Create pixbuf from data

can-lehmann · Feb 26, 2023 · cd36e37 · cd36e37
1 parent a8c7cbd
commit cd36e37
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Showing 2 changed files with 34 additions and 1 deletion.
diff --git a/owlkettle/gtk.nim b/owlkettle/gtk.nim
@@ -429,6 +429,12 @@ proc gdk_clipboard_set_text*(clipboard: GdkClipboard, text: cstring, length: cin
 proc gdk_pixbuf_new*(colorspace: GdkColorspace,
                      hasAlpha: cbool,
                      bitsPerSample, w, h: cint): GdkPixbuf
+proc gdk_pixbuf_new_from_data*(pixels: pointer,
+                               colorspace: GdkColorspace,
+                               hasAlpha: cbool,
+                               bitsPerSample, w, h, stride: cint,
+                               destroy: proc(pixels, data: pointer) {.cdecl.},
+                               destroyData: pointer): GdkPixbuf
 proc gdk_pixbuf_new_from_file*(path: cstring, error: ptr GError): GdkPixbuf
 proc gdk_pixbuf_new_from_file_at_scale*(path: cstring,
                                         w, h: cint,

diff --git a/owlkettle/widgets.nim b/owlkettle/widgets.nim
@@ -445,7 +445,7 @@ proc newPixbuf(gdk: GdkPixbuf): Pixbuf =
   result.gdk = gdk
 
 proc newPixbuf*(width, height: int,
-                bitsPerSample: int,
+                bitsPerSample: int = 8,
                 hasAlpha: bool = false,
                 colorspace: Colorspace = ColorspaceRgb): Pixbuf =
   result = newPixbuf(gdk_pixbuf_new(
@@ -456,6 +456,33 @@ proc newPixbuf*(width, height: int,
     height.cint
   ))
 
+proc newPixbuf*(width, height: int,
+                data: openArray[uint8],
+                bitsPerSample: int = 8,
+                hasAlpha: bool = false,
+                colorspace: Colorspace = ColorspaceRgb): Pixbuf =
+  let channels = if hasAlpha: 4 else: 3
+  assert width * height * channels * (bitsPerSample div 8) == data.len
+
+  proc destroy(pixels: pointer, data: pointer) {.cdecl.} =
+    dealloc(pixels)
+
+  let buffer = cast[ptr UncheckedArray[uint8]](alloc(data.len))
+  if data.len > 0:
+    copyMem(buffer, data[0].unsafeAddr, data.len)
+
+  result = newPixbuf(gdk_pixbuf_new_from_data(
+    buffer,
+    GdkColorspace(ord(colorspace)),
+    cbool(ord(hasAlpha)),
+    bitsPerSample.cint,
+    width.cint,
+    height.cint,
+    cint(channels * width * (bitsPerSample div 8)),
+    destroy,
+    nil
+  ))
+
 proc loadPixbuf*(path: string): Pixbuf =
   var error = GError(nil)
   let pixbuf = gdk_pixbuf_new_from_file(path.cstring, error.addr)