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#include <stdlib.h>
25
26namespace sw
27{
28 static int (*PreviousXErrorHandler)(Display *display, XErrorEvent *event) = 0;
29 static bool shmBadAccess = false;
30
31 // Catches BadAcces errors so we can fall back to not using MIT-SHM
32 static int XShmErrorHandler(Display *display, XErrorEvent *event)
33 {
34 if(event->error_code == BadAccess)
35 {
36 shmBadAccess = true;
37 return 0;
38 }
39 else
40 {
41 return PreviousXErrorHandler(display, event);
42 }
43 }
44
45 FrameBufferX11::FrameBufferX11(Display *display, Window window, int width, int height) : FrameBuffer(width, height, false, false), ownX11(!display), x_display(display), x_window(window)
46 {
47 if(!x_display)
48 {
49 x_display = libX11->XOpenDisplay(0);
50 assert(x_display);
51 }
52
53 int screen = DefaultScreen(x_display);
54 x_gc = libX11->XDefaultGC(x_display, screen);
55 int depth = libX11->XDefaultDepth(x_display, screen);
56
57 XVisualInfo x_visual;
58 Status status = libX11->XMatchVisualInfo(x_display, screen, 32, TrueColor, &x_visual);
59 bool match = (status != 0 && x_visual.blue_mask == 0xFF); // Prefer X8R8G8B8
60 Visual *visual = match ? x_visual.visual : libX11->XDefaultVisual(x_display, screen);
61
62 mit_shm = (libX11->XShmQueryExtension && libX11->XShmQueryExtension(x_display) == True);
63
64 if(mit_shm)
65 {
66 x_image = libX11->XShmCreateImage(x_display, visual, depth, ZPixmap, 0, &shminfo, width, height);
67
68 shminfo.shmid = shmget(IPC_PRIVATE, x_image->bytes_per_line * x_image->height, IPC_CREAT | SHM_R | SHM_W);
69 shminfo.shmaddr = x_image->data = (char*)shmat(shminfo.shmid, 0, 0);
70 shminfo.readOnly = False;
71
72 PreviousXErrorHandler = libX11->XSetErrorHandler(XShmErrorHandler);
73 libX11->XShmAttach(x_display, &shminfo); // May produce a BadAccess error
74 libX11->XSync(x_display, False);
75 libX11->XSetErrorHandler(PreviousXErrorHandler);
76
77 if(shmBadAccess)
78 {
79 mit_shm = false;
80
81 XDestroyImage(x_image);
82 shmdt(shminfo.shmaddr);
83 shmctl(shminfo.shmid, IPC_RMID, 0);
84
85 shmBadAccess = false;
86 }
87 }
88
89 if(!mit_shm)
90 {
91 int bytes_per_line = width * 4;
92 int bytes_per_image = height * bytes_per_line;
93 char *buffer = (char*)malloc(bytes_per_image);
94 memset(buffer, 0, bytes_per_image);
95
96 x_image = libX11->XCreateImage(x_display, visual, depth, ZPixmap, 0, buffer, width, height, 32, bytes_per_line);
97 assert(x_image);
98
99 if(!x_image)
100 {
101 free(buffer);
102 }
103 }
104 }
105
106 FrameBufferX11::~FrameBufferX11()
107 {
108 if(!mit_shm)
109 {
110 XDestroyImage(x_image);
111 }
112 else
113 {
114 libX11->XShmDetach(x_display, &shminfo);
115 XDestroyImage(x_image);
116 shmdt(shminfo.shmaddr);
117 shmctl(shminfo.shmid, IPC_RMID, 0);
118 }
119
120 if(ownX11)
121 {
122 libX11->XCloseDisplay(x_display);
123 }
124 }
125
126 void *FrameBufferX11::lock()
127 {
128 if(x_image)
129 {
130 stride = x_image->bytes_per_line;
131 framebuffer = x_image->data;
132 }
133
134 return framebuffer;
135 }
136
137 void FrameBufferX11::unlock()
138 {
139 framebuffer = nullptr;
140 }
141
142 void FrameBufferX11::blit(sw::Surface *source, const Rect *sourceRect, const Rect *destRect)
143 {
144 copy(source);
145
146 if(!mit_shm)
147 {
148 libX11->XPutImage(x_display, x_window, x_gc, x_image, 0, 0, 0, 0, width, height);
149 }
150 else
151 {
152 libX11->XShmPutImage(x_display, x_window, x_gc, x_image, 0, 0, 0, 0, width, height, False);
153 }
154
155 libX11->XSync(x_display, False);
156
157 if(false) // Draw the framerate on screen
158 {
159 static double fpsTime = sw::Timer::seconds();
160 static int frames = -1;
161
162 double time = sw::Timer::seconds();
163 double delta = time - fpsTime;
164 frames++;
165
166 static double FPS = 0.0;
167 static double maxFPS = 0.0;
168
169 if(delta > 1.0)
170 {
171 FPS = frames / delta;
172
173 fpsTime = time;
174 frames = 0;
175
176 if(FPS > maxFPS)
177 {
178 maxFPS = FPS;
179 }
180 }
181
182 char string[256];
183 sprintf(string, "FPS: %.2f (max: %.2f)", FPS, maxFPS);
184 libX11->XDrawString(x_display, x_window, x_gc, 50, 50, string, strlen(string));
185 }
186 }
187}
188
189NO_SANITIZE_FUNCTION sw::FrameBuffer *createFrameBuffer(void *display, Window window, int width, int height)
190{
191 return new sw::FrameBufferX11((::Display*)display, window, width, height);
192}
193