blender/source/gameengine/VideoTexture/ImageViewport.cpp
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

349 lines
11 KiB
C++

/* $Id$
-----------------------------------------------------------------------------
This source file is part of VideoTexture 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.
-----------------------------------------------------------------------------
*/
// implementation
#include <PyObjectPlus.h>
#include <structmember.h>
#include "GL/glew.h"
#include "Texture.h"
#include "ImageBase.h"
#include "FilterSource.h"
#include "ImageViewport.h"
// constructor
ImageViewport::ImageViewport (void) : m_alpha(false), m_texInit(false)
{
// get viewport rectangle
glGetIntegerv(GL_VIEWPORT, m_viewport);
// create buffer for viewport image
m_viewportImage = new BYTE [4 * getViewportSize()[0] * getViewportSize()[1]];
// set attributes
setWhole(false);
}
// destructor
ImageViewport::~ImageViewport (void)
{ delete m_viewportImage; }
// use whole viewport to capture image
void ImageViewport::setWhole (bool whole)
{
// set whole
m_whole = whole;
// set capture size to viewport size, if whole,
// otherwise place area in the middle of viewport
for (int idx = 0; idx < 2; ++idx)
{
// capture size
m_capSize[idx] = whole ? short(getViewportSize()[idx])
: calcSize(short(getViewportSize()[idx]));
// position
m_position[idx] = whole ? 0 : ((getViewportSize()[idx] - m_capSize[idx]) >> 1);
}
// init image
init(m_capSize[0], m_capSize[1]);
// set capture position
setPosition();
}
void ImageViewport::setCaptureSize (short * size)
{
m_whole = false;
if (size == NULL)
size = m_capSize;
for (int idx = 0; idx < 2; ++idx)
{
if (size[idx] < 1)
m_capSize[idx] = 1;
else if (size[idx] > getViewportSize()[idx])
m_capSize[idx] = short(getViewportSize()[idx]);
else
m_capSize[idx] = size[idx];
}
init(m_capSize[0], m_capSize[1]);
// set capture position
setPosition();
}
// set position of capture rectangle
void ImageViewport::setPosition (GLint * pos)
{
// if new position is not provided, use existing position
if (pos == NULL) pos = m_position;
// save position
for (int idx = 0; idx < 2; ++idx)
m_position[idx] = pos[idx] < 0 ? 0 : pos[idx] >= getViewportSize()[idx]
- m_capSize[idx] ? getViewportSize()[idx] - m_capSize[idx] : pos[idx];
// recalc up left corner
for (int idx = 0; idx < 2; ++idx)
m_upLeft[idx] = m_position[idx] + m_viewport[idx];
}
// capture image from viewport
void ImageViewport::calcImage (unsigned int texId, double ts)
{
// if scale was changed
if (m_scaleChange)
// reset image
init(m_capSize[0], m_capSize[1]);
// if texture wasn't initialized
if (!m_texInit)
{
// initialize it
loadTexture(texId, m_image, m_size);
m_texInit = true;
}
// if texture can be directly created
if (texId != 0 && m_pyfilter == NULL && m_capSize[0] == calcSize(m_capSize[0])
&& m_capSize[1] == calcSize(m_capSize[1]) && !m_flip)
{
// just copy current viewport to texture
glBindTexture(GL_TEXTURE_2D, texId);
glCopyTexSubImage2D(GL_TEXTURE_2D, 0, 0, 0, m_upLeft[0], m_upLeft[1], (GLsizei)m_capSize[0], (GLsizei)m_capSize[1]);
// image is not available
m_avail = false;
}
// otherwise copy viewport to buffer, if image is not available
else if (!m_avail)
{
// get frame buffer data
if (m_alpha)
{
glReadPixels(m_upLeft[0], m_upLeft[1], (GLsizei)m_capSize[0], (GLsizei)m_capSize[1], GL_RGBA,
GL_UNSIGNED_BYTE, m_viewportImage);
// filter loaded data
FilterRGBA32 filt;
filterImage(filt, m_viewportImage, m_capSize);
}
else
{
glReadPixels(m_upLeft[0], m_upLeft[1], (GLsizei)m_capSize[0], (GLsizei)m_capSize[1], GL_RGB,
GL_UNSIGNED_BYTE, m_viewportImage);
// filter loaded data
FilterRGB24 filt;
filterImage(filt, m_viewportImage, m_capSize);
}
}
}
// cast Image pointer to ImageViewport
inline ImageViewport * getImageViewport (PyImage * self)
{ return static_cast<ImageViewport*>(self->m_image); }
// python methods
// get whole
PyObject * ImageViewport_getWhole (PyImage * self, void * closure)
{
if (self->m_image != NULL && getImageViewport(self)->getWhole()) Py_RETURN_TRUE;
else Py_RETURN_FALSE;
}
// set whole
int ImageViewport_setWhole (PyImage * self, PyObject * value, void * closure)
{
// check parameter, report failure
if (value == NULL || !PyBool_Check(value))
{
PyErr_SetString(PyExc_TypeError, "The value must be a bool");
return -1;
}
try
{
// set whole, can throw in case of resize and buffer exports
if (self->m_image != NULL) getImageViewport(self)->setWhole(value == Py_True);
}
catch (Exception & exp)
{
exp.report();
return -1;
}
// success
return 0;
}
// get alpha
PyObject * ImageViewport_getAlpha (PyImage * self, void * closure)
{
if (self->m_image != NULL && getImageViewport(self)->getAlpha()) Py_RETURN_TRUE;
else Py_RETURN_FALSE;
}
// set whole
int ImageViewport_setAlpha (PyImage * self, PyObject * value, void * closure)
{
// check parameter, report failure
if (value == NULL || !PyBool_Check(value))
{
PyErr_SetString(PyExc_TypeError, "The value must be a bool");
return -1;
}
// set alpha
if (self->m_image != NULL) getImageViewport(self)->setAlpha(value == Py_True);
// success
return 0;
}
// get position
static PyObject * ImageViewport_getPosition (PyImage * self, void * closure)
{
return Py_BuildValue("(ii)", getImageViewport(self)->getPosition()[0],
getImageViewport(self)->getPosition()[1]);
}
// set position
static int ImageViewport_setPosition (PyImage * self, PyObject * value, void * closure)
{
// check validity of parameter
if (value == NULL || !PySequence_Check(value) || PySequence_Length(value) != 2
|| !PyLong_Check(PySequence_Fast_GET_ITEM(value, 0))
|| !PyLong_Check(PySequence_Fast_GET_ITEM(value, 1)))
{
PyErr_SetString(PyExc_TypeError, "The value must be a sequence of 2 ints");
return -1;
}
// set position
GLint pos [] = {
GLint(PyLong_AsSsize_t(PySequence_Fast_GET_ITEM(value, 0))),
GLint(PyLong_AsSsize_t(PySequence_Fast_GET_ITEM(value, 1)))
};
getImageViewport(self)->setPosition(pos);
// success
return 0;
}
// get capture size
PyObject * ImageViewport_getCaptureSize (PyImage * self, void * closure)
{
return Py_BuildValue("(ii)", getImageViewport(self)->getCaptureSize()[0],
getImageViewport(self)->getCaptureSize()[1]);
}
// set capture size
int ImageViewport_setCaptureSize (PyImage * self, PyObject * value, void * closure)
{
// check validity of parameter
if (value == NULL || !PySequence_Check(value) || PySequence_Length(value) != 2
|| !PyLong_Check(PySequence_Fast_GET_ITEM(value, 0))
|| !PyLong_Check(PySequence_Fast_GET_ITEM(value, 1)))
{
PyErr_SetString(PyExc_TypeError, "The value must be a sequence of 2 ints");
return -1;
}
// set capture size
short size [] = {
short(PyLong_AsSsize_t(PySequence_Fast_GET_ITEM(value, 0))),
short(PyLong_AsSsize_t(PySequence_Fast_GET_ITEM(value, 1)))
};
try
{
// can throw in case of resize and buffer exports
getImageViewport(self)->setCaptureSize(size);
}
catch (Exception & exp)
{
exp.report();
return -1;
}
// success
return 0;
}
// methods structure
static PyMethodDef imageViewportMethods[] =
{ // methods from ImageBase class
{"refresh", (PyCFunction)Image_refresh, METH_NOARGS, "Refresh image - invalidate its current content"},
{NULL}
};
// attributes structure
static PyGetSetDef imageViewportGetSets[] =
{
{(char*)"whole", (getter)ImageViewport_getWhole, (setter)ImageViewport_setWhole, (char*)"use whole viewport to capture", NULL},
{(char*)"position", (getter)ImageViewport_getPosition, (setter)ImageViewport_setPosition, (char*)"upper left corner of captured area", NULL},
{(char*)"capsize", (getter)ImageViewport_getCaptureSize, (setter)ImageViewport_setCaptureSize, (char*)"size of viewport area being captured", NULL},
{(char*)"alpha", (getter)ImageViewport_getAlpha, (setter)ImageViewport_setAlpha, (char*)"use alpha in texture", NULL},
// attributes from ImageBase class
{(char*)"valid", (getter)Image_valid, NULL, (char*)"bool to tell if an image is available", NULL},
{(char*)"image", (getter)Image_getImage, NULL, (char*)"image data", NULL},
{(char*)"size", (getter)Image_getSize, NULL, (char*)"image size", NULL},
{(char*)"scale", (getter)Image_getScale, (setter)Image_setScale, (char*)"fast scale of image (near neighbour)", NULL},
{(char*)"flip", (getter)Image_getFlip, (setter)Image_setFlip, (char*)"flip image vertically", NULL},
{(char*)"filter", (getter)Image_getFilter, (setter)Image_setFilter, (char*)"pixel filter", NULL},
{NULL}
};
// define python type
PyTypeObject ImageViewportType =
{
PyVarObject_HEAD_INIT(NULL, 0)
"VideoTexture.ImageViewport", /*tp_name*/
sizeof(PyImage), /*tp_basicsize*/
0, /*tp_itemsize*/
(destructor)Image_dealloc, /*tp_dealloc*/
0, /*tp_print*/
0, /*tp_getattr*/
0, /*tp_setattr*/
0, /*tp_compare*/
0, /*tp_repr*/
0, /*tp_as_number*/
0, /*tp_as_sequence*/
0, /*tp_as_mapping*/
0, /*tp_hash */
0, /*tp_call*/
0, /*tp_str*/
0, /*tp_getattro*/
0, /*tp_setattro*/
&imageBufferProcs, /*tp_as_buffer*/
Py_TPFLAGS_DEFAULT, /*tp_flags*/
"Image source from viewport", /* tp_doc */
0, /* tp_traverse */
0, /* tp_clear */
0, /* tp_richcompare */
0, /* tp_weaklistoffset */
0, /* tp_iter */
0, /* tp_iternext */
imageViewportMethods, /* tp_methods */
0, /* tp_members */
imageViewportGetSets, /* tp_getset */
0, /* tp_base */
0, /* tp_dict */
0, /* tp_descr_get */
0, /* tp_descr_set */
0, /* tp_dictoffset */
(initproc)Image_init<ImageViewport>, /* tp_init */
0, /* tp_alloc */
Image_allocNew, /* tp_new */
};