QPainter does not like to draw in an empty QImage.
And the rendering code does not like to render it.
So we would get this on the console:
```
QPainter::begin: Paint device returned engine == 0, type: 3
QPainter::save: Painter not active
QPainter::save: Painter not active
QPainter::setRenderHint: Painter must be active to set rendering hints
QPainter::save: Painter not active
QPainter::setClipRegion: Painter not active
QPainter::setPen: Painter not active
QPainter::setBrush: Painter not active
QPainter::restore: Unbalanced save/restore
QPainter::setPen: Painter not active
QPainter::setBrush: Painter not active
QPainter::restore: Unbalanced save/restore
QPainter::save: Painter not active
QPainter::restore: Unbalanced save/restore
QPainter::restore: Unbalanced save/restore
thread 'main' panicked at 'attempt to subtract with overflow', sixtyfps_runtime/rendering_backends/gl/texture.rs:285:42
```
Make the text color a rendering variable, so that it can be passed
through as uniform to the glyph shader and applied to the gray
map of the glyphs. This avoids re-creating the glyph runs when
merely the color changes.
This already "worked" for the glyph cache based text rendering,
but it wasn't used because of the wasm canvas code path. This
patch changes that to render the text into a text using simply black
and then render that texture using our existing glyph shader,
which merely uses the alpha channel anyway.
This reduces also #cfg's.
Currently the Qt backend still redirect everything to the GL backend,
but the goal is to use QPainter and QWindow
This also adds a "default" backend, whose goal is to select the proper
backend at compile time
We do not get move or release event when the cursor is outside of the canvas
as a result, we would have no way of detecting that the mouse has been released
outside and we would be in a inconsistant state.
Fixes#19
We support directly nested layouts, but we did not support indirect
nesting:
GridLayout {
Rectangle {
l2 := GridLayout { ... }
}
}
This patch fixes that by detecting this scenario and merging the layout
info of the element (Rectangle) and the layout inside (l2). This makes
it much easier to create re-usable components that use layouts
themselves and allows placing them in layouts.
When the spacing was zero, the constraints would always be zero due to
accidental multiplication with the accumulated spacing widths/heights.
That was meant to be an addition.
Since Doxygen can't seem to just exclude them via command, they are moved
into a private_api namespace and then excluded via Doxygen config:
* *VTable
* make_dyn_node, ItemTreeNode, etc.
* VersionCheck
- Give all the sixtyfps-* create a 0.0.1 version
- Make sure that the internal dependences are using the exact same version
(so "=0.0.1")
- Add the description/homepage/repository fields in the .toml files
- Set publish=false to crates that are not meant to be published on crates.io
Borrow the rendering and cache individually with different mutability.
We might later, for destruction handling, need to borrow the rendering
cache mutably. That in turn *may* happen even during rendering itself,
as the models are updated lazily during visitor traversal and that may
result in item destruction.
Instead, pass a reference to the root item when mapping the window,
at which point we can downcast to the new Window item. If we have one,
then we'll read its width/height (for initial values) and install
bindings to keep them up-to-date.
