blender/source/gameengine/VideoTexture/ImageBase.h
Benoit Bolsee 37b9c9fe4d VideoTexture: improvements to image data access API.
- Use BGL buffer instead of string for image data.
- Add buffer interface to image source.
- Allow customization of pixel format.
- Add valid property to check if the image data is available.

The image property of all Image source objects will now
return a BGL 'buffer' object. Previously it was returning
a string, which was not working at all with Python 3.1.
The BGL buffer type allows sequence access to bytes and
is directly usable in BGL OpenGL wrapper functions.
The buffer is formated as a 1 dimensional array of bytes
with 4 bytes per pixel in RGBA order.

BGL buffers will also be accepted in the ImageBuff load()
and plot() functions.

It is possible to customize the pixel format by using
the VideoTexture.imageToArray(image, mode) function:
the first argument is a Image source object, the second
optional argument is a format string using the R, G, B,
A, 0 and 1 characters. For example "BGR" means that each
pixel will be 3 bytes, corresponding to the Blue, Green
and Red channel in that order. Use 0 for a fixed hex 00
value, 1 for hex FF. The default mode is "RGBA".

All Image source objects now support the buffer interface
which allows to create memoryview objects for direct access
to the image internal buffer without memory copy. The buffer
format is one dimensional array of bytes with 4 bytes per
pixel in RGBA order. The buffer is writable, which allows
custom modifications of the image data.

v = memoryview(source)

A bug in the Python 3.1 buffer API will cause a crash if
the memoryview object cannot be created. Therefore, you
must always check first that an image data is available
before creating a memoryview object. Use the new valid
attribute for that:

if source.valid:
    v = memoryview(source)
    ...	

Note: the BGL buffer object itself does not yet support
the buffer interface.

Note: the valid attribute makes sense only if you use
image source in conjunction with texture object like this:

# refresh texture but keep image data in memory
texture.refresh(False)
if texture.source.valid:
    v = memoryview(texture.source)
    # process image
    ...
    # invalidate image for next texture refresh
    texture.source.refresh()

Limitation: While memoryview objects exist, the image cannot be
resized. Resizing occurs with ImageViewport objects when the
viewport size is changed or with ImageFFmpeg when a new image
is reloaded for example. Any attempt to resize will cause a
runtime error. Delete the memoryview objects is you want to
resize an image source object.
2010-02-21 22:20:00 +00:00

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C++

/* $Id$
-----------------------------------------------------------------------------
This source file is part of blendTex library
Copyright (c) 2007 The Zdeno Ash Miklas
This program is free software; you can redistribute it and/or modify it under
the terms of the GNU Lesser General Public License as published by the Free Software
Foundation; either version 2 of the License, or (at your option) any later
version.
This program is distributed in the hope that it will be useful, but WITHOUT
ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public License along with
this program; if not, write to the Free Software Foundation, Inc., 59 Temple
Place - Suite 330, Boston, MA 02111-1307, USA, or go to
http://www.gnu.org/copyleft/lesser.txt.
-----------------------------------------------------------------------------
*/
#if !defined IMAGEBASE_H
#define IMAGEBASE_H
#include "Common.h"
#include <vector>
#include <PyObjectPlus.h>
#include "PyTypeList.h"
#include "FilterBase.h"
// forward declarations
struct PyImage;
class ImageSource;
/// type for list of image sources
typedef std::vector<ImageSource*> ImageSourceList;
/// base class for image filters
class ImageBase
{
public:
/// constructor
ImageBase (bool staticSrc = false);
/// destructor
virtual ~ImageBase (void);
/// release contained objects, if returns true, object should be deleted
virtual bool release (void);
/// is an image available
bool isImageAvailable(void)
{ return m_avail; }
/// get image
unsigned int * getImage (unsigned int texId = 0, double timestamp=-1.0);
/// get image size
short * getSize (void) { return m_size; }
/// get image buffer size
unsigned long getBuffSize (void)
{ return m_size[0] * m_size[1] * sizeof(unsigned int); }
/// refresh image - invalidate its current content
virtual void refresh (void);
/// get scale
bool getScale (void) { return m_scale; }
/// set scale
void setScale (bool scale) { m_scale = scale; m_scaleChange = true; }
/// get vertical flip
bool getFlip (void) { return m_flip; }
/// set vertical flip
void setFlip (bool flip) { m_flip = flip; }
/// get source object
PyImage * getSource (const char * id);
/// set source object, return true, if source was set
bool setSource (const char * id, PyImage * source);
/// get pixel filter
PyFilter * getFilter (void) { return m_pyfilter; }
/// set pixel filter
void setFilter (PyFilter * filt);
/// calculate size (nearest power of 2)
static short calcSize (short size);
/// number of buffer pointing to m_image, public because not handled by this class
int m_exports;
protected:
/// image buffer
unsigned int * m_image;
/// image buffer size
unsigned int m_imgSize;
/// image size
short m_size[2];
/// image is available
bool m_avail;
/// scale image to power 2 sizes
bool m_scale;
/// scale was changed
bool m_scaleChange;
/// flip image vertically
bool m_flip;
/// source image list
ImageSourceList m_sources;
/// flag for disabling addition and deletion of sources
bool m_staticSources;
/// pixel filter
PyFilter * m_pyfilter;
/// initialize image data
void init (short width, short height);
/// find source
ImageSourceList::iterator findSource (const char * id);
/// create new source
virtual ImageSource * newSource (const char * id) { return NULL; }
/// check source sizes
bool checkSourceSizes (void);
/// calculate image from sources and set its availability
virtual void calcImage (unsigned int texId, double ts) {}
/// perform loop detection
bool loopDetect (ImageBase * img);
/// template for image conversion
template<class FLT, class SRC> void convImage (FLT & filter, SRC srcBuff,
short * srcSize)
{
// destination buffer
unsigned int * dstBuff = m_image;
// pixel size from filter
unsigned int pixSize = filter.firstPixelSize();
// if no scaling is needed
if (srcSize[0] == m_size[0] && srcSize[1] == m_size[1])
// if flipping isn't required
if (!m_flip)
// copy bitmap
for (short y = 0; y < m_size[1]; ++y)
for (short x = 0; x < m_size[0]; ++x, ++dstBuff, srcBuff += pixSize)
// copy pixel
*dstBuff = filter.convert(srcBuff, x, y, srcSize, pixSize);
// otherwise flip image top to bottom
else
{
// go to last row of image
srcBuff += srcSize[0] * (srcSize[1] - 1) * pixSize;
// copy bitmap
for (short y = m_size[1] - 1; y >= 0; --y, srcBuff -= 2 * srcSize[0] * pixSize)
for (short x = 0; x < m_size[0]; ++x, ++dstBuff, srcBuff += pixSize)
// copy pixel
*dstBuff = filter.convert(srcBuff, x, y, srcSize, pixSize);
}
// else scale picture (nearest neighbour)
else
{
// interpolation accumulator
int accHeight = srcSize[1] >> 1;
// if flipping is required
if (m_flip)
// go to last row of image
srcBuff += srcSize[0] * (srcSize[1] - 1) * pixSize;
// process image rows
for (int y = 0; y < srcSize[1]; ++y)
{
// increase height accum
accHeight += m_size[1];
// if pixel row has to be drawn
if (accHeight >= srcSize[1])
{
// decrease accum
accHeight -= srcSize[1];
// width accum
int accWidth = srcSize[0] >> 1;
// process row
for (int x = 0; x < srcSize[0]; ++x)
{
// increase width accum
accWidth += m_size[0];
// if pixel has to be drawn
if (accWidth >= srcSize[0])
{
// decrease accum
accWidth -= srcSize[0];
// convert pixel
*dstBuff = filter.convert(srcBuff, x, m_flip ? srcSize[1] - y - 1 : y,
srcSize, pixSize);
// next pixel
++dstBuff;
}
// shift source pointer
srcBuff += pixSize;
}
}
// if pixel row will not be drawn
else
// move source pointer to next row
srcBuff += pixSize * srcSize[0];
// if y flipping is required
if (m_flip)
// go to previous row of image
srcBuff -= 2 * pixSize * srcSize[0];
}
}
}
// template for specific filter preprocessing
template <class F, class SRC> void filterImage (F & filt, SRC srcBuff, short * srcSize)
{
// find first filter in chain
FilterBase * firstFilter = NULL;
if (m_pyfilter != NULL) firstFilter = m_pyfilter->m_filter->findFirst();
// if first filter is available
if (firstFilter != NULL)
{
// python wrapper for filter
PyFilter pyFilt;
pyFilt.m_filter = &filt;
// set specified filter as first in chain
firstFilter->setPrevious(&pyFilt, false);
// convert video image
convImage(*(m_pyfilter->m_filter), srcBuff, srcSize);
// delete added filter
firstFilter->setPrevious(NULL, false);
}
// otherwise use given filter for conversion
else convImage(filt, srcBuff, srcSize);
// source was processed
m_avail = true;
}
};
// python structure for image filter
struct PyImage
{
PyObject_HEAD
// source object
ImageBase * m_image;
};
// size of id
const int SourceIdSize = 32;
/// class for source of image
class ImageSource
{
public:
/// constructor
ImageSource (const char * id);
/// destructor
virtual ~ImageSource (void);
/// get id
const char * getId (void) { return m_id; }
/// compare id to argument
bool is (const char * id);
/// get source object
PyImage * getSource (void) { return m_source; }
/// set source object
void setSource (PyImage * source);
/// get image from source
unsigned int * getImage (double ts=-1.0);
/// get buffered image
unsigned int * getImageBuf (void) { return m_image; }
/// refresh source
void refresh (void);
/// get image size
short * getSize (void)
{
static short defSize [] = {0, 0};
return m_source != NULL ? m_source->m_image->getSize() : defSize;
}
protected:
/// id of source
char m_id [SourceIdSize];
/// pointer to source structure
PyImage * m_source;
/// buffered image from source
unsigned int * m_image;
private:
/// default constructor is forbidden
ImageSource (void) {}
};
// list of python image types
extern PyTypeList pyImageTypes;
// functions for python interface
// object initialization
template <class T> static int Image_init (PyObject * pySelf, PyObject * args, PyObject * kwds)
{
PyImage * self = reinterpret_cast<PyImage*>(pySelf);
// create source object
if (self->m_image != NULL) delete self->m_image;
self->m_image = new T();
// initialization succeded
return 0;
}
// object allocation
PyObject * Image_allocNew (PyTypeObject * type, PyObject * args, PyObject * kwds);
// object deallocation
void Image_dealloc (PyImage * self);
// get image data
PyObject * Image_getImage (PyImage * self, char * mode);
// get image size
PyObject * Image_getSize (PyImage * self, void * closure);
// refresh image - invalidate current content
PyObject * Image_refresh (PyImage * self);
// get scale
PyObject * Image_getScale (PyImage * self, void * closure);
// set scale
int Image_setScale (PyImage * self, PyObject * value, void * closure);
// get flip
PyObject * Image_getFlip (PyImage * self, void * closure);
// set flip
int Image_setFlip (PyImage * self, PyObject * value, void * closure);
// get filter source object
PyObject * Image_getSource (PyImage * self, PyObject * args);
// set filter source object
PyObject * Image_setSource (PyImage * self, PyObject * args);
// get pixel filter object
PyObject * Image_getFilter (PyImage * self, void * closure);
// set pixel filter object
int Image_setFilter (PyImage * self, PyObject * value, void * closure);
// check if a buffer can be extracted
PyObject * Image_valid(PyImage * self, void * closure);
// for buffer access to PyImage objects
extern PyBufferProcs imageBufferProcs;
#endif