Feat Mac OS Multi-Screen Support of captureScreen()

.gitignore

@@ -1,4 +1,5 @@
 build/
 node_modules/
 prebuilds/
-/.idea
+/.idea
+/.vscode

src/robotjs.cc

@@ -712,8 +712,8 @@ NAN_METHOD(getPixelColor)
 	MMBitmapRef bitmap;
 	MMRGBHex color;
 
-	size_t x = Nan::To<int32_t>(info[0]).FromJust();
-	size_t y = Nan::To<int32_t>(info[1]).FromJust();
+	int32_t x = Nan::To<int32_t>(info[0]).FromJust();
+	int32_t y = Nan::To<int32_t>(info[1]).FromJust();
 
 	if (!pointVisibleOnMainDisplay(MMPointMake(x, y)))
 	{
@@ -797,8 +797,8 @@ NAN_METHOD(setXDisplayName)
 
 NAN_METHOD(captureScreen)
 {
-	size_t x;
-	size_t y;
+	int32_t x;
+	int32_t y;
 	size_t w;
 	size_t h;
 

src/screen.c

@@ -8,6 +8,42 @@
 	#include "xdisplay.h"
 #endif
 
+#if defined(IS_MACOSX)
+uint32_t getIDOfDisplayWithRect(MMRect rect)
+{
+	CGError cgErr;
+	CGDisplayCount displayCount;
+	CGDisplayCount maxDisplays = 1;
+	CGDirectDisplayID onlineDisplays[1];
+	CGRect cgRect = CGRectMake(rect.origin.x,
+		rect.origin.y,
+		rect.size.width,
+		rect.size.height);
+
+	// If CGGetOnlineDisplayList() is not called, CGGetDisplaysWithRect() fails
+	CGGetOnlineDisplayList(maxDisplays, onlineDisplays, &displayCount);
+	cgErr = CGGetDisplaysWithRect(cgRect, maxDisplays, onlineDisplays, &displayCount);
+
+	if (cgErr != kCGErrorSuccess)
+	{
+		fprintf(stderr, "CGGetDisplaysWithRect: error %d.\n", cgErr);
+		exit(1);
+	}
+	if (displayCount == 0)
+	{
+		fprintf(stderr, 
+			"No display with rect with origin (%d, %d), width %d and height %d.\n", 
+			(int) cgRect.origin.x,
+			(int) cgRect.origin.y,
+			(int) cgRect.size.width,
+			(int) cgRect.size.height);
+		exit(1);
+	}
+
+	return onlineDisplays[0];
+};
+#endif
+
 MMSignedSize getMainDisplaySize(void)
 {
 #if defined(IS_MACOSX)

src/screen.h

@@ -15,6 +15,10 @@ extern "C"
 {
 #endif
 
+#if defined(IS_MACOSX)
+	uint32_t getIDOfDisplayWithRect(MMRect rect);
+#endif
+
 /* Returns the size of the main display. */
 MMSignedSize getMainDisplaySize(void);
 

src/screengrab.c

@@ -4,6 +4,7 @@
 #include <stdlib.h> /* malloc() */
 
 #if defined(IS_MACOSX)
+	#include "screen.h"
 	#include <OpenGL/OpenGL.h>
 	#include <OpenGL/gl.h>
 	#include <ApplicationServices/ApplicationServices.h>
@@ -23,11 +24,12 @@ MMBitmapRef copyMMBitmapFromDisplayInRect(MMRect rect)
 	uint8_t *buffer = NULL;
 	size_t bufferSize = 0;
 
-	CGDirectDisplayID displayID = CGMainDisplayID();
+	CGDirectDisplayID displayID = getIDOfDisplayWithRect(rect);
+	CGRect bounds = CGDisplayBounds(displayID);
 
 	CGImageRef image = CGDisplayCreateImageForRect(displayID,
-		CGRectMake(rect.origin.x,
-			rect.origin.y,
+		CGRectMake(rect.origin.x - (int32_t) bounds.origin.x,
+			rect.origin.y - (int32_t) bounds.origin.y,
 			rect.size.width,
 			rect.size.height));
 

src/types.h

@@ -39,7 +39,7 @@ struct _MMSignedSize {
 typedef struct _MMSignedSize MMSignedSize;
 
 struct _MMRect {
-	MMPoint origin;
+	MMSignedPoint origin;
 	MMSize size;
 };
 
@@ -76,10 +76,10 @@ H_INLINE MMSignedSize MMSignedSizeMake(int32_t width, int32_t height)
 	return size;
 }
 
-H_INLINE MMRect MMRectMake(size_t x, size_t y, size_t width, size_t height)
+H_INLINE MMRect MMRectMake(int32_t x, int32_t y, size_t width, size_t height)
 {
 	MMRect rect;
-	rect.origin = MMPointMake(x, y);
+	rect.origin = MMSignedPointMake(x, y);
 	rect.size = MMSizeMake(width, height);
 	return rect;
 }