Milestone 5: deliver embedded RDP sessions and lifecycle hardening

third_party/FreeRDP/libfreerdp/gdi/clipping.c

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+/**
+ * FreeRDP: A Remote Desktop Protocol Implementation
+ * GDI Clipping Functions
+ *
+ * Copyright 2010-2011 Marc-Andre Moreau <marcandre.moreau@gmail.com>
+ * Copyright 2016 Armin Novak <armin.novak@thincast.com>
+ * Copyright 2016 Thincast Technologies GmbH
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <freerdp/config.h>
+
+#include <stdio.h>
+#include <string.h>
+#include <stdlib.h>
+
+#include <freerdp/freerdp.h>
+#include <freerdp/gdi/gdi.h>
+
+#include <freerdp/gdi/region.h>
+
+#include "clipping.h"
+
+BOOL gdi_SetClipRgn(HGDI_DC hdc, INT32 nXLeft, INT32 nYLeft, INT32 nWidth, INT32 nHeight)
+{
+	return gdi_SetRgn(hdc->clip, nXLeft, nYLeft, nWidth, nHeight);
+}
+
+/**
+ * Get the current clipping region.
+ * msdn{dd144866}
+ *
+ * @param hdc device context
+ * @return clipping region
+ */
+
+GDI_RGN* gdi_GetClipRgn(HGDI_DC hdc)
+{
+	return hdc->clip;
+}
+
+/**
+ * Set the current clipping region to null.
+ * @param hdc device context
+ * @return nonzero on success, 0 otherwise
+ */
+
+BOOL gdi_SetNullClipRgn(HGDI_DC hdc)
+{
+	if (!gdi_SetClipRgn(hdc, 0, 0, 0, 0))
+		return FALSE;
+	hdc->clip->null = TRUE;
+	return TRUE;
+}
+
+/**
+ * Clip coordinates according to clipping region
+ * @param hdc device context
+ * @param x x1
+ * @param y y1
+ * @param w width
+ * @param h height
+ * @param srcx source x1
+ * @param srcy source y1
+ * @return nonzero if there is something to draw, 0 otherwise
+ */
+
+BOOL gdi_ClipCoords(HGDI_DC hdc, INT32* x, INT32* y, INT32* w, INT32* h, INT32* srcx, INT32* srcy)
+{
+	GDI_RECT bmp = WINPR_C_ARRAY_INIT;
+	GDI_RECT clip = WINPR_C_ARRAY_INIT;
+	GDI_RECT coords = WINPR_C_ARRAY_INIT;
+	int dx = 0;
+	int dy = 0;
+	BOOL draw = TRUE;
+
+	if (hdc == nullptr)
+		return FALSE;
+
+	HGDI_BITMAP hBmp = (HGDI_BITMAP)hdc->selectedObject;
+
+	if (hBmp != nullptr)
+	{
+		if (hdc->clip->null)
+		{
+			if (!gdi_CRgnToRect(0, 0, hBmp->width, hBmp->height, &clip))
+				return TRUE;
+		}
+		else
+		{
+			if (!gdi_RgnToRect(hdc->clip, &clip))
+				return TRUE;
+			if (!gdi_CRgnToRect(0, 0, hBmp->width, hBmp->height, &bmp))
+				return TRUE;
+
+			if (clip.left < bmp.left)
+				clip.left = bmp.left;
+
+			if (clip.right > bmp.right)
+				clip.right = bmp.right;
+
+			if (clip.top < bmp.top)
+				clip.top = bmp.top;
+
+			if (clip.bottom > bmp.bottom)
+				clip.bottom = bmp.bottom;
+		}
+	}
+	else
+	{
+		if (!gdi_RgnToRect(hdc->clip, &clip))
+			return TRUE;
+	}
+
+	if (!gdi_CRgnToRect(*x, *y, *w, *h, &coords))
+		return TRUE;
+
+	if (coords.right >= clip.left && coords.left <= clip.right && coords.bottom >= clip.top &&
+	    coords.top <= clip.bottom)
+	{
+		/* coordinates overlap with clipping region */
+		if (coords.left < clip.left)
+		{
+			dx = (clip.left - coords.left);
+			coords.left = clip.left;
+		}
+
+		if (coords.right > clip.right)
+			coords.right = clip.right;
+
+		if (coords.top < clip.top)
+		{
+			dy = (clip.top - coords.top);
+			coords.top = clip.top;
+		}
+
+		if (coords.bottom > clip.bottom)
+			coords.bottom = clip.bottom;
+	}
+	else
+	{
+		/* coordinates do not overlap with clipping region */
+		coords.left = 0;
+		coords.right = 0;
+		coords.top = 0;
+		coords.bottom = 0;
+		draw = FALSE;
+	}
+
+	if (srcx != nullptr)
+		*srcx += dx;
+
+	if (srcy != nullptr)
+		*srcy += dy;
+
+	if (!gdi_RectToCRgn(&coords, x, y, w, h))
+		return FALSE;
+	return draw;
+}