added multi-monitor support

driver-uinput/Makefile

@@ -1,2 +1,2 @@
-
-networktablet : networktablet.c protocol.h
+export CC=c99
+networktablet : networktablet.c protocol.h -lX11 -lXrandr 

driver-uinput/networktablet.c

@@ -10,8 +10,11 @@
 #include <arpa/inet.h>
 #include <linux/input.h>
 #include <linux/uinput.h>
+#include <X11/Xlib.h>
+#include <dirent.h>
 #include "protocol.h"
-
+#include <X11/extensions/Xrandr.h>
+#include <getopt.h>
 #define die(str, args...) { \
 	perror(str); \
 	exit(EXIT_FAILURE); \
@@ -19,7 +22,12 @@
 
 
 int udp_socket;
-
+// parse args
+int screenId = -1;
+int width    = -1;
+int height   = -1;
+int xOffset  = 0;
+int yOffset  = 0;
 
 void init_device(int fd)
 {
@@ -93,9 +101,83 @@ void quit(int signal) {
 	close(udp_socket);
 }
 
+gfx_host_monitor* getMonitors() {
+	unsigned size = sizeof(gfx_host_monitor);
+	Display *display = XOpenDisplay(0);
+	Window root = RootWindow(display, 0);
 
-int main(void)
+	XRRScreenResources* screenResources = XRRGetScreenResources(display, root);
+	RROutput primary = XRRGetOutputPrimary(display, root);
+
+	int screenCount = 0;
+	gfx_host_monitor* monitors = malloc(size);
+	for (int i = 0; i < screenResources->ncrtc; i++) {
+		XRRCrtcInfo* crtcInfo = XRRGetCrtcInfo(display, screenResources, screenResources->crtcs[i]);
+
+		for (int j = 0; j < crtcInfo->noutput; j++) {
+			XRROutputInfo* outputInfo = XRRGetOutputInfo(display, screenResources, crtcInfo->outputs[j]);
+
+			if (outputInfo->connection != RR_Connected) {
+				XRRFreeOutputInfo(outputInfo);
+				continue;
+			}
+
+			size += sizeof(gfx_host_monitor);
+			gfx_host_monitor* rallac = realloc(monitors, size);
+			if (rallac) {
+				monitors = rallac;
+				if (screenCount > 0) {
+					monitors[i].x = crtcInfo->x + monitors[i - 1].x;
+					monitors[i].y = crtcInfo->y + monitors[i - 1].x;
+				} else {
+					monitors[i].x = crtcInfo->x;
+					monitors[i].y = crtcInfo->y;
+				}
+				monitors[i].width = crtcInfo->width;
+				monitors[i].height = crtcInfo->height;
+				monitors[i].mm_width = outputInfo->mm_width;
+				monitors[i].mm_height = outputInfo->mm_height;
+			} else {
+				// 
+			}
+
+			XRRFreeOutputInfo(outputInfo);
+			screenCount++;
+		}
+		XRRFreeCrtcInfo(crtcInfo);
+	}
+
+	XRRFreeScreenResources(screenResources);
+	for (unsigned i = 0; i < screenCount; i++) {
+		printf("Monitor %d: w:%d h:%d x:%d y:%d\n", i, monitors[i].width, monitors[i].height, monitors[i].x, monitors[i].y);
+	}
+
+	return monitors;
+}
+
+int main(int argc, char *argv[])
 {
+	Display *display = XOpenDisplay(NULL);
+ 	Window root = RootWindow(display, 0);
+ 	int totalWidth = width = XDisplayWidth(display, 0);
+ 	int totalHeight = height = XDisplayHeight(display, 0);
+
+  	printf("totalWidth %d\n", totalWidth);
+
+	int opt;
+	while ((opt = getopt(argc, argv, "s:w:h:x:y:")) != -1) {
+		switch (opt) {
+		case 's': screenId = atoi(optarg); break;
+		case 'w': width = atoi(optarg); break;
+		case 'h': height = atoi(optarg); break;
+		case 'x': xOffset = atoi(optarg); break;
+		case 'y': yOffset = atoi(optarg); break;
+		default:
+			fprintf(stderr, "Usage: %s [-s=SCREEN_NO -w=WIDTH -h=HEIGHT -x=X_OFFSET -y=Y-OFFSET]\n", argv[0]);
+			exit(EXIT_FAILURE);
+		}
+	}
+
 	int device;
 	struct event_packet ev_pkt;
 
@@ -111,6 +193,18 @@ int main(void)
 	signal(SIGINT, quit);
 	signal(SIGTERM, quit);
 
+	gfx_host_monitor* monitors = getMonitors();
+
+	if (screenId != -1) {
+		if (width == -1)
+			width = monitors[screenId].width;
+		if (height == -1)
+			height = monitors[screenId].height;
+		xOffset = monitors[screenId].x + xOffset;
+		yOffset = monitors[screenId].y + yOffset;
+	}
+
+	//print_screen_information();
 	while (recv(udp_socket, &ev_pkt, sizeof(ev_pkt), 0) >= 9) {		// every packet has at least 9 bytes
 		printf("."); fflush(0);
 
@@ -130,9 +224,16 @@ int main(void)
 		ev_pkt.pressure = ntohs(ev_pkt.pressure);
 		printf("x: %hi, y: %hi, pressure: %hi\n", ev_pkt.x, ev_pkt.y, ev_pkt.pressure);
 
+		ev_pkt.x = ev_pkt.x * (float) totalWidth / SHRT_MAX;
+		ev_pkt.x = ev_pkt.x * (float) width / totalWidth;
+		ev_pkt.x = (short) ((float) SHRT_MAX / totalWidth * (xOffset + ev_pkt.x));
+		ev_pkt.y = ev_pkt.y * (float) totalHeight / SHRT_MAX;
+		ev_pkt.y = ev_pkt.y * (float) height / totalHeight;
+		ev_pkt.y = (short) ((float) SHRT_MAX / totalHeight * (yOffset + ev_pkt.y));
 		send_event(device, EV_ABS, ABS_X, ev_pkt.x);
 		send_event(device, EV_ABS, ABS_Y, ev_pkt.y);
-		send_event(device, EV_ABS, ABS_PRESSURE, ev_pkt.pressure);
+
+		//send_event(device, EV_ABS, ABS_PRESSURE, ev_pkt.pressure);
 
 		switch (ev_pkt.type) {
 			case EVENT_TYPE_MOTION:

driver-uinput/protocol.h

@@ -10,6 +10,16 @@
 #define EVENT_TYPE_MOTION 0
 #define EVENT_TYPE_BUTTON 1
 
+typedef struct  
+{
+	int x;
+	int y;
+	unsigned width;
+	unsigned height;
+	unsigned long mm_height;
+	unsigned long mm_width;
+} gfx_host_monitor;
+
 struct event_packet
 {
 	char signature[9];