Files
gio-patched/widget/image.go
T
Elias Naur 852958f4b5 gpu,widget,op/paint,gpu: remove support for ImageOp.Rect
This is effectively a revert of commit gioui.org/commit/69dfd2e3a5541.

ImageOp.Rect is the wrong abstraction; it implies a clipping operation that is
better handled by package clip.

API change. Uses of ImageOp.Rect should apply a clip.Rect before the PaintOp,
or use image.RGBA.SubImage (or similar).

Signed-off-by: Elias Naur <mail@eliasnaur.com>
2020-11-05 13:36:36 +01:00

43 lines
1017 B
Go

// SPDX-License-Identifier: Unlicense OR MIT
package widget
import (
"image"
"gioui.org/f32"
"gioui.org/layout"
"gioui.org/op"
"gioui.org/op/clip"
"gioui.org/op/paint"
"gioui.org/unit"
)
// Image is a widget that displays an image.
type Image struct {
// Src is the image to display.
Src paint.ImageOp
// Scale is the ratio of image pixels to
// dps. If Scale is zero Image falls back to
// a scale that match a standard 72 DPI.
Scale float32
}
func (im Image) Layout(gtx layout.Context) layout.Dimensions {
scale := im.Scale
if scale == 0 {
scale = 160.0 / 72.0
}
size := im.Src.Size()
wf, hf := float32(size.X), float32(size.Y)
w, h := gtx.Px(unit.Dp(wf*scale)), gtx.Px(unit.Dp(hf*scale))
cs := gtx.Constraints
d := cs.Constrain(image.Pt(w, h))
stack := op.Push(gtx.Ops)
clip.Rect(image.Rectangle{Max: d}).Add(gtx.Ops)
im.Src.Add(gtx.Ops)
paint.PaintOp{Rect: f32.Rectangle{Max: f32.Point{X: float32(w), Y: float32(h)}}}.Add(gtx.Ops)
stack.Pop()
return layout.Dimensions{Size: d}
}