image_test.go raw

   1  // SPDX-License-Identifier: Unlicense OR MIT
   2  
   3  package widget
   4  
   5  import (
   6  	"image"
   7  	"testing"
   8  
   9  	"github.com/p9c/p9/pkg/gel/gio/layout"
  10  	"github.com/p9c/p9/pkg/gel/gio/op"
  11  	"github.com/p9c/p9/pkg/gel/gio/op/paint"
  12  )
  13  
  14  func TestImageScale(t *testing.T) {
  15  	var ops op.Ops
  16  	gtx := layout.Context{
  17  		Ops: &ops,
  18  		Constraints: layout.Constraints{
  19  			Max: image.Pt(50, 50),
  20  		},
  21  	}
  22  	imgSize := image.Pt(10, 10)
  23  	img := image.NewNRGBA(image.Rectangle{Max: imgSize})
  24  	imgOp := paint.NewImageOp(img)
  25  
  26  	// Ensure the default scales correctly.
  27  	dims := Image{Src: imgOp}.Layout(gtx)
  28  	expectedSize := imgSize
  29  	expectedSize.X = int(float32(expectedSize.X) * defaultScale)
  30  	expectedSize.Y = int(float32(expectedSize.Y) * defaultScale)
  31  	if dims.Size != expectedSize {
  32  		t.Fatalf("non-scaled image is wrong size, expected %v, got %v", expectedSize, dims.Size)
  33  	}
  34  
  35  	// Ensure scaling the image via the Scale field works.
  36  	currentScale := float32(0.5)
  37  	dims = Image{Src: imgOp, Scale: float32(currentScale)}.Layout(gtx)
  38  	expectedSize = imgSize
  39  	expectedSize.X = int(float32(expectedSize.X) * currentScale)
  40  	expectedSize.Y = int(float32(expectedSize.Y) * currentScale)
  41  	if dims.Size != expectedSize {
  42  		t.Fatalf(".5 scale image is wrong size, expected %v, got %v", expectedSize, dims.Size)
  43  	}
  44  
  45  	// Ensure the image responds to changes in DPI.
  46  	currentScale = float32(1)
  47  	gtx.Metric.PxPerDp = 2
  48  	dims = Image{Src: imgOp, Scale: float32(currentScale)}.Layout(gtx)
  49  	expectedSize = imgSize
  50  	expectedSize.X = int(float32(expectedSize.X) * currentScale * gtx.Metric.PxPerDp)
  51  	expectedSize.Y = int(float32(expectedSize.Y) * currentScale * gtx.Metric.PxPerDp)
  52  	if dims.Size != expectedSize {
  53  		t.Fatalf("HiDPI non-scaled image is wrong size, expected %v, got %v", expectedSize, dims.Size)
  54  	}
  55  
  56  	// Ensure scaling the image responds to changes in DPI.
  57  	currentScale = float32(.5)
  58  	gtx.Metric.PxPerDp = 2
  59  	dims = Image{Src: imgOp, Scale: float32(currentScale)}.Layout(gtx)
  60  	expectedSize = imgSize
  61  	expectedSize.X = int(float32(expectedSize.X) * currentScale * gtx.Metric.PxPerDp)
  62  	expectedSize.Y = int(float32(expectedSize.Y) * currentScale * gtx.Metric.PxPerDp)
  63  	if dims.Size != expectedSize {
  64  		t.Fatalf("HiDPI .5 scale image is wrong size, expected %v, got %v", expectedSize, dims.Size)
  65  	}
  66  }
  67