Migrated image.go, and migrated draw.go as-is. It needs some refactoring.

1 files changed, 57 insertions, 0 deletions

diff --git a/image.go b/image.go
new file mode 100644
index 0000000..d36a401
--- /dev/null
+++ b/image.go
@@ -0,0 +1,57 @@
+// 21 august 2018
+
+package ui
+
+import (
+	"image"
+)
+
+// #include "pkgui.h"
+import "C"
+
+// Image stores an image for display on screen.
+// 
+// Images are built from one or more representations, each with the
+// same aspect ratio but a different pixel size. Package ui
+// automatically selects the most appropriate representation for
+// drawing the image when it comes time to draw the image; what
+// this means depends on the pixel density of the target context.
+// Therefore, one can use Image to draw higher-detailed images on
+// higher-density displays. The typical use cases are either:
+// 
+// 	- have just a single representation, at which point all screens
+// 	  use the same image, and thus uiImage acts like a simple
+// 	  bitmap image, or
+// 	- have two images, one at normal resolution and one at 2x
+// 	  resolution; this matches the current expectations of some
+// 	  desktop systems at the time of writing (mid-2018)
+//
+// Image allocates OS resources; you must explicitly free an Image
+// when you are finished with it.
+type Image struct {
+	i	*C.uiImage
+}
+
+// NewImage creates a new Image with the given width and
+// height. This width and height should be the size in points of the
+// image in the device-independent case; typically this is the 1x size.
+func NewImage(width, height float64) *Image {
+	return &Image{
+		i:	C.uiNewImage(C.double(width), C.double(height)),
+	}
+}
+
+// Free frees the Image.
+func (i *Image) Free() {
+	C.uiFreeImage(i.i)
+}
+
+// Append adds the given image as a representation of the Image.
+func (i *Image) Append(img *image.NRGBA) {
+	cpix := C.CBytes(img.Pix)
+	defer C.free(cpix)
+	C.uiImageAppend(i.i, cpix,
+		C.int(img.Rect.Dx()),
+		C.int(img.Rect.Dy()),
+		C.int(img.Stride))
+}