Enlightenment CVS committal
Author : barbieri
Project : e17
Module : proto/python-efl
Dir : e17/proto/python-efl/python-evas/evas
Modified Files:
evas.c_evas_object_image.pxi
Log Message:
Implement data_get() using Python Buffer API, related methods and add comments.
===================================================================
RCS file:
/cvs/e/e17/proto/python-efl/python-evas/evas/evas.c_evas_object_image.pxi,v
retrieving revision 1.10
retrieving revision 1.11
diff -u -3 -r1.10 -r1.11
--- evas.c_evas_object_image.pxi 8 Oct 2007 15:09:01 -0000 1.10
+++ evas.c_evas_object_image.pxi 21 Oct 2007 00:51:02 -0000 1.11
@@ -1,8 +1,95 @@
# This file is included verbatim by c_evas.pyx
+cdef int _data_size_get(Evas_Object *obj):
+ cdef int stride, h, bpp, cspace, have_alpha
+ stride = evas_object_image_stride_get(obj)
+ evas_object_image_size_get(obj, NULL, &h)
+ cspace = evas_object_image_colorspace_get(obj)
+ have_alpha = evas_object_image_alpha_get(obj)
+ if cspace == EVAS_COLORSPACE_ARGB8888:
+ bpp = 4
+ elif cspace == EVAS_COLORSPACE_RGB565_A5P:
+ if have_alpha == 0:
+ bpp = 2
+ else:
+ bpp = 3
+ else:
+ return 0 # XXX not supported.
+
+ return stride * h * bpp
+
+
cdef public class Image(Object) [object PyEvasImage, type PyEvasImage_Type]:
"""Image from file or buffer.
+ Introduction
+ ============
+
+ Image will consider the object's L{geometry<Object.geometry_set()>} as
+ the area to paint with tiles as described by L{fill_set()} and the real
+ pixels (image data) will be stored as described by
+ L{image_size<image_size_set()>}. This can be tricky to understand at
+ first, but gives flexibility to do everything.
+
+ If an image is loaded from file, it will have
+ L{image_size<image_size_set()>} set to its original size, unless some
+ other size was set with L{load_size_set()}, L{load_dpi_set()} or
+ L{load_scale_down_set()}.
+
+ Pixels will be scaled to match size specified by L{fill_set()}
+ using either sampled or smooth methods, these can be specified with
+ L{smooth_scale_set()}. The scale will consider borders as specified by
+ L{border_set()} and L{border_center_fill_set()}, while the former specify
+ the border dimensions (top and bottom will scale horizontally, while
+ right and left will do vertically, corners are kept unscaled), the latter
+ says whenever the center of the image will be used (useful to create
+ frames).
+
+ Contents will be tiled using L{fill_set()} information in order to paint
+ L{geometry<Object.geometry_set()>}, so if you want an image to be drawn
+ just once, you should match every L{geometry_set(x, y, w, h)} by a call
+ to L{fill_set(0, 0, w, h)}. L{FilledImage} does that for you.
+
+ Pixel data and buffer API
+ =========================
+
+ Images implement the Python Buffer API, so it's possible to use it
+ where buffers are expected (ie: file.write()). Available data will
+ depend on L{alpha<alpha_set()>}, L{colorspace<colorspace_set()>} and
+ L{image_size<image_size_set()>}, lines should be considered multiple
+ of L{stride<stride_get()>}, with the following considerations about
+ colorspace:
+ - B{EVAS_COLORSPACE_ARGB8888:} This pixel format is a linear block of
+ pixels, starting at the top-left row by row until the bottom right of
+ the image or pixel region. All pixels are 32-bit unsigned int's with
+ the high-byte being alpha and the low byte being blue in the format
+ ARGB. Alpha may or may not be used by evas depending on the alpha flag
+ of the image, but if not used, should be set to 0xff anyway.
+ This colorspace uses premultiplied alpha. That means that R, G and B
+ cannot exceed A in value. The conversion from non-premultiplied
+ colorspace is::
+ R = (r * a) / 255; G = (g * a) / 255; B = (b * a) / 255;
+ So 50% transparent blue will be: 0x80000080. This will not be "dark" -
+ just 50% transparent. Values are 0 == black, 255 == solid or full
+ red, green or blue.
+ - B{EVAS_COLORSPACE_RGB565_A5P:} In the process of being implemented in
+ 1 engine only. This may change. This is a pointer to image data for
+ 16-bit half-word pixel data in 16bpp RGB 565 format (5 bits red,
+ 6 bits green, 5 bits blue), with the high-byte containing red and the
+ low byte containing blue, per pixel. This data is packed row by row
+ from the top-left to the bottom right. If the image has an alpha
+ channel enabled there will be an extra alpha plane B{after} the color
+ pixel plane. If not, then this data will not exist and should not be
+ accessed in any way. This plane is a set of pixels with 1 byte per
+ pixel defining the alpha values of all pixels in the image from
+ the top-left to the bottom right of the image, row by row. Even though
+ the values of the alpha pixels can be 0 to 255, only values 0 through
+ to 31 are used, 31 being solid and 0 being transparent.
+ RGB values can be 0 to 31 for red and blue and 0 to 63 for green, with 0
+ being black and 31 or 63 being full red, green or blue respectively.
+ This colorspace is also pre-multiplied like EVAS_COLORSPACE_ARGB8888
so::
+ R = (r * a) / 32; G = (g * a) / 32; B = (b * a) / 32;
+
@note: if an image is resized it will B{tile} it's contents respecting
geometry set by L{fill_set()}, so if you want the contents to be
B{scaled} you need to call L{fill_set()} with C{x=0, y=0, w=new_width,
@@ -14,8 +101,8 @@
load_dpi_set, load_dpi_get, load_dpi,
load_scale_down_set, load_scale_down_get, load_scale_down
@group Often unused: alpha_set, alpha_get, alpha, colorspace_set,
- colorspace_set, colorspace, pixels_dirty_set, pixels_dirty_get,
- pixels_dirty
+ colorspace_get, colorspace, pixels_dirty_set, pixels_dirty_get,
+ pixels_dirty, image_data_set, image_data_update_add
"""
def __init__(self, Canvas canvas not None, **kargs):
Object.__init__(self, canvas)
@@ -180,6 +267,13 @@
larger, then the image will be treated as if it were in the upper
left hand corner of a larger image that is otherwise transparent.
+ This method will force pixels to be allocated if they weren't, so
+ you should use this before accessing the image as a buffer in order
+ to allocate the pixels.
+
+ This method will recalculate L{stride} (L{stride_get()}) based on
+ width and the colorspace.
+
@parm: B{w}
@parm: B{h}
"""
@@ -192,6 +286,30 @@
def __set__(self, spec):
self.image_size_set(*spec)
+ def stride_get(self):
+ """Get the row stride (in pixels) being used to draw this image.
+
+ While image have logical dimension of width and height set by
+ L{image_size_set()}, the line can be a bit larger than width to
+ improve memory alignment.
+
+ The amount of bytes will change based on colorspace, while using
+ ARGB8888 it will be multiple of 4 bytes, with colors being laid
+ out interleaved, RGB565_A5P will have the first part being RGB
+ data using stride in multiple of 2 bytes and after that an
+ alpha plane with data using stride in multiple of 1 byte.
+
+ @note: This value can change after L{image_size_set()}.
+ @note: Unit is pixels, not bytes.
+
+ @rtype: int
+ """
+ return evas_object_image_stride_get(self.obj)
+
+ property stride:
+ def __get__(self):
+ return self.stride_get()
+
def alpha_get(self):
"@rtype: bool"
return bool(evas_object_image_alpha_get(self.obj))
@@ -342,6 +460,81 @@
else:
f = NULL
evas_object_image_save(self.obj, filename, key, flags)
+
+ def __getsegcount__(self, int *p_len):
+ if p_len == NULL:
+ return 1
+
+ p_len[0] = _data_size_get(self.obj)
+ return 1
+
+ def __getreadbuffer__(self, int segment, void **ptr):
+ ptr[0] = evas_object_image_data_get(self.obj, 0)
+ if ptr[0] == NULL:
+ raise SystemError("image has no allocated buffer.")
+ # XXX: keep Evas pixels_checked_out counter to 0 and allow
+ # XXX: image to reload and unload its data.
+ # XXX: may cause problems if buffer is used after these
+ # XXX: functions are called, but buffers aren't expected to
+ # XXX: live much.
+ evas_object_image_data_set(self.obj, ptr[0])
+ return _data_size_get(self.obj)
+
+ def __getwritebuffer__(self, int segment, void **ptr):
+ ptr[0] = evas_object_image_data_get(self.obj, 1)
+ if ptr[0] == NULL:
+ raise SystemError("image has no allocated buffer.")
+ # XXX: keep Evas pixels_checked_out counter to 0 and allow
+ # XXX: image to reload and unload its data.
+ # XXX: may cause problems if buffer is used after these
+ # XXX: functions are called, but buffers aren't expected to
+ # XXX: live much.
+ evas_object_image_data_set(self.obj, ptr[0])
+ return _data_size_get(self.obj)
+
+ def __getcharbuffer__(self, int segment, char **ptr):
+ ptr[0] = <char *>evas_object_image_data_get(self.obj, 0)
+ if ptr[0] == NULL:
+ raise SystemError("image has no allocated buffer.")
+ # XXX: keep Evas pixels_checked_out counter to 0 and allow
+ # XXX: image to reload and unload its data.
+ # XXX: may cause problems if buffer is used after these
+ # XXX: functions are called, but buffers aren't expected to
+ # XXX: live much.
+ evas_object_image_data_set(self.obj, ptr[0])
+ return _data_size_get(self.obj)
+
+ def image_data_set(self, buf):
+ """Sets the raw image data.
+
+ The given buffer will be B{copied}, so it's safe to give it a
+ temporary object.
+
+ @note: that the raw data must be of the same size and colorspace
+ of the image. If data is None the current image data will be freed.
+ """
+ cdef void *p_data
+ cdef Py_ssize_t size, expected_size
+
+ if buf is None:
+ evas_object_image_data_set(self.obj, NULL)
+ return
+
+ python.PyObject_AsReadBuffer(buf, &p_data, &size)
+ if p_data != NULL:
+ expected_size = _data_size_get(self.obj)
+ if size < expected_size:
+ raise ValueError(("buffer size (%d) is smalled than expected "
+ "(%d)!") % (size, expected_size))
+ evas_object_image_data_set(self.obj, p_data)
+
+ def image_data_update_add(self, x, y, w, h):
+ """Mark a sub-region of the image to be redrawn.
+
+ This function schedules a particular rectangular region
+ to be updated (redrawn) at the next render.
+ """
+ evas_object_image_data_update_add(self.obj, x, y, w, h)
cdef extern from "Python.h":
-------------------------------------------------------------------------
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