ImageViewport.cpp

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/*
-----------------------------------------------------------------------------
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_Size(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_Size(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 */
};