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      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 
     34 using namespace android;
     35 
     36 #ifndef FBIO_WAITFORVSYNC
     37 #define FBIO_WAITFORVSYNC   _IOW('F', 0x20, __u32)
     38 #endif
     39 
     40 struct 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 
     50 void clearBuffer(Buffer* buf, uint32_t pixel) {
     51     android_memset32(buf->pixels, pixel, buf->s * buf->h * 4);
     52 }
     53 
     54 void 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<buf->w) {
     58             bits[x] = pixel;
     59         }
     60         ssize_t W(w);
     61         if ((x+W)>=0 && (x+W)<buf->w) {
     62             bits[x+W] = pixel;
     63         }
     64     }
     65 }
     66 
     67 void 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 
     84 void 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 
    105 void 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 
    140 class 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 
    175 public:
    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 
    189 struct 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 
    209 extern char *optarg;
    210 extern int optind;
    211 extern int optopt;
    212 extern int opterr;
    213 extern int optreset;
    214 
    215 void usage(const char* name) {
    216     printf("\nusage: %s [-h] [-l lag]\n", name);
    217 }
    218 
    219 int 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, down=0;
    255     int lag_x=0, lag_y=0;
    256 
    257     clearBuffer(&framebuffer, 0);
    258     while (true) {
    259         uint32_t crt = 0;
    260         int err = 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