GIR Binding of OpenGL Functions

Description

For full details of OpenGL functions or constants, consult http://www.opengl.org or your local man 3 pages.

Details

NOT ALL FUNCTIONS HAVE BEEN BOUND. FIXME! See gl_funcs.r or gl_funcs.c for details.

You'll notice that GIR is not a 100% exact binding of OpenGL. This is due to the fact R is interpreted (so we can do things like detecting types and parameter lengths at runtime), and has a slightly different type structure to the C-style languages that OpenGL was written against (the default numeric type is double-precision floating-point; there are no bytes or shorts; also, no pointers).

Also, R's integers are always signed. Thus unsigned ints, where applicable, have to be represented as reals.

gl*ntv functions (e.g glVertex3fv) are replaced by gl*v functions taking an R vector (e.g glVertexv). The components of the vector can be real (double) or integer (or, in the case of glEdgeFlagv, boolean). Their types, and the length of the vector, determine which underlying gl function is called. Lengths that don't make sense (e.g <2 or >4 for glVertex) will cause errors. In cases where the argument a function takes is interpreted differently based on its type (a number of gl functions consider the largest representable value of an integral argument as 1.0, and the smallest as 0.0 or -1.0), and that type is not native to R, the original function (with the original suffix) is preserved.

Name Changes

glLightfv, glLightiv -> glLightv

glLightModelfv, glLightModeliv -> glLightModelv

glMaterialfv, glMaterialiv -> glMaterialv

glLoadMatrixf, glLoadMatrixd -> glLoadMatrix

glMultMatrixf, glMultMatrixd -> glMultMatrix

glNormal3dfis -> glNormal3v, glNormal3dv, glNormal3fv, glNormal3iv, glNormal3sv

glVertex234dfis -> glVertexv, glVertexdv, glVertexfv, glVertexiv, glVertexsv

glColor34dfubis -> glColorv, glColordv, glColorfv, glColoriv, glColorbv, glColorsv, glColorubv, glColoruiv, glColorusv

glTexCoord1234dfis -> glTexCoordv, glTexCoordsv

glTexEnvfv, glTexEnviv -> glTexEnvv

glTexGendv, glTexGenfv, glTexGeniv -> glTexGenv

glTexParameterfv, glTexParameteriv -> glTexParameterv

glFogfv, glFogiv -> glFogv

anything I've missed -> something hopefully sane

Functionality/Parameter Changes

glGetBooleanv, glGetDoublev, glGetFloatv, glGetIntegerv: Instead of accepting a pointer to an array in which to store their results, they return a vector. Additionally, they take an extra parameter 'len', which is the length of the array that the gl function expects (in booleans, doubles, floats or ints, respectively). If this is incorrect, unpleasant things will happen (heap corruption). In this respect, it's just like in C. :)

glGetTexParameterfiv, glGetTexLevelParameterfiv: In a similar fashion, these now do not accept a pointer, rather returning their results as a vector. They don't need an extra 'len' parameter, though; they're simple enough not to need it.

glGenTextures: Takes one less argument (textures); returns the resulting texture names in a vector of length n.

glDeleteTextures: Takes one less argument (n); instead of requiring n to be specified, the length of the textures vector is used.

All functions that require a packed array of bytes (glTexture*, etc) must be called with a 'raw' vector. girAsRaw is a good way of getting one from arbitrary data.