1/*
2 * Copyright (C) 2012 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 *      http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17#include <stdint.h>
18#include <sys/types.h>
19
20#include <fcntl.h>
21#include <sys/ioctl.h>
22#include <linux/fb.h>
23#include <linux/input.h>
24#include <errno.h>
25#include <string.h>
26#include <stdio.h>
27#include <cutils/memory.h>
28#include <asm-generic/mman.h>
29#include <sys/mman.h>
30#include <utils/threads.h>
31#include <unistd.h>
32#include <math.h>
33
34using namespace android;
35
36#ifndef FBIO_WAITFORVSYNC
37#define FBIO_WAITFORVSYNC   _IOW('F', 0x20, __u32)
38#endif
39
40struct Buffer {
41    size_t w;
42    size_t h;
43    size_t s;
44    union {
45        void* addr;
46        uint32_t* pixels;
47    };
48};
49
50void clearBuffer(Buffer* buf, uint32_t pixel) {
51    android_memset32(buf->pixels, pixel, buf->s * buf->h * 4);
52}
53
54void drawTwoPixels(Buffer* buf, uint32_t pixel, ssize_t x, ssize_t y, size_t w) {
55    if (y>0 && y<ssize_t(buf->h)) {
56        uint32_t* bits = buf->pixels + y * buf->s;
57        if (x>=0 && x<ssize_t(buf->w)) {
58            bits[x] = pixel;
59        }
60        ssize_t W(w);
61        if ((x+W)>=0 && (x+W)<ssize_t(buf->w)) {
62            bits[x+W] = pixel;
63        }
64    }
65}
66
67void drawHLine(Buffer* buf, uint32_t pixel, ssize_t x, ssize_t y, size_t w) {
68    if (y>0 && y<ssize_t(buf->h)) {
69        ssize_t W(w);
70        if (x<0) {
71            W += x;
72            x = 0;
73        }
74        if (x+w > buf->w) {
75            W = buf->w - x;
76        }
77        if (W>0) {
78            uint32_t* bits = buf->pixels + y * buf->s + x;
79            android_memset32(bits, pixel, W*4);
80        }
81    }
82}
83
84void drawRect(Buffer* buf, uint32_t pixel, ssize_t x, ssize_t y, size_t w, size_t h) {
85    ssize_t W(w), H(h);
86    if (x<0) {
87        w += x;
88        x = 0;
89    }
90    if (y<0) {
91        h += y;
92        y = 0;
93    }
94    if (x+w > buf->w)   W = buf->w - x;
95    if (y+h > buf->h)   H = buf->h - y;
96    if (W>0 && H>0) {
97        uint32_t* bits = buf->pixels + y * buf->s + x;
98        for (ssize_t i=0 ; i<H ; i++) {
99            android_memset32(bits, pixel, W*4);
100            bits += buf->s;
101        }
102    }
103}
104
105void drawCircle(Buffer* buf, uint32_t pixel,
106        size_t x0, size_t y0, size_t radius, bool filled = false) {
107    ssize_t f = 1 - radius;
108    ssize_t ddF_x = 1;
109    ssize_t ddF_y = -2 * radius;
110    ssize_t x = 0;
111    ssize_t y = radius;
112    if (filled) {
113        drawHLine(buf, pixel, x0-radius, y0, 2*radius);
114    } else {
115        drawTwoPixels(buf, pixel, x0-radius, y0, 2*radius);
116    }
117    while (x < y) {
118        if (f >= 0) {
119            y--;
120            ddF_y += 2;
121            f += ddF_y;
122        }
123        x++;
124        ddF_x += 2;
125        f += ddF_x;
126        if (filled) {
127            drawHLine(buf, pixel, x0-x, y0+y, 2*x);
128            drawHLine(buf, pixel, x0-x, y0-y, 2*x);
129            drawHLine(buf, pixel, x0-y, y0+x, 2*y);
130            drawHLine(buf, pixel, x0-y, y0-x, 2*y);
131        } else {
132            drawTwoPixels(buf, pixel, x0-x, y0+y, 2*x);
133            drawTwoPixels(buf, pixel, x0-x, y0-y, 2*x);
134            drawTwoPixels(buf, pixel, x0-y, y0+x, 2*y);
135            drawTwoPixels(buf, pixel, x0-y, y0-x, 2*y);
136        }
137    }
138}
139
140class TouchEvents {
141    class EventThread : public Thread {
142        int fd;
143
144        virtual bool threadLoop() {
145            input_event event;
146            int first_down = 0;
147            do {
148                read(fd, &event, sizeof(event));
149                if (event.type == EV_ABS) {
150                    if (event.code == ABS_MT_TRACKING_ID) {
151                        down = event.value == -1 ? 0 : 1;
152                        first_down = down;
153                    }
154                    if (event.code == ABS_MT_POSITION_X) {
155                        x = event.value;
156                    }
157                    if (event.code == ABS_MT_POSITION_Y) {
158                        y = event.value;
159                    }
160                }
161            } while (event.type == EV_SYN);
162            return true;
163        }
164
165    public:
166        int x, y, down;
167        EventThread() : Thread(false),
168                x(0), y(0), down(0)
169        {
170            fd = open("/dev/input/event1", O_RDONLY);
171        }
172};
173    sp<EventThread> thread;
174
175public:
176    TouchEvents() {
177        thread = new EventThread();
178        thread->run("EventThread", PRIORITY_URGENT_DISPLAY);
179    }
180
181    int getMostRecentPosition(int* x, int* y) {
182        *x = thread->x;
183        *y = thread->y;
184        return thread->down;
185    }
186};
187
188
189struct Queue {
190    struct position {
191        int x, y;
192    };
193    int index;
194    position q[16];
195    Queue() : index(0) { }
196    void push(int x, int y) {
197        index++;
198        index &= 0xF;
199        q[index].x = x;
200        q[index].y = y;
201    }
202    void get(int lag, int* x, int* y) {
203        const int i = (index - lag) & 0xF;
204        *x = q[i].x;
205        *y = q[i].y;
206    }
207};
208
209extern char *optarg;
210extern int optind;
211extern int optopt;
212extern int opterr;
213extern int optreset;
214
215void usage(const char* name) {
216    printf("\nusage: %s [-h] [-l lag]\n", name);
217}
218
219int main(int argc, char** argv) {
220    fb_var_screeninfo vi;
221    fb_fix_screeninfo fi;
222
223    int lag = 0;
224    int fd = open("/dev/graphics/fb0", O_RDWR);
225    ioctl(fd, FBIOGET_VSCREENINFO, &vi);
226    ioctl(fd, FBIOGET_FSCREENINFO, &fi);
227    void* bits = mmap(0, fi.smem_len, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0);
228    Buffer framebuffer;
229    framebuffer.w = vi.xres;
230    framebuffer.h = vi.yres;
231    framebuffer.s = fi.line_length / (vi.bits_per_pixel >> 3);
232    framebuffer.addr = bits;
233
234    int ch;
235    while ((ch = getopt(argc, argv, "hl:")) != -1) {
236        switch (ch) {
237            case 'l':
238                lag = atoi(optarg);
239                break;
240            case 'h':
241            default:
242                usage(argv[0]);
243                exit(0);
244        }
245    }
246    argc -= optind;
247    argv += optind;
248
249
250    TouchEvents touch;
251    Queue queue;
252
253
254    int x=0, y=0;
255    int lag_x=0, lag_y=0;
256
257    clearBuffer(&framebuffer, 0);
258    while (true) {
259        uint32_t crt = 0;
260        ioctl(fd, FBIO_WAITFORVSYNC, &crt);
261
262        // draw beam marker
263        drawRect(&framebuffer, 0x400000, framebuffer.w-2, 0, 2, framebuffer.h);
264        // erase screen
265        if (lag) {
266            drawCircle(&framebuffer, 0, lag_x, lag_y, 100);
267            drawHLine(&framebuffer, 0, 0, lag_y, 32);
268        }
269        drawCircle(&framebuffer, 0, x, y, 100, true);
270        drawHLine(&framebuffer, 0, 0, y, 32);
271
272        // draw a line at y=1000
273        drawHLine(&framebuffer, 0x808080, 0, 1000, framebuffer.w);
274
275        // get touch events
276        touch.getMostRecentPosition(&x, &y);
277        queue.push(x, y);
278        queue.get(lag, &lag_x, &lag_y);
279
280        if (lag) {
281            drawCircle(&framebuffer, 0x00FF00, lag_x, lag_y, 100);
282            drawHLine(&framebuffer, 0x00FF00, 0, lag_y, 32);
283        }
284
285        drawCircle(&framebuffer, 0xFFFFFF, x, y, 100, true);
286        drawHLine(&framebuffer, 0xFFFFFF, 0, y, 32);
287
288        // draw end of frame beam marker
289        drawRect(&framebuffer, 0x004000, framebuffer.w-2, 0, 2, framebuffer.h);
290    }
291
292    close(fd);
293    return 0;
294}
295