[commit] r2210 - add platform code for CameraPlugin

Previous Topic Next Topic
 
classic Classic list List threaded Threaded
1 message Options
Reply | Threaded
Open this post in threaded view
|

[commit] r2210 - add platform code for CameraPlugin

commits-3
 
Author: piumarta
Date: 2010-05-13 18:17:23 -0700 (Thu, 13 May 2010)
New Revision: 2210

Added:
   trunk/platforms/unix/plugins/CameraPlugin/
   trunk/platforms/unix/plugins/CameraPlugin/sqCamera.c
Modified:
   trunk/platforms/unix/ChangeLog
Log:
add platform code for CameraPlugin

Modified: trunk/platforms/unix/ChangeLog
===================================================================
--- trunk/platforms/unix/ChangeLog 2010-05-13 21:18:47 UTC (rev 2209)
+++ trunk/platforms/unix/ChangeLog 2010-05-14 01:17:23 UTC (rev 2210)
@@ -1,5 +1,7 @@
 2010-05-13  Ian Piumarta  <com -dot- gmail -at- piumarta (backwards)>
 
+ * plugins/CameraPlugin/sqCamera.c: Added.
+
  * npsqueak/npsqueakrun.in (realpath): prepend dir to link target
  iff target is relative.
 

Added: trunk/platforms/unix/plugins/CameraPlugin/sqCamera.c
===================================================================
--- trunk/platforms/unix/plugins/CameraPlugin/sqCamera.c                        (rev 0)
+++ trunk/platforms/unix/plugins/CameraPlugin/sqCamera.c 2010-05-14 01:17:23 UTC (rev 2210)
@@ -0,0 +1,796 @@
+/*
+ *  V4L2 for Scratch (Derek O'Connell, 2009)
+ *
+ *  This code can be used and distributed without restrictions.
+ *
+ */
+
+#include "sq.h"
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <assert.h>
+
+#include <getopt.h>   /* getopt_long() */
+
+#include <fcntl.h>    /* low-level i/o */
+#include <unistd.h>
+#include <errno.h>
+#include <malloc.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <sys/time.h>
+#include <sys/mman.h>
+#include <sys/ioctl.h>
+#include <dlfcn.h>
+
+#include <asm/types.h>  /* for videodev2.h */
+
+#include <linux/videodev2.h>
+
+/* >>>>>>>>>>>>>>>>>>>>>>>>>>>>>> */
+/*
+#define USE_LIBV4L2x
+#ifdef USE_LIBV4L2
+#include <libv4l2.h>
+#endif
+*/
+
+void *hLibv4l2 = NULL;
+
+int (*vd_open)(const char *, int, ...);
+int (*vd_close)(int);
+int (*vd_dup)(int);
+int (*vd_ioctl)(int, unsigned long int, ...);
+ssize_t (*vd_read)(int, void *, size_t);
+void * (*vd_mmap)(void *, size_t, int, int, int, int64_t);
+int (*vd_munmap)(void *, size_t);
+
+/* <<<<<<<<<<<<<<<<<<<<<<<<<<<<<< */
+
+
+#define CLEAR(x) memset (&(x), 0, sizeof (x))
+
+typedef enum {
+ IO_METHOD_READ,
+ IO_METHOD_MMAP,
+ IO_METHOD_USERPTR,
+} io_method;
+
+struct buffer {
+ void *  start;
+ size_t  length;
+};
+
+
+struct camInfo_t {
+ int devNum;
+ int fileDesc;
+ int bmWidth, bmHeight;
+
+ io_method ioMethod;
+ int pixelformat;
+ struct buffer * buffers;
+ unsigned int nBuffers;
+
+ struct v4l2_buffer read_buf;
+
+ void *sqBuffer;
+ long sqBufferBytes;
+ long sqPixels;
+
+ long frameCount;
+} camInfo[10];
+
+typedef struct camInfo_t *camPtr;
+
+static char * videoDevName0 = "/dev/video0";
+
+/* ================================== FUNCTION PROTOTYPES */
+
+/* LIBRARY CONSTRUCTOR/DESCTRUCTOR */
+
+void __attribute__ ((constructor)) libCon(void);
+void __attribute__ ((destructor)) libDes(void);
+
+
+/* UTILITY */
+
+inline int camIsOpen(  camPtr cam) { return (-1 != cam->fileDesc); }
+inline int camIsClosed(camPtr cam) { return (-1 == cam->fileDesc); }
+
+
+/* V4L ACCESS */
+
+
+/* SQUEAK INTERFACE */
+
+sqInt CameraGetParam(int camNum, int paramNum);
+sqInt CameraGetFrame(int camNum, unsigned char* buf, int pixelCount);
+sqInt CameraExtent(int camNum);
+char* CameraName(int camNum);
+void CameraClose(int camNum);
+sqInt CameraOpen(int camNum, int frameWidth, int frameHeight);
+
+
+/* ================================== ??? */
+
+
+/* LIBRARY CONSTRUCTOR/DESCTRUCTOR */
+
+void __attribute__ ((constructor))
+libCon(void)
+{
+  int devNum;
+  camPtr cam;
+
+  vd_open = open;
+  vd_close = close;
+  vd_dup = dup;
+  vd_ioctl = ioctl;
+  vd_read = read;
+  vd_mmap = mmap;
+  vd_munmap = munmap;
+
+/*  printf("libv4l2: use if available...");
+*/
+hLibv4l2 = dlopen("libv4l2.so", RTLD_LAZY);
+  if (hLibv4l2)
+  {
+/*  printf("yay!\n");
+*/  
+  vd_open = dlsym(hLibv4l2, "v4l2_open");
+  vd_close = dlsym(hLibv4l2, "v4l2_close");
+  vd_dup = dlsym(hLibv4l2, "v4l2_dup");
+  vd_ioctl = dlsym(hLibv4l2, "v4l2_ioctl");
+  vd_read = dlsym(hLibv4l2, "v4l2_read");
+  vd_mmap = dlsym(hLibv4l2, "v4l2_mmap");
+  vd_munmap = dlsym(hLibv4l2, "v4l2_munmap");
+  } else {
+/*  printf("nay, %s\n", dlerror());
+*/
+  }
+
+  for (devNum = 0; devNum < 10; ++devNum) {
+ cam = &camInfo[devNum];
+
+ CLEAR(*cam);
+
+ cam->devNum = devNum;
+ cam->fileDesc = -1;
+ cam->ioMethod = IO_METHOD_MMAP;
+ cam->read_buf.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
+ cam->read_buf.memory = V4L2_MEMORY_MMAP;
+ cam->nBuffers = 1;
+
+/* Pixel format now auto selected according to ease/speed of conversion
+ cam->pixelformat = V4L2_PIX_FMT_YUYV;
+ cam->pixelformat = V4L2_PIX_FMT_RGB24;
+*/
+
+/*
+ cam->fileDesc = 0;
+ cam->bmWidth = 0;
+ cam->bmHeight = 0;
+ cam->buffers = NULL;
+ cam->nBuffers = 0;
+ cam->read_buf = NULL;
+ cam->sqBuffer = 0;
+ cam->sqBufferBytes = 0;
+ cam->sqPixels = 0;
+ cam->frameCount = 0;
+*/
+  }
+}
+
+void __attribute__ ((destructor))
+libDes(void)
+{
+  int camNum;
+  for (camNum = 1; camNum < 11; ++camNum)
+  CameraClose(camNum);
+/*  
+  if (hLibv4l2)
+  dlclose(hLibv4l2);
+*/
+}
+
+
+/* V4L ACCESS */
+
+static int
+xioctl (camPtr cam, int request, void * arg)
+{
+ int r;
+
+ do r = vd_ioctl (cam->fileDesc, request, arg);
+  while (-1 == r && EINTR == errno);
+
+ return r;
+}
+
+
+/* >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
+  from: palettes.c in VideoForLinuxPlugin
+  from: http://en.wikipedia.org/wiki/YUV422
+
+  Originally (here) a quick hack for XO-1 but libv4l
+  version worked anyway.
+  >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> */
+
+inline unsigned char clipPixel(const int pixel) {
+    int result;
+
+    result = ((pixel < 0) ? 0 : pixel);
+    return (unsigned char) ((result > 255) ? 255: result);
+}
+
+inline void
+convertPixelYUV444toARGB32(
+   const unsigned char y,
+               const unsigned char u,
+               const unsigned char v,
+               unsigned char* dest)
+{
+    const int C = (y - 16) * 298 + 128;
+    const int D = u - 128;
+    const int E = v - 128;
+
+    /* ARGB */
+    dest[0] = clipPixel(( C + 516 * D          ) >> 8);
+    dest[1] = clipPixel(( C - 100 * D - 208 * E) >> 8);
+    dest[2] = clipPixel(( C           + 409 * E) >> 8);
+    dest[3] = 255;
+
+}
+
+inline void
+convertImageYUYVToARGB32 (camPtr cam, int bufIdx)
+{
+ int i;
+
+ const unsigned char* src = cam->buffers[bufIdx].start;
+ unsigned char* dst = cam->sqBuffer;
+ unsigned long int *pdst;
+ unsigned long int pixelCount = cam->sqPixels;
+
+ unsigned char u, y1, v, y2;
+
+ for (i = 0; i < pixelCount; i += 2) {
+ y1 = *src++;
+ u  = *src++;
+ y2 = *src++;
+ v  = *src++;
+
+ convertPixelYUV444toARGB32(y1, u, v, dst);
+ pdst = (unsigned long *)dst;
+ dst += 4;
+
+ if (y2 == y1)
+  *(unsigned long *)dst = *pdst;
+ else
+  convertPixelYUV444toARGB32(y2, u, v, dst);
+
+ dst += 4;
+ }
+}
+
+/* <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<< */
+
+static void
+convertImageRGB24toARGB32 (camPtr cam, int bufIdx) /* const void *src, const void *dst) */
+{
+ unsigned char  *src = cam->buffers[bufIdx].start;
+ unsigned long int *dst = cam->sqBuffer;
+ unsigned long int pixelCount = cam->sqPixels;
+ unsigned long int pixel;
+ int i;
+
+ if (0 == dst) return;
+
+ for ( i = 0; i < pixelCount; i++) {
+ pixel = 0xFF000000 | (*src++ << 16);
+ pixel = pixel | (*src++ << 8);
+ *dst++  = pixel | *src++;
+ }
+}
+
+
+static void
+convertImageRGB444toARGB32 (camPtr cam, int bufIdx) /* const void *src, const void *dst) */
+{
+ unsigned char  *src = cam->buffers[bufIdx].start;
+ unsigned long int *dst = cam->sqBuffer;
+ unsigned long int pixelCount = cam->sqPixels;
+ unsigned long int r,g,b,pixel;
+ int i;
+
+ if (0 == dst) return;
+
+ /* Byte0: (g)ggg(b)bbb, Byte1: xxxx(r)rrr */
+
+ for ( i = 0; i < pixelCount; i++) {
+  r = *src << 4;
+  g = *src++ & 0xF0;
+  b = (*src++ & 0x0F) << 4;
+  pixel = 0xFF000000;
+  pixel |= (r << 16);
+  pixel |= (g <<  8);
+  pixel |= b;
+  *dst++ = pixel;
+ }
+}
+
+
+static void
+convertImageRGB565toARGB32 (camPtr cam, int bufIdx) /* const void *src, const void *dst) */
+{
+ unsigned char  *src = cam->buffers[bufIdx].start;
+ unsigned long int *dst = cam->sqBuffer;
+ unsigned long int pixelCount = cam->sqPixels;
+ unsigned long int r,g,b,pixel;
+ int i;
+
+ if (0 == dst) return;
+
+ /* Byte0: ggg(r)rrrr, Byte1: (b)bbbb(g)gg */
+
+ for ( i = 0; i < pixelCount; i++) {
+  r = (*src & 0x1F) << 3;
+  g = (*src++ & 0xE0) >> 5;
+  g |= (*src & 0x07) << 5;
+  b = *src++ & 0xF8;
+  pixel = 0xFF000000;
+  pixel |= (b << 16);
+  pixel |= (g <<  8);
+  pixel |= r;
+  *dst++ = pixel;
+ }
+}
+
+
+void
+convertImage (camPtr cam, int bufIdx)
+{
+ /* func pts to be used at later date */
+  
+ if (cam->pixelformat == V4L2_PIX_FMT_YUYV) {
+ convertImageYUYVToARGB32 (cam, bufIdx);
+ return;
+ }
+
+ if (cam->pixelformat == V4L2_PIX_FMT_RGB565) {
+ convertImageRGB565toARGB32 (cam, bufIdx);
+ return;
+ }
+
+ if (cam->pixelformat == V4L2_PIX_FMT_RGB444) {
+ convertImageRGB444toARGB32 (cam, bufIdx);
+ return;
+ }
+
+ if (cam->pixelformat == V4L2_PIX_FMT_RGB24) {
+ convertImageRGB24toARGB32 (cam, bufIdx);
+ return;
+ }
+}
+
+
+static int
+read_frame (camPtr cam)
+{
+ struct v4l2_buffer buf;
+
+ cam->frameCount += 1;
+
+ CLEAR (buf);
+ buf.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
+ buf.memory = V4L2_MEMORY_MMAP;
+
+ if (-1 == xioctl (cam, VIDIOC_DQBUF, &buf)) {
+ switch (errno) {
+ case EAGAIN:
+ case EIO:
+ return 0;
+ default:
+ return -1;
+ }
+ }
+
+ if (buf.index < cam->nBuffers)
+ convertImage (cam, buf.index);
+
+ if (-1 == xioctl (cam, VIDIOC_QBUF, &buf)) return -1;
+
+ return 0;
+}
+
+
+static int
+getFrame(camPtr cam)
+{
+ int fd = cam->fileDesc;
+ unsigned int retry;
+ fd_set fds;
+ struct timeval tv;
+ int r;
+
+ retry = 1;
+
+ while (retry-- > 0) {
+ FD_ZERO (&fds);
+ FD_SET (fd, &fds);
+
+ /* Timeout. */
+ tv.tv_sec = 1;
+ tv.tv_usec = 0;
+
+ r = select (fd + 1, &fds, NULL, NULL, &tv);
+
+ if (-1 == r) {
+ if (EINTR == errno)
+ continue;
+
+ return -1;
+ }
+
+ if (0 == r) return -1;
+ if (0 == read_frame (cam)) return 0;
+
+ /* EAGAIN - retry */
+ }
+}
+
+
+static int
+stream_off (camPtr cam)
+{
+ enum v4l2_buf_type type;
+ type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
+ xioctl (cam, VIDIOC_STREAMOFF, &type);
+ return 0;
+}
+
+
+static int
+stream_on (camPtr cam)
+{
+ enum v4l2_buf_type type;
+ type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
+ if (-1 == xioctl (cam, VIDIOC_STREAMON, &type)) return -1;
+ return 0;
+}
+
+
+static int
+uninit_device (camPtr cam)
+{
+ unsigned int i;
+
+ for (i = 0; i < cam->nBuffers; ++i)
+ if (-1 == vd_munmap (cam->buffers[i].start, cam->buffers[i].length))
+ return -1;
+
+ free (cam->buffers);
+ return 0;
+}
+
+
+static int
+queue_buffers (camPtr cam)
+{
+ unsigned int i;
+
+ for (i = 0; i < cam->nBuffers; ++i) {
+ struct v4l2_buffer buf;
+
+ CLEAR (buf);
+ buf.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
+ buf.memory = V4L2_MEMORY_MMAP;
+ buf.index = i;
+
+ if (-1 == xioctl (cam, VIDIOC_QBUF, &buf)) return -1;
+ }
+
+ return 0;
+}
+
+
+static int
+init_mmap (camPtr cam)
+{
+ struct v4l2_requestbuffers req;
+ int bufIdx;
+
+ CLEAR (req);
+ req.count = cam->nBuffers;
+ req.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
+ req.memory = V4L2_MEMORY_MMAP;
+
+ if (-1 == xioctl (cam, VIDIOC_REQBUFS, &req)) {
+ if (EINVAL == errno) {
+ return -1;
+ } else {
+ return -1;
+ }
+ }
+
+ if (req.count < 1) return -1;
+
+ cam->buffers = calloc (req.count, sizeof (*(cam->buffers)));
+ if (!cam->buffers) return -1;
+
+ for (bufIdx = 0; bufIdx < req.count; ++bufIdx) {
+ struct v4l2_buffer buf;
+
+ CLEAR (buf);
+ buf.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
+ buf.memory = V4L2_MEMORY_MMAP;
+ buf.index = bufIdx;
+
+ if (-1 == xioctl (cam, VIDIOC_QUERYBUF, &buf)) return -1;
+
+ cam->buffers[bufIdx].length = buf.length;
+ cam->buffers[bufIdx].start  = vd_mmap (NULL /* start anywhere */,
+  buf.length,
+  PROT_READ | PROT_WRITE /* required */,
+  MAP_SHARED /* recommended */,
+  cam->fileDesc,
+  buf.m.offset);
+
+ if (MAP_FAILED == cam->buffers[bufIdx].start) return -1;
+ }
+
+ return 0;
+}
+
+static int
+set_format (camPtr cam, struct v4l2_format *fmt, int pixelformat, int w, int h)
+{
+/*
+ fmt->fmt.pix.field = V4L2_FIELD_INTERLACED;
+ fmt->fmt.pix.field = V4L2_FIELD_TOP;
+*/
+
+ fmt->type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
+ fmt->fmt.pix.width = w;
+ fmt->fmt.pix.height = h;
+ fmt->fmt.pix.pixelformat = pixelformat;
+ fmt->fmt.pix.field = V4L2_FIELD_NONE; /* V4L2_FIELD_INTERLACED; */
+ if (-1 == xioctl (cam, VIDIOC_S_FMT, fmt)) return -1;
+
+ /* Note VIDIOC_S_FMT may change width and height. */
+
+ if ((w != fmt->fmt.pix.width)  |
+    (h != fmt->fmt.pix.height) |
+    (fmt->fmt.pix.pixelformat != pixelformat))
+ {
+ return -1;
+ }
+
+ cam->pixelformat = pixelformat;
+
+ return 0;
+}
+
+static int
+init_device (camPtr cam, int w, int h)
+{
+ struct v4l2_capability cap;
+ struct v4l2_cropcap cropcap;
+ struct v4l2_crop crop;
+ struct v4l2_format fmt;
+ int bpp;
+ unsigned int min;
+
+ if (-1 == xioctl (cam, VIDIOC_QUERYCAP, &cap)) {
+ if (EINVAL == errno) {
+ return -1;
+ } else {
+ return -1;
+ }
+ }
+
+ if (!(cap.capabilities & V4L2_CAP_VIDEO_CAPTURE)) return -1;
+ if (!(cap.capabilities & V4L2_CAP_STREAMING)) return -1;
+
+ /* Select video input, video standard and tune here. */
+
+ CLEAR (cropcap);
+ cropcap.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
+
+ if (0 == xioctl (cam, VIDIOC_CROPCAP, &cropcap)) {
+ crop.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
+ crop.c = cropcap.defrect; /* reset to default */
+
+ if (-1 == xioctl (cam, VIDIOC_S_CROP, &crop)) {
+ if (EINVAL == errno) {
+ /* Cropping not supported (ignored) */
+ } else {
+ /* Errors ignored. */
+ }
+ }
+ } else {
+ /* Errors ignored. */
+ }
+
+ CLEAR (fmt);
+ /* The order of preference of formats... */
+ if (-1 == set_format(cam, &fmt, V4L2_PIX_FMT_RGB24, w, h))
+  if (-1 == set_format(cam, &fmt, V4L2_PIX_FMT_YUYV, w, h))
+ if (-1 == set_format(cam, &fmt, V4L2_PIX_FMT_RGB565, w, h))
+  if (-1 == set_format(cam, &fmt, V4L2_PIX_FMT_RGB444, w, h))
+ return -1;
+
+ /* For reference:
+ V4L2_PIX_FMT_RGB24 : 3 bytes == 1 dst pixel
+ V4L2_PIX_FMT_RGB565: 2 bytes == 1 dst pixel
+ V4L2_PIX_FMT_RGB444: 2 bytes == 1 dst pixel
+ V4L2_PIX_FMT_YUYV  : 4 bytes == 2 dst pixels
+ */
+
+ switch (fmt.fmt.pix.pixelformat) {
+  case V4L2_PIX_FMT_RGB24: /* printf("V4L2_PIX_FMT_RGB24\n"); */
+ bpp = 3;
+ break;
+  case V4L2_PIX_FMT_RGB565: /* printf("V4L2_PIX_FMT_RGB565\n"); */
+ bpp = 2;
+ break;
+  case V4L2_PIX_FMT_RGB444: /* printf("V4L2_PIX_FMT_RGB444\n"); */
+ bpp = 2;
+ break;
+  case V4L2_PIX_FMT_YUYV: /* printf("V4L2_PIX_FMT_YUYV\n"); */
+ bpp = 4;
+ break;
+ }
+
+ /* Buggy driver paranoia >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> */
+ min = fmt.fmt.pix.width * bpp;
+ if (fmt.fmt.pix.bytesperline < min) fmt.fmt.pix.bytesperline = min;
+ min = fmt.fmt.pix.bytesperline * fmt.fmt.pix.height;
+ if (fmt.fmt.pix.sizeimage < min) fmt.fmt.pix.sizeimage = min;
+ /* <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<< */
+
+ if (0 > init_mmap(cam)) return -1;
+ if (0 > queue_buffers(cam)) return -1;
+
+ /* cache returned dims (make fmt a global?) */
+ cam->bmWidth = fmt.fmt.pix.width;
+ cam->bmHeight = fmt.fmt.pix.height;
+ cam->sqPixels = cam->bmWidth * cam->bmHeight;
+ cam->sqBufferBytes = cam->sqPixels * 4; /* Bytes to tx to Squeak (always RGB32) */
+
+ return 0;
+}
+
+
+static int
+close_device (camPtr cam)
+{
+ if (-1 == vd_close (cam->fileDesc)) return -1;
+ cam->fileDesc = -1;
+ return 0;
+}
+
+
+static int
+open_device (camPtr cam)
+{
+ char deviceName[12];
+ struct stat st;
+
+ strcpy(deviceName, videoDevName0);
+ deviceName[10] = cam->devNum + '0';
+
+ if (-1 == stat (deviceName, &st)) return -1;
+ if (!S_ISCHR (st.st_mode)) return -1;
+
+ cam->fileDesc = vd_open (deviceName, O_RDWR /* required */ | O_NONBLOCK, 0);
+
+ if (camIsClosed(cam)) return -1;
+
+ return 0;
+}
+
+
+int
+InitCamera(camPtr cam, int w, int h)
+{
+    cam->read_buf.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
+    cam->read_buf.memory = V4L2_MEMORY_MMAP;
+ cam->ioMethod = IO_METHOD_MMAP;
+
+    if (0 > open_device(cam)) return -1;
+
+    if (0 > init_device(cam, w, h)) {
+        close_device(cam);
+        return -1;
+    }
+
+    if (0 > stream_on(cam)) {
+        uninit_device(cam);
+        close_device(cam);
+        return -1;
+    }
+
+    return 0;
+}
+
+
+
+/* ============================================= SCRATCH I/F ==================================================== */
+
+
+sqInt
+CameraGetParam(int camNum, int paramNum)
+{
+ camPtr cam = &camInfo[camNum-1];
+
+ return 0;
+}
+
+/*
+ "Copy a camera frame into the given Bitmap. The Bitmap should be for a Form
+ of depth 32 that is the same width and height as the current camera frame.
+ Fail if the camera is not open or if the bitmap is not the right size. If
+ successful, answer the number of frames received from the camera since the
+ last call. If this is zero, then there has been no change."
+
+ ???
+*/
+sqInt
+CameraGetFrame(int camNum, unsigned char* buf, int pixelCount)
+{
+ camPtr cam = &camInfo[camNum-1];
+
+ if (camIsClosed(cam)) return false;
+ if (pixelCount != cam->sqPixels) return false;
+ cam->sqBuffer = (void *)buf;
+ if (0 != getFrame(cam)) return 0;
+ return 1;
+}
+
+
+sqInt
+CameraExtent(int camNum)
+{
+ camPtr cam = &camInfo[camNum-1];
+
+ if (camIsClosed(cam)) return 0;
+ return (cam->bmWidth << 16) + cam->bmHeight;
+}
+
+
+char*
+CameraName(int camNum)
+{
+ camPtr cam = &camInfo[camNum-1];
+
+ if (camIsClosed(cam)) return "camera not open";
+ return "default camera";
+}
+
+
+void
+CameraClose(int camNum)
+{
+ camPtr cam = &camInfo[camNum-1];
+
+ if (camIsClosed(cam)) return;
+ stream_off(cam);
+ uninit_device(cam);
+ close_device(cam);
+}
+
+
+sqInt
+CameraOpen(int camNum, int frameWidth, int frameHeight)
+{
+ camPtr cam = &camInfo[camNum-1];
+
+ if (camIsOpen(cam)) return false;
+ if (0 != InitCamera(cam, frameWidth, frameHeight)) return false;
+ return true;
+}
+