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Use the gfx vertex macro via a workaround

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This commit is contained in:
Joonas Javanainen 2019-07-17 11:19:07 +03:00
parent 3369abd429
commit 50f4a2c975
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1 changed files with 41 additions and 41 deletions
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82
src/render/draw_data.rs
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@ -224,49 +224,49 @@ use glium::implement_vertex;
implement_vertex!(DrawVert, pos, uv, col);
#[cfg(feature = "gfx")]
unsafe impl gfx::traits::Pod for DrawVert {}
#[cfg(feature = "gfx")]
impl gfx::pso::buffer::Structure<gfx::format::Format> for DrawVert {
fn query(name: &str) -> Option<gfx::pso::buffer::Element<gfx::format::Format>> {
// array query hack from gfx_impl_struct_meta macro
use gfx::format::Formatted;
use gfx::pso::buffer::{ElemOffset, Element};
use std::mem::{size_of, transmute};
// using "1" here as a simple non-zero pointer addres
let tmp: &DrawVert = unsafe { transmute(1usize) };
let base = tmp as *const _ as usize;
//HACK: special treatment of array queries
let (sub_name, big_offset) = {
let mut split = name.split(|c| c == '[' || c == ']');
let _ = split.next().unwrap();
match split.next() {
Some(s) => {
let array_id: ElemOffset = s.parse().unwrap();
let sub_name = match split.next() {
Some(s) if s.starts_with('.') => &s[1..],
_ => name,
};
(sub_name, array_id * (size_of::<DrawVert>() as ElemOffset))
}
None => (name, 0),
}
};
match sub_name {
"pos" => Some(Element {
format: <[f32; 2] as Formatted>::get_format(),
offset: ((&tmp.pos as *const _ as usize) - base) as ElemOffset + big_offset,
}),
"uv" => Some(Element {
format: <[f32; 2] as Formatted>::get_format(),
offset: ((&tmp.uv as *const _ as usize) - base) as ElemOffset + big_offset,
}),
"col" => Some(Element {
format: <[gfx::format::U8Norm; 4] as Formatted>::get_format(),
offset: ((&tmp.col as *const _ as usize) - base) as ElemOffset + big_offset,
}),
_ => None,
mod gfx_support {
use gfx::*;
use super::DrawVert;
// gfx doesn't provide a macro to implement vertex structure for an existing struct, so we
// create a dummy vertex with the same memory layout using gfx macros, and delegate query(name)
// calls later to the automatically derived implementation
gfx_vertex_struct! {
Dummy {
pos: [f32; 2] = "pos",
uv: [f32; 2] = "uv",
col: [format::U8Norm; 4] = "col",
}
}
unsafe impl gfx::traits::Pod for DrawVert {}
impl gfx::pso::buffer::Structure<gfx::format::Format> for DrawVert {
fn query(name: &str) -> Option<gfx::pso::buffer::Element<gfx::format::Format>> {
// Dummy has the same memory layout, so this should be ok
Dummy::query(name)
}
}
#[test]
fn test_dummy_memory_layout() {
use std::mem;
assert_eq!(
mem::size_of::<DrawVert>(),
mem::size_of::<Dummy>()
);
assert_eq!(
mem::align_of::<DrawVert>(),
mem::align_of::<Dummy>()
);
use memoffset::offset_of;
macro_rules! assert_field_offset {
($l:ident, $r:ident) => {
assert_eq!(offset_of!(DrawVert, $l), offset_of!(Dummy, $r));
};
};
assert_field_offset!(pos, pos);
assert_field_offset!(uv, uv);
assert_field_offset!(col, col);
}
}
#[test]