arglDrawMode |
int arglDrawMode;
The value of this variable determines the method by which
arglDispImage transfers pixels of an image to the display. Setting this
variable to a value of AR_DRAW_BY_GL_DRAW_PIXELS specifies the use of OpenGL
DrawPixels to do the transfer. Setting this variable to a value of
AR_DRAW_BY_TEXTURE_MAPPING specifies the use of OpenGL TexImage2D to do the
transfer. The DrawPixels method is guaranteed to be available on all
implementations, but arglDispImage does not correct the image
for camera lens distortion under this method. In contrast, TexImage2D is only
available on some implementations, but allows arglDispImage() to apply a correction
for camera lens distortion, and additionally offers greater potential for
accelerated drawing on some implementations.
The initial value is defined to the value of the symbolic constan DEFAULT_DRAW_MODE
(defined in <AR/config.h>).
arglTexRectangle |
BOOL arglTexRectangle;
On implementations which support the OpenGL extension for rectangular textures (of
non power-of-two size), and when arglDrawMode is set to AR_DRAW_BY_TEXTURE_MAPPING,
the value of this variable determines whether rectangular textures or ordinary
(power-of-two) textures are used by arglDispImage(). A value of TRUE specifies the
use of rectangluar textures. A value of FALSE specifies the use of ordinary textures.
If gsub_lite was not built without support for rectangular textures, changing the
value of this variable will have no effect, and ordinary textures will always be
used. Support for rectangular textures is only available when gsub_lite is built
with AR_OPENGL_TEXTURE_RECTANGLE defined in <AR/config.h> and with either
GL_EXT_texture_rectangle or GL_NV_texture_rectangle defined in <GL/glext.h>
or <GL/gl.h>
arglTexmapMode |
int arglTexmapMode;
When arglDrawMode is set to AR_DRAW_BY_TEXTURE_MAPPING, the value of this variable determines whether full or half-resolution data is transferred to the texture. A value of AR_DRAW_TEXTURE_FULL_IMAGE uses all available pixels in the source image data. A value of AR_DRAW_TEXTURE_HALF_IMAGE discards every second pixel in the source image data, defining a half-width texture which is then drawn stretched horizontally to double its width. The latter method offers some advantages to certain implentations where texture transfer is slow or costly, at the expense of image detail.
© 2003-2004 Philip Lamb (Last Updated 07/02/2004)