[Create Framebuffer Class]

framebuffer.cpp

@@ -0,0 +1,100 @@
+#include "framebuffer.hpp"
+#include <string>
+#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>
+
+Framebuffer::Framebuffer(std::string devicePath) {
+	char *devicePathCharArray = new char[devicePath.length()]();
+	for(int i = 0; i < (int) devicePath.length(); i++) {
+		devicePathCharArray[i] = devicePath[i];
+	}
+	this->devicePath = devicePathCharArray;
+}
+
+int Framebuffer::init() {
+	if(devicePath == NULL || isDeviceOpen) return -1;
+
+	device = open(devicePath, O_RDWR);
+
+	struct fb_var_screeninfo screeninfo;
+	ioctl(device, FBIOGET_VSCREENINFO, &screeninfo);
+
+	bitsPerPixel = screeninfo.bits_per_pixel;
+	if(bitsPerPixel != 32) {
+		printf("Colorscale: %i bits per pixel\n", bitsPerPixel);
+		printf("Change the colordepth to 32 bits per pixel\n");
+		close(device);
+		return -1;
+	}
+
+	width = screeninfo.xres;
+	height = screeninfo.yres;
+	bytesPerPixel = bitsPerPixel / 8;
+
+	if(sizeof(unsigned int) != bytesPerPixel) {
+		close(device);
+		return -1;
+	}
+
+	isDeviceOpen = true;
+
+	mmapData();
+
+	return 0;
+}
+
+int Framebuffer::getWidth() {
+	return width;
+}
+
+int Framebuffer::getHeight() {
+	return height;
+}
+
+int Framebuffer::getBytesPerPixel() {
+	return bytesPerPixel;
+}
+
+void Framebuffer::mmapData() {
+	data = (unsigned int*) mmap(0, width * height * bytesPerPixel, 
+															PROT_READ | PROT_WRITE, MAP_SHARED, device, 0);
+	isDataMapped = true;
+}
+
+int Framebuffer::setPixel(int x, int y, unsigned int color) {
+	if(isDataMapped)
+		data[y * width + x] = color;
+	else
+		return -1;
+	return 0;
+}
+
+int Framebuffer::clear(unsigned int color) {
+	for(int row = 0; row < height; row++) {
+		for(int column = 0; column < width; column++) {
+			int success = setPixel(column, row, color);
+			if(success != 0) return -1;
+		}
+	}
+
+	return 0;
+}
+
+void Framebuffer::munmapData() {
+	munmap(data, width * height * bytesPerPixel);
+	isDataMapped = false;
+}
+
+void Framebuffer::done() {
+	if(isDataMapped) munmapData();
+	if(isDeviceOpen) {
+		close(device);
+		isDeviceOpen = false;
+	}
+}

framebuffer.hpp

@@ -0,0 +1,30 @@
+#ifndef FRAMEBUFFER_H
+#define FRAMEBUFFER_H
+
+#include <string>
+
+const unsigned int COLOR_RED = 0xFFFF0000;
+const unsigned int COLOR_GREEN = 0xFF00FF00;
+const unsigned int COLOR_BLUE = 0xFF0000FF;
+
+class Framebuffer {
+	public:
+		Framebuffer(std::string devicePath);
+		int init();
+		int getWidth();
+		int getHeight();
+		int getBytesPerPixel();
+		int setPixel(int x, int y, unsigned int color);
+		int clear(unsigned int color);
+		void done();
+		void mmapData();
+		void munmapData();
+	private:
+		unsigned int *data;
+		int device, width, height, bitsPerPixel, bytesPerPixel;
+		bool isDataMapped = false;
+		bool isDeviceOpen = false;
+		const char *devicePath;
+};
+
+#endif

main.cpp

@@ -1,70 +1,48 @@
-#include <sys/types.h>
-#include <sys/stat.h>
-#include <sys/mman.h>
-#include <sys/ioctl.h>
-#include <fcntl.h>
-#include <linux/fb.h>
+#include "framebuffer.hpp"
 #include <unistd.h>
-#include <stdio.h>
+#include <signal.h>
 
-const unsigned int RED = 0xFFFF0000;
-const unsigned int GREEN = 0xFF00FF00;
-const unsigned int BLUE = 0xFF0000FF;
 const unsigned int SECOND = 1000000;
 
+Framebuffer fb{"/dev/fb0"};
 
-// 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);
+void exitHandler(int s) {
+	printf("Caught signal %d\n", s);
+	fb.done();
+	exit(-1);
 }
 
 int main() {
-	int width, height, bitspp, bytespp;
+	if(fb.init() != 0) return -1;
 
-	int fd = open("/dev/fb0", O_RDWR);
+	struct sigaction sigIntHandler;
 
-	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;
-	}
+	sigIntHandler.sa_handler = exitHandler;
+	sigemptyset(&sigIntHandler.sa_mask);
+	sigIntHandler.sa_flags = 0;
+	sigaction(SIGINT, &sigIntHandler, NULL);
 
 	int counter = 0;
-
 	while(true) {
-		unsigned int color = (counter == 0) ? RED : ((counter == 1) ? GREEN : BLUE);
-		clearFramebuffer(fd, width, height, bytespp, color);
+		unsigned int color = (counter == 0) ? COLOR_RED : 
+													((counter == 1) ? COLOR_GREEN : COLOR_BLUE);
+
+		int success = fb.clear(color);
+
+		if(success != 0) {
+			fb.done();
+			return -1;
+		}
+		
 		if(counter < 2)
 			counter++;
 		else
 			counter = 0;
+
 		usleep(SECOND);
 	}
 
-	close(fd);
+	fb.done();
 	
 	return 0;
 }

makefile

@@ -0,0 +1,20 @@
+CXX = g++
+
+CXXFLAGS = -std=c++11 -Wall
+
+TARGET = FramebufferFun
+
+SRCS = main.cpp framebuffer.cpp
+
+OBJS = $(SRCS:.cpp=.o)
+
+$(TARGET): $(OBJS)
+	$(CXX) $(CXXFLAGS) $(OBJS) -o $(TARGET)
+
+%.o: %.cpp
+	$(CXX) $(CXXFLAGS) -c $< -o $@
+
+clean:
+	rm -f $(OBJS) $(TARGET)
+
+.PHONY: clean