1 // Copyright 2016 The SwiftShader Authors. All Rights Reserved.
2 //
3 // Licensed under the Apache License, Version 2.0 (the "License");
4 // you may not use this file except in compliance with the License.
5 // You may obtain a copy of the License at
6 //
7 // http://www.apache.org/licenses/LICENSE-2.0
8 //
9 // Unless required by applicable law or agreed to in writing, software
10 // distributed under the License is distributed on an "AS IS" BASIS,
11 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12 // See the License for the specific language governing permissions and
13 // limitations under the License.
14
15 #include "FrameBufferX11.hpp"
16
17 #include "libX11.hpp"
18 #include "Common/Timer.hpp"
19
20 #include <sys/ipc.h>
21 #include <sys/shm.h>
22 #include <string.h>
23 #include <assert.h>
24
25 namespace sw
26 {
27 static int (*PreviousXErrorHandler)(Display *display, XErrorEvent *event) = 0;
28 static bool shmBadAccess = false;
29
30 // Catches BadAcces errors so we can fall back to not using MIT-SHM
XShmErrorHandler(Display * display,XErrorEvent * event)31 static int XShmErrorHandler(Display *display, XErrorEvent *event)
32 {
33 if(event->error_code == BadAccess)
34 {
35 shmBadAccess = true;
36 return 0;
37 }
38 else
39 {
40 return PreviousXErrorHandler(display, event);
41 }
42 }
43
FrameBufferX11(Display * display,Window window,int width,int height)44 FrameBufferX11::FrameBufferX11(Display *display, Window window, int width, int height) : FrameBuffer(width, height, false, false), ownX11(!display), x_display(display), x_window(window)
45 {
46 if(!x_display)
47 {
48 x_display = libX11->XOpenDisplay(0);
49 }
50
51 int screen = DefaultScreen(x_display);
52 x_gc = libX11->XDefaultGC(x_display, screen);
53 int depth = libX11->XDefaultDepth(x_display, screen);
54
55 Status status = libX11->XMatchVisualInfo(x_display, screen, 32, TrueColor, &x_visual);
56 bool match = (status != 0 && x_visual.blue_mask == 0xFF); // Prefer X8R8G8B8
57 Visual *visual = match ? x_visual.visual : libX11->XDefaultVisual(x_display, screen);
58
59 mit_shm = (libX11->XShmQueryExtension && libX11->XShmQueryExtension(x_display) == True);
60
61 if(mit_shm)
62 {
63 x_image = libX11->XShmCreateImage(x_display, visual, depth, ZPixmap, 0, &shminfo, width, height);
64
65 shminfo.shmid = shmget(IPC_PRIVATE, x_image->bytes_per_line * x_image->height, IPC_CREAT | SHM_R | SHM_W);
66 shminfo.shmaddr = x_image->data = buffer = (char*)shmat(shminfo.shmid, 0, 0);
67 shminfo.readOnly = False;
68
69 PreviousXErrorHandler = libX11->XSetErrorHandler(XShmErrorHandler);
70 libX11->XShmAttach(x_display, &shminfo); // May produce a BadAccess error
71 libX11->XSync(x_display, False);
72 libX11->XSetErrorHandler(PreviousXErrorHandler);
73
74 if(shmBadAccess)
75 {
76 mit_shm = false;
77
78 XDestroyImage(x_image);
79 shmdt(shminfo.shmaddr);
80 shmctl(shminfo.shmid, IPC_RMID, 0);
81
82 shmBadAccess = false;
83 }
84 }
85
86 if(!mit_shm)
87 {
88 int bytes_per_line = width * 4;
89 int bytes_per_image = height * bytes_per_line;
90 buffer = new char[bytes_per_image];
91 memset(buffer, 0, bytes_per_image);
92 x_image = libX11->XCreateImage(x_display, visual, depth, ZPixmap, 0, buffer, width, height, 32, bytes_per_line);
93 }
94 }
95
~FrameBufferX11()96 FrameBufferX11::~FrameBufferX11()
97 {
98 if(!mit_shm)
99 {
100 x_image->data = 0;
101 XDestroyImage(x_image);
102
103 delete[] buffer;
104 buffer = 0;
105 }
106 else
107 {
108 libX11->XShmDetach(x_display, &shminfo);
109 XDestroyImage(x_image);
110 shmdt(shminfo.shmaddr);
111 shmctl(shminfo.shmid, IPC_RMID, 0);
112 }
113
114 if(ownX11)
115 {
116 libX11->XCloseDisplay(x_display);
117 }
118 }
119
lock()120 void *FrameBufferX11::lock()
121 {
122 stride = x_image->bytes_per_line;
123 framebuffer = buffer;
124
125 return framebuffer;
126 }
127
unlock()128 void FrameBufferX11::unlock()
129 {
130 framebuffer = nullptr;
131 }
132
blit(sw::Surface * source,const Rect * sourceRect,const Rect * destRect)133 void FrameBufferX11::blit(sw::Surface *source, const Rect *sourceRect, const Rect *destRect)
134 {
135 copy(source);
136
137 if(!mit_shm)
138 {
139 libX11->XPutImage(x_display, x_window, x_gc, x_image, 0, 0, 0, 0, width, height);
140 }
141 else
142 {
143 libX11->XShmPutImage(x_display, x_window, x_gc, x_image, 0, 0, 0, 0, width, height, False);
144 }
145
146 libX11->XSync(x_display, False);
147
148 if(false) // Draw the framerate on screen
149 {
150 static double fpsTime = sw::Timer::seconds();
151 static int frames = -1;
152
153 double time = sw::Timer::seconds();
154 double delta = time - fpsTime;
155 frames++;
156
157 static double FPS = 0.0;
158 static double maxFPS = 0.0;
159
160 if(delta > 1.0)
161 {
162 FPS = frames / delta;
163
164 fpsTime = time;
165 frames = 0;
166
167 if(FPS > maxFPS)
168 {
169 maxFPS = FPS;
170 }
171 }
172
173 char string[256];
174 sprintf(string, "FPS: %.2f (max: %.2f)", FPS, maxFPS);
175 libX11->XDrawString(x_display, x_window, x_gc, 50, 50, string, strlen(string));
176 }
177 }
178 }
179
createFrameBuffer(void * display,Window window,int width,int height)180 NO_SANITIZE_FUNCTION sw::FrameBuffer *createFrameBuffer(void *display, Window window, int width, int height)
181 {
182 return new sw::FrameBufferX11((::Display*)display, window, width, height);
183 }
184