Add Image.beginPixelDataAccess() and endPixelDataAccess() for fast image manipulation

1 files changed, 12 insertions, 4 deletions

diff --git a/src/nigui/private/gtk3/platform_impl.nim b/src/nigui/private/gtk3/platform_impl.nim
index 0d0c420..09db57c 100755
--- a/src/nigui/private/gtk3/platform_impl.nim
+++ b/src/nigui/private/gtk3/platform_impl.nim
@@ -468,10 +468,10 @@ method setPixel(canvas: Canvas, x, y: int, color: Color) =
       raiseError("Pixel is out of range.")
     cairo_surface_flush(canvasImpl.fSurface)
     let i = y * canvasImpl.fStride + x * 4
-    canvasImpl.fData[i + 0] = color.blue.chr
-    canvasImpl.fData[i + 1] = color.green.chr
-    canvasImpl.fData[i + 2] = color.red.chr
-    canvasImpl.fData[i + 3] = 255.chr
+    canvasImpl.fData[i + 0] = color.blue
+    canvasImpl.fData[i + 1] = color.green
+    canvasImpl.fData[i + 2] = color.red
+    canvasImpl.fData[i + 3] = 255
     cairo_surface_mark_dirty(canvasImpl.fSurface)
 
 method `fontFamily=`(canvas: CanvasImpl, fontFamily: string) =
@@ -555,6 +555,14 @@ method saveToJpegFile(image: Image, filePath: string, quality = 80) =
   if not gdk_pixbuf_save(pixbuf, filePath, "jpeg", error.addr, "quality", $quality, nil):
     pRaiseGError(error)
 
+method beginPixelDataAccess(image: Image): ptr UncheckedArray[byte] =
+  let canvas = cast[CanvasImpl](image.canvas)
+  result = canvas.fData
+
+method endPixelDataAccess(image: Image) =
+  let canvas = cast[CanvasImpl](image.canvas)
+  cairo_surface_mark_dirty(canvas.fSurface)
+
 
 # ----------------------------------------------------------------------------------------
 #                                        Window