final fixes on resolution and fix build issue on mac and linux

Overlord-Client/cmd/agent/capture/capture.go

@@ -35,6 +35,8 @@ func Loop(ctx context.Context, env *rt.Env) {
 		done := make(chan struct{})
 		goSafe("capture initial frame", env.Cancel, func() {
 			defer close(done)
+			restore := BypassResolutionCap()
+			defer restore()
 			var err error
 			if goruntime.GOOS == "windows" && activeDisplays() > 1 {
 				err = captureAllDisplaysAndSend(ctx, env)
@@ -197,12 +199,53 @@ func captureAllDisplaysAndSend(ctx context.Context, env *rt.Env) error {
 		}
 	}
 
-	canvas := image.NewRGBA(image.Rect(0, 0, maxX-minX, maxY-minY))
-	for _, part := range parts {
-		offX := part.bounds.Min.X - minX
-		offY := part.bounds.Min.Y - minY
-		dst := image.Rect(offX, offY, offX+part.img.Rect.Dx(), offY+part.img.Rect.Dy())
-		draw.Draw(canvas, dst, part.img, part.img.Rect.Min, draw.Src)
+	// Compute per-monitor scale factors to handle resolution-cap or DPI
+	// mismatches between displayBounds (virtual coords) and captured pixels.
+	type scaledPart struct {
+		img    *image.RGBA
+		scaleX float64
+		scaleY float64
+		offX   int
+		offY   int
+	}
+	scaled := make([]scaledPart, len(parts))
+	for i, part := range parts {
+		sx, sy := 1.0, 1.0
+		bw := part.bounds.Dx()
+		bh := part.bounds.Dy()
+		iw := part.img.Rect.Dx()
+		ih := part.img.Rect.Dy()
+		if bw > 0 && iw > 0 {
+			sx = float64(iw) / float64(bw)
+		}
+		if bh > 0 && ih > 0 {
+			sy = float64(ih) / float64(bh)
+		}
+		scaled[i] = scaledPart{
+			img:    part.img,
+			scaleX: sx,
+			scaleY: sy,
+			offX:   int(float64(part.bounds.Min.X-minX) * sx),
+			offY:   int(float64(part.bounds.Min.Y-minY) * sy),
+		}
+	}
+
+	// Canvas sized from scaled image placements.
+	cW, cH := 0, 0
+	for _, sp := range scaled {
+		rx := sp.offX + sp.img.Rect.Dx()
+		ry := sp.offY + sp.img.Rect.Dy()
+		if rx > cW {
+			cW = rx
+		}
+		if ry > cH {
+			cH = ry
+		}
+	}
+	canvas := image.NewRGBA(image.Rect(0, 0, cW, cH))
+	for _, sp := range scaled {
+		dst := image.Rect(sp.offX, sp.offY, sp.offX+sp.img.Rect.Dx(), sp.offY+sp.img.Rect.Dy())
+		draw.Draw(canvas, dst, sp.img, sp.img.Rect.Min, draw.Src)
 	}
 
 	quality := jpegQuality()

Overlord-Client/cmd/agent/capture/cursor_windows.go

@@ -196,6 +196,10 @@ func drawCursor(img *image.RGBA, cursorX, cursorY int32, bounds image.Rectangle)
 }
 
 func DrawCursorOnDC(hdc uintptr, captureBounds image.Rectangle) bool {
+	return DrawCursorOnDCScaled(hdc, captureBounds, 1.0, 1.0)
+}
+
+func DrawCursorOnDCScaled(hdc uintptr, captureBounds image.Rectangle, scaleX, scaleY float64) bool {
 	if !cursorCaptureEnabled.Load() || hdc == 0 {
 		return false
 	}
@@ -217,8 +221,9 @@ func DrawCursorOnDC(hdc uintptr, captureBounds image.Rectangle) bool {
 		defer deleteObject(icon.hbmColor)
 	}
 
-	x := int32(ci.ptScreenPos.x) - int32(captureBounds.Min.X) - int32(icon.xHotspot)
-	y := int32(ci.ptScreenPos.y) - int32(captureBounds.Min.Y) - int32(icon.yHotspot)
+	// Map from screen space into the (possibly scaled) DC space.
+	x := int32(float64(ci.ptScreenPos.x-int32(captureBounds.Min.X))*scaleX) - int32(icon.xHotspot)
+	y := int32(float64(ci.ptScreenPos.y-int32(captureBounds.Min.Y))*scaleY) - int32(icon.yHotspot)
 	ret, _, _ = procDrawIconEx.Call(
 		hdc,
 		uintptr(x),

Overlord-Client/cmd/agent/capture/resolution_default.go

@@ -0,0 +1,13 @@
+//go:build !windows
+
+package capture
+
+func SetMaxResolution(maxH int) {}
+
+func BypassResolutionCap() (restore func()) {
+	return func() {}
+}
+
+func EffectiveScaleForInput() float64 {
+	return 1.0
+}

Overlord-Client/cmd/agent/capture/win_bitblt.go

@@ -227,7 +227,7 @@ func captureDisplayBitBlt(display int) (*image.RGBA, error) {
 		dstH = srcH
 	}
 
-	useStretch := dstW > 0 && dstH > 0 && (dstW < srcW || dstH < srcH) && !cursorCaptureEnabled.Load()
+	useStretch := dstW > 0 && dstH > 0 && (dstW < srcW || dstH < srcH)
 	capW := srcW
 	capH := srcH
 	if useStretch {
@@ -290,7 +290,11 @@ func captureDisplayBitBlt(display int) (*image.RGBA, error) {
 		}
 		bitDur := time.Since(bitStart)
 		cursorDrawn := false
-		if !useStretch {
+		if useStretch {
+			sx := float64(capW) / float64(srcW)
+			sy := float64(capH) / float64(srcH)
+			cursorDrawn = DrawCursorOnDCScaled(hdcMem, bounds, sx, sy)
+		} else {
 			cursorDrawn = DrawCursorOnDC(hdcMem, bounds)
 		}
 
@@ -544,6 +548,11 @@ func SetMaxResolution(maxH int) {
 	log.Printf("capture: max resolution set to %d", maxH)
 }
 
+func BypassResolutionCap() (restore func()) {
+	old := maxResHeight.Swap(-1)
+	return func() { maxResHeight.Store(old) }
+}
+
 func EffectiveScaleForInput() float64 {
 	bits := lastCapScale.Load()
 	if bits == 0 {