FrameBufferX11.cpp revision 708c24b3cd03b68aa98b29a9099d6a9ce96eca16 
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
25namespace 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
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
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
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
120	void *FrameBufferX11::lock()
121	{
122		stride = x_image->bytes_per_line;
123		locked = buffer;
124
125		return locked;
126	}
127
128	void FrameBufferX11::unlock()
129	{
130		locked = nullptr;
131	}
132
133	void FrameBufferX11::blit(void *source, const Rect *sourceRect, const Rect *destRect, Format sourceFormat, size_t sourceStride)
134	{
135		copy(source, sourceFormat, sourceStride);
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
180NO_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