FreeRDP/libfreerdp/gdi/clipping.c
2022-12-12 14:24:55 +01:00

165 lines
3.4 KiB
C

/**
* 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
*/
HGDI_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)
{
gdi_SetClipRgn(hdc, 0, 0, 0, 0);
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;
GDI_RECT clip;
GDI_RECT coords;
HGDI_BITMAP hBmp;
int dx = 0;
int dy = 0;
BOOL draw = TRUE;
if (hdc == NULL)
return FALSE;
hBmp = (HGDI_BITMAP)hdc->selectedObject;
if (hBmp != NULL)
{
if (hdc->clip->null)
{
gdi_CRgnToRect(0, 0, hBmp->width, hBmp->height, &clip);
}
else
{
gdi_RgnToRect(hdc->clip, &clip);
gdi_CRgnToRect(0, 0, hBmp->width, hBmp->height, &bmp);
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
{
gdi_RgnToRect(hdc->clip, &clip);
}
gdi_CRgnToRect(*x, *y, *w, *h, &coords);
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 != NULL)
*srcx += dx;
if (srcy != NULL)
*srcy += dy;
gdi_RectToCRgn(&coords, x, y, w, h);
return draw;
}