Files
galaxy-game/client/world/drawer_clear_state_test.go
T
2026-03-08 23:30:11 +02:00

41 lines
1.1 KiB
Go

package world
import (
"image/color"
"testing"
"github.com/fogleman/gg"
"github.com/stretchr/testify/require"
)
func TestGGDrawer_ClearRectTo_DoesNotAffectStrokeState(t *testing.T) {
t.Parallel()
dc := gg.NewContext(40, 20)
d := &GGDrawer{DC: dc}
// Fill background to white.
d.ClearAllTo(color.RGBA{R: 255, G: 255, B: 255, A: 255})
// Configure stroke to red and draw first line.
d.SetStrokeColor(color.RGBA{R: 255, A: 255})
d.SetLineWidth(2)
d.AddLine(2, 5, 38, 5)
d.Stroke()
// Clear a rect in the middle with gray (must not affect stroke state).
d.ClearRectTo(10, 0, 20, 20, color.RGBA{R: 200, G: 200, B: 200, A: 255})
// Draw second line WITHOUT reapplying stroke style; it must still be red.
d.AddLine(2, 15, 38, 15)
d.Stroke()
img := dc.Image()
// Sample a pixel from the second line (y ~15). We expect red channel dominates.
r, g, b, a := img.At(20, 15).RGBA()
require.Greater(t, a, uint32(0), "pixel must not be fully transparent")
require.Greater(t, r, g, "expected red-ish pixel after ClearRectTo")
require.Greater(t, r, b, "expected red-ish pixel after ClearRectTo")
}