colorpick/screenshot: make color-format aware

core/internal/screenshot/encode.go

@@ -13,8 +13,15 @@ import (
 )
 
 func BufferToImage(buf *ShmBuffer) *image.RGBA {
+	return BufferToImageWithFormat(buf, uint32(FormatARGB8888))
+}
+
+func BufferToImageWithFormat(buf *ShmBuffer, format uint32) *image.RGBA {
 	img := image.NewRGBA(image.Rect(0, 0, buf.Width, buf.Height))
 	data := buf.Data()
+
+	swapRB := format == uint32(FormatARGB8888) || format == uint32(FormatXRGB8888) || format == 0
+
 	for y := 0; y < buf.Height; y++ {
 		srcOff := y * buf.Stride
 		dstOff := y * img.Stride
@@ -24,10 +31,16 @@ func BufferToImage(buf *ShmBuffer) *image.RGBA {
 			if si+3 >= len(data) || di+3 >= len(img.Pix) {
 				continue
 			}
-			img.Pix[di+0] = data[si+2] // R
-			img.Pix[di+1] = data[si+1] // G
-			img.Pix[di+2] = data[si+0] // B
-			img.Pix[di+3] = 255        // A
+			if swapRB {
+				img.Pix[di+0] = data[si+2]
+				img.Pix[di+1] = data[si+1]
+				img.Pix[di+2] = data[si+0]
+			} else {
+				img.Pix[di+0] = data[si+0]
+				img.Pix[di+1] = data[si+1]
+				img.Pix[di+2] = data[si+2]
+			}
+			img.Pix[di+3] = 255
 		}
 	}
 	return img
@@ -162,13 +175,17 @@ func expandHome(path string) string {
 }
 
 func WriteToFile(buf *ShmBuffer, path string, format Format, quality int) error {
+	return WriteToFileWithFormat(buf, path, format, quality, uint32(FormatARGB8888))
+}
+
+func WriteToFileWithFormat(buf *ShmBuffer, path string, format Format, quality int, pixelFormat uint32) error {
 	f, err := os.Create(path)
 	if err != nil {
 		return err
 	}
 	defer f.Close()
 
-	img := BufferToImage(buf)
+	img := BufferToImageWithFormat(buf, pixelFormat)
 	switch format {
 	case FormatJPEG:
 		return EncodeJPEG(f, img, quality)

core/internal/screenshot/region.go

@@ -160,14 +160,17 @@ func (r *RegionSelector) Run() (*CaptureResult, bool, error) {
 	}
 
 	yInverted := false
+	var format uint32
 	if r.selection.surface != nil {
 		yInverted = r.selection.surface.yInverted
+		format = r.selection.surface.screenFormat
 	}
 
 	return &CaptureResult{
 		Buffer:    r.capturedBuffer,
-		Region:    r.result, // Global coords for saving last region
+		Region:    r.result,
 		YInverted: yInverted,
+		Format:    format,
 	}, false, nil
 }
 

core/internal/screenshot/region_input.go

@@ -98,9 +98,10 @@ func (r *RegionSelector) setupPointerHandlers() {
 		case 0x110: // BTN_LEFT
 			switch e.State {
 			case 1: // pressed
+				r.preSelect = Region{}
 				r.selection.hasSelection = true
 				r.selection.dragging = true
-				r.selection.surface = r.activeSurface // Lock to this surface
+				r.selection.surface = r.activeSurface
 				r.selection.anchorX = r.pointerX
 				r.selection.anchorY = r.pointerY
 				r.selection.currentX = r.pointerX

core/internal/screenshot/screenshot.go

@@ -25,6 +25,7 @@ type CaptureResult struct {
 	Buffer    *ShmBuffer
 	Region    Region
 	YInverted bool
+	Format    uint32
 }
 
 type Screenshoter struct {
@@ -206,6 +207,7 @@ func (s *Screenshoter) captureAllScreens() (*CaptureResult, error) {
 
 	composite.Clear()
 
+	var format uint32
 	for _, output := range outputs {
 		result, err := s.captureWholeOutput(output)
 		if err != nil {
@@ -213,6 +215,9 @@ func (s *Screenshoter) captureAllScreens() (*CaptureResult, error) {
 			continue
 		}
 
+		if format == 0 {
+			format = result.Format
+		}
 		s.blitBuffer(composite, result.Buffer, int(output.x-minX), int(output.y-minY), result.YInverted)
 		result.Buffer.Close()
 	}
@@ -220,6 +225,7 @@ func (s *Screenshoter) captureAllScreens() (*CaptureResult, error) {
 	return &CaptureResult{
 		Buffer: composite,
 		Region: Region{X: minX, Y: minY, Width: totalW, Height: totalH},
+		Format: format,
 	}, nil
 }
 
@@ -379,6 +385,7 @@ func (s *Screenshoter) processFrame(frame *wlr_screencopy.ZwlrScreencopyFrameV1,
 		Buffer:    buf,
 		Region:    region,
 		YInverted: yInverted,
+		Format:    uint32(format),
 	}, nil
 }