1 /*
2   Simple DirectMedia Layer
3   Copyright (C) 1997-2020 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*
Win32_CreateShaper(SDL_Window * window)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->hasshape = SDL_FALSE;
38     result->driverdata = (SDL_ShapeData*)SDL_malloc(sizeof(SDL_ShapeData));
39     ((SDL_ShapeData*)result->driverdata)->mask_tree = NULL;
40     /* Put some driver-data here. */
41     window->shaper = result;
42     resized_properly = Win32_ResizeWindowShape(window);
43     if (resized_properly != 0)
44             return NULL;
45 
46     return result;
47 }
48 
49 static void
CombineRectRegions(SDL_ShapeTree * node,void * closure)50 CombineRectRegions(SDL_ShapeTree* node,void* closure) {
51     HRGN mask_region = *((HRGN*)closure),temp_region = NULL;
52     if(node->kind == OpaqueShape) {
53         /* Win32 API regions exclude their outline, so we widen the region by one pixel in each direction to include the real outline. */
54         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);
55         if(mask_region != NULL) {
56             CombineRgn(mask_region,mask_region,temp_region,RGN_OR);
57             DeleteObject(temp_region);
58         }
59         else
60             *((HRGN*)closure) = temp_region;
61     }
62 }
63 
64 int
Win32_SetWindowShape(SDL_WindowShaper * shaper,SDL_Surface * shape,SDL_WindowShapeMode * shape_mode)65 Win32_SetWindowShape(SDL_WindowShaper *shaper,SDL_Surface *shape,SDL_WindowShapeMode *shape_mode) {
66     SDL_ShapeData *data;
67     HRGN mask_region = NULL;
68 
69     if( (shaper == NULL) ||
70         (shape == NULL) ||
71         ((shape->format->Amask == 0) && (shape_mode->mode != ShapeModeColorKey)) ||
72         (shape->w != shaper->window->w) ||
73         (shape->h != shaper->window->h) ) {
74         return SDL_INVALID_SHAPE_ARGUMENT;
75     }
76 
77     data = (SDL_ShapeData*)shaper->driverdata;
78     if(data->mask_tree != NULL)
79         SDL_FreeShapeTree(&data->mask_tree);
80     data->mask_tree = SDL_CalculateShapeTree(*shape_mode,shape);
81 
82     SDL_TraverseShapeTree(data->mask_tree,&CombineRectRegions,&mask_region);
83     SDL_assert(mask_region != NULL);
84 
85     SetWindowRgn(((SDL_WindowData *)(shaper->window->driverdata))->hwnd, mask_region, TRUE);
86 
87     return 0;
88 }
89 
90 int
Win32_ResizeWindowShape(SDL_Window * window)91 Win32_ResizeWindowShape(SDL_Window *window) {
92     SDL_ShapeData* data;
93 
94     if (window == NULL)
95         return -1;
96     data = (SDL_ShapeData *)window->shaper->driverdata;
97     if (data == NULL)
98         return -1;
99 
100     if(data->mask_tree != NULL)
101         SDL_FreeShapeTree(&data->mask_tree);
102     if(window->shaper->hasshape == SDL_TRUE) {
103         window->shaper->userx = window->x;
104         window->shaper->usery = window->y;
105         SDL_SetWindowPosition(window,-1000,-1000);
106     }
107 
108     return 0;
109 }
110 
111 #endif /* SDL_VIDEO_DRIVER_WINDOWS */
112