The new field ImageOp.Rect is initialized to cover the entire source
image, but can be modified to draw only a section of it.
Signed-off-by: Elias Naur <mail@eliasnaur.com>
The ability to invoke other operation lists belongs in the new CallOp.
While we're here, make MacroOp.Add use a pointer receiver to match the
other methods.
Signed-off-by: Elias Naur <mail@eliasnaur.com>
We'd like to improve the API of Flex, Stack and similar layouts
that use MacroOps internall. Unfortunately, the
func (m MacroOp) Add(o *Ops)
method causes the MacroOp to be allocated on the heap, ruining the
nice garbage-free property of layouts.
Fortunately, layouts don't need the feature that caused the heap
allocation: invoking operation lists different than the current.
CallOp separates the invoke-different-list semantic from MacroOp,
in preparation for removing the feature from MacroOp.
Signed-off-by: Elias Naur <mail@eliasnaur.com>
The gioui.org/commit/74407a50d598bfd27e8f8e48b6832cc5df04de77
added a NewImageOp constructor that always copies the supplied
image. It does that for two reasons:
First, the image.Image reference is used in the image=>texture
map of cached textures. Without a copy, we wouldn't detect a
modified image even if a new ImageOp was created.
Second, we don't want the program to touch the image while the GPU
is uploading it.
The second reason was removed in a previous change that blocks
FrameEvent.Frame until we're done with the operations, including
uploading images to the GPU.
The first reason is easily fixed by using a unique per ImageOp,
as pointed out by Alessandro Arzilli.
This change switches to using the unique key. Alessandro's patch
avoids the copy when possible.
Signed-off-by: Elias Naur <mail@eliasnaur.com>
Elias Naur