SDL  2.0
SDL_windowsshape.c
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1 /*
2  Simple DirectMedia Layer
3  Copyright (C) 1997-2018 Sam Lantinga <slouken@libsdl.org>
4 
5  This software is provided 'as-is', without any express or implied
6  warranty. In no event will the authors be held liable for any damages
7  arising from the use of this software.
8 
9  Permission is granted to anyone to use this software for any purpose,
10  including commercial applications, and to alter it and redistribute it
11  freely, subject to the following restrictions:
12 
13  1. The origin of this software must not be misrepresented; you must not
14  claim that you wrote the original software. If you use this software
15  in a product, an acknowledgment in the product documentation would be
16  appreciated but is not required.
17  2. Altered source versions must be plainly marked as such, and must not be
18  misrepresented as being the original software.
19  3. This notice may not be removed or altered from any source distribution.
20 */
21 #include "../../SDL_internal.h"
22 
23 #if SDL_VIDEO_DRIVER_WINDOWS
24 
25 #include "SDL_assert.h"
26 #include "SDL_windowsshape.h"
27 #include "SDL_windowsvideo.h"
28 
29 SDL_WindowShaper*
30 Win32_CreateShaper(SDL_Window * window) {
31  int resized_properly;
32  SDL_WindowShaper* result = (SDL_WindowShaper *)SDL_malloc(sizeof(SDL_WindowShaper));
33  result->window = window;
34  result->mode.mode = ShapeModeDefault;
35  result->mode.parameters.binarizationCutoff = 1;
36  result->userx = result->usery = 0;
37  result->driverdata = (SDL_ShapeData*)SDL_malloc(sizeof(SDL_ShapeData));
38  ((SDL_ShapeData*)result->driverdata)->mask_tree = NULL;
39  /* Put some driver-data here. */
40  window->shaper = result;
41  resized_properly = Win32_ResizeWindowShape(window);
42  if (resized_properly != 0)
43  return NULL;
44 
45  return result;
46 }
47 
48 static void
49 CombineRectRegions(SDL_ShapeTree* node,void* closure) {
50  HRGN mask_region = *((HRGN*)closure),temp_region = NULL;
51  if(node->kind == OpaqueShape) {
52  /* Win32 API regions exclude their outline, so we widen the region by one pixel in each direction to include the real outline. */
53  temp_region = CreateRectRgn(node->data.shape.x,node->data.shape.y,node->data.shape.x + node->data.shape.w + 1,node->data.shape.y + node->data.shape.h + 1);
54  if(mask_region != NULL) {
55  CombineRgn(mask_region,mask_region,temp_region,RGN_OR);
56  DeleteObject(temp_region);
57  }
58  else
59  *((HRGN*)closure) = temp_region;
60  }
61 }
62 
63 int
64 Win32_SetWindowShape(SDL_WindowShaper *shaper,SDL_Surface *shape,SDL_WindowShapeMode *shape_mode) {
65  SDL_ShapeData *data;
66  HRGN mask_region = NULL;
67 
68  if( (shaper == NULL) ||
69  (shape == NULL) ||
70  ((shape->format->Amask == 0) && (shape_mode->mode != ShapeModeColorKey)) ||
71  (shape->w != shaper->window->w) ||
72  (shape->h != shaper->window->h) ) {
73  return SDL_INVALID_SHAPE_ARGUMENT;
74  }
75 
76  data = (SDL_ShapeData*)shaper->driverdata;
77  if(data->mask_tree != NULL)
78  SDL_FreeShapeTree(&data->mask_tree);
79  data->mask_tree = SDL_CalculateShapeTree(*shape_mode,shape);
80 
81  SDL_TraverseShapeTree(data->mask_tree,&CombineRectRegions,&mask_region);
82  SDL_assert(mask_region != NULL);
83 
84  SetWindowRgn(((SDL_WindowData *)(shaper->window->driverdata))->hwnd, mask_region, TRUE);
85 
86  return 0;
87 }
88 
89 int
90 Win32_ResizeWindowShape(SDL_Window *window) {
91  SDL_ShapeData* data;
92 
93  if (window == NULL)
94  return -1;
95  data = (SDL_ShapeData *)window->shaper->driverdata;
96  if (data == NULL)
97  return -1;
98 
99  if(data->mask_tree != NULL)
100  SDL_FreeShapeTree(&data->mask_tree);
101  if(window->shaper->hasshape == SDL_TRUE) {
102  window->shaper->userx = window->x;
103  window->shaper->usery = window->y;
104  SDL_SetWindowPosition(window,-1000,-1000);
105  }
106 
107  return 0;
108 }
109 
110 #endif /* SDL_VIDEO_DRIVER_WINDOWS */