Ah, thank you!
The problem was I read the way T[].sizeof behaves on static arrays,
thinking I was reading the section on dynamic array properties.
On 25/04/10 21:52, Daniel Murphy wrote:
It should work if you treat the dynamic array like a pointer and a length.
eg:
glBufferData(GL_ARRAY_BUFFER, (vertices[0]).sizeof * vertices.length,
vertices.ptr, GL_STATIC_DRAW);
It's probably because (type).sizeof gives the number of bytes to hold the
type.
For dynamic arrays, this is the size of the (length, pointer) pair and not
the array itself.
float.sizeof // gives 4
int.sizeof // gives 4
int[].sizeof // gives 8
int[3].sizeof // gives 12
class C { int[100] d; };
C.sizeof // gives the size of the reference, not the instance.
I haven't checked the sizes, but it generally follows something like that.
"Bernard Helyer"<b.hel...@gmail.com> wrote in message
news:hr0veq$226...@digitalmars.com...
I was having a problem interfacing with OpenGL from D, as demonstrated by
this program, written once in D, and again in C:
http://gist.github.com/378273
Now the 'gist' of it is, doing things like this (D):
glBufferData(GL_ARRAY_BUFFER, vertices.sizeof,
vertices.ptr, GL_STATIC_DRAW);
glVertexPointer(2, GL_FLOAT, GLfloat.sizeof * 2, cast(void*)0);
With this data (D):
const GLfloat[] vertices = [-1.0f, -1.0f, 1.0f, -
1.0f, -1.0f, 1.0f, 1.0f, 1.0f];
and the same data in C:
const GLfloat vertices[] = {-1.0f, -1.0f, 1.0f,
-1.0f, -1.0f, 1.0f, 1.0f, 1.0f};
I was getting nothing but a blank screen. I'm sure you smart folks know
what comes next.
GLfloat[] vertices = {1.0f, 1.0f}; // vertices is a dynamic array.
GLfloat[2] vertices = {1.0f, 1.0f}; // vertices is a static array.
The second version enables the program to work as the C one does.
My question is, why doesn't passing the `GLfloat[] vertex ...` declaration
work? I've looked through the docs, and can't see anything too obvious.
Thanks.
