color);
+		if(counter < 2)
+			counter++;
+		else
+			counter = 0;
+		usleep(SECOND);
+	}
+
+	close(fd);
+	
+	return 0;
+}