🚧 checkpoint before adding GPU buffers

Cargo.lock

@@ -190,6 +190,7 @@ dependencies = [
 name = "opengl_rust"
 version = "0.1.0"
 dependencies = [
+ "byteorder 1.3.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "gl 0.14.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "glam 0.8.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "nom 5.1.0 (registry+https://github.com/rust-lang/crates.io-index)",

Cargo.toml

@@ -8,6 +8,8 @@ edition = "2018"
 
 [dependencies]
 
+byteorder = "1.3.2"
+
 gl = "0.14.0"
 glam = "0.8.5"
 

src/bin/pumpkin.rs

@@ -227,6 +227,9 @@ fn main () {
 	let model_data = load_small_file ("pumpking.iqm", 1024 * 1024);
 	let model = Model::from_slice (&model_data [..]);
 	
+	let pumpkin_verts = glezz::VertexBuffer::from_slice (model.get_vertex_slice (0));
+	let pumpkin_indexes = glezz::IndexBuffer::from_slice (model.get_index_slice (0));
+	
 	let sky_data = load_small_file ("sky-sphere.iqm", 1024 * 1024);
 	let sky_model = Model::from_slice (&sky_data [..]);
 	
@@ -312,16 +315,25 @@ fn main () {
 		// right from RAM I can still access. Using a VBO here
 		// might actually make it easier to make it safe.
 		
+		if false {
+			unsafe {
+				point_to_model (&attrs, &model);
+				
+				gl::DrawElements (gl::TRIANGLES, (model.meshes [0].num_triangles * 3) as i32, gl::UNSIGNED_INT, &model.get_index_slice (0) [0] as *const u8 as *const c_void);
+			}
+		}
+		
 		unsafe {
-			point_to_model (&attrs, &model);
-			
-			gl::DrawElements (gl::TRIANGLES, (model.meshes [0].num_triangles * 3) as i32, gl::UNSIGNED_INT, &model.get_index_slice (0) [0] as *const u8 as *const c_void);
+			gl::BindBuffer (gl::ARRAY_BUFFER, 0);
+			gl::BindBuffer (gl::ELEMENT_ARRAY_BUFFER, 0);
 		}
 		
 		if true {
 			glezz::uniform_3fv (unis ["albedo"], &green);
 			
 			unsafe {
+				point_to_model (&attrs, &model);
+				
 				gl::DrawElements (gl::TRIANGLES, (model.meshes [1].num_triangles * 3) as i32, gl::UNSIGNED_INT, &model.get_index_slice (1) [0] as *const u8 as *const c_void);
 			}
 		}

src/glezz.rs

@@ -1,6 +1,14 @@
 // Trivial wrappers around GLESv2 C functions that should be safe
 
+use byteorder::{LittleEndian, ReadBytesExt};
 use glam::{Mat4, Vec3, Vec4};
+use std::collections::*;
+use std::convert::TryInto;
+use std::cmp;
+use std::io::Cursor;
+use std::ffi::c_void;
+
+use crate::iqm;
 
 pub fn clear_color (r: f32, g: f32, b: f32, a: f32) {
 	unsafe {
@@ -60,3 +68,150 @@ pub fn uniform_matrix_4fv (uni: i32, m: &Mat4) {
 		gl::UniformMatrix4fv (uni, 1, FALSE_U8, m as *const Mat4 as *const f32);
 	}
 }
+
+// More abstract stuff
+
+unsafe fn vertex_attrib_pointer (id: Option <u32>, num_coords: i32, slice: &[u8]) {
+	const FALSE_U8: u8 = 0;
+	const FLOAT_SIZE: i32 = 4;
+	
+	if let Some (id) = id {
+		gl::VertexAttribPointer (id, num_coords, gl::FLOAT, FALSE_U8, FLOAT_SIZE * num_coords, &slice [0] as *const u8 as *const c_void);
+	}
+}
+
+pub fn draw_model (
+	attrs: &HashMap <String, Option <u32>>,
+	model: &iqm::Model, 
+	mesh_number: usize
+) {
+	let index_slice: &[u8] = model.get_index_slice (mesh_number);
+	let num_indexes = model.meshes [mesh_number].num_triangles * 3;
+	
+	unsafe {
+		vertex_attrib_pointer (attrs ["pos"], 3, model.get_vertex_slice (0));
+		vertex_attrib_pointer (attrs ["uv"], 2, model.get_vertex_slice (1));
+		vertex_attrib_pointer (attrs ["normal"], 3, model.get_vertex_slice (2));
+		
+		gl::DrawElements (gl::TRIANGLES, (num_indexes) as i32, gl::UNSIGNED_INT, &index_slice [0] as *const u8 as *const c_void);
+	}
+}
+
+pub struct VertexBuffer {
+	id: u32,
+	len: usize,
+}
+
+impl VertexBuffer {
+	pub fn from_slice (slice: &[u8]) -> Self {
+		let id = {
+			let mut id = 0;
+			unsafe {
+				gl::GenBuffers (1, &mut id);
+				gl::BindBuffer (gl::ARRAY_BUFFER, id);
+				
+				gl::BufferData (gl::ARRAY_BUFFER, slice.len ().try_into ().unwrap (), &slice [0] as *const u8 as *const c_void, gl::STATIC_DRAW);
+			}
+			assert! (id != 0);
+			id
+		};
+		
+		Self {
+			id,
+			len: slice.len (),
+		}
+	}
+	
+	pub fn bind (&self) {
+		unsafe {
+			gl::BindBuffer (gl::ARRAY_BUFFER, self.id);
+		}
+	}
+}
+impl Drop for VertexBuffer {
+	fn drop (&mut self) {
+		if self.id == 0 {
+			return;
+		}
+		
+		unsafe {
+			gl::DeleteBuffers (1, &self.id);
+		}
+		
+		self.id = 0;
+	}
+}
+
+
+pub struct IndexBuffer {
+	id: u32,
+	len: usize,
+	min: u32,
+	max: u32,
+}
+
+impl IndexBuffer {
+	pub fn from_slice (slice: &[u8]) -> Self {
+		let mut rdr = Cursor::new (slice);
+		
+		let mut min = None;
+		let mut max = None;
+		
+		assert_eq! (slice.len () % 4, 0);
+		
+		for _ in 0..slice.len () / 4 {
+			let idx = rdr.read_u32::<LittleEndian> ().unwrap ();
+			
+			min = match min {
+				None => Some (idx),
+				Some (min) => Some (cmp::min (min, idx)),
+			};
+			
+			max = match max {
+				None => Some (idx),
+				Some (max) => Some (cmp::max (max, idx)),
+			};
+		}
+		
+		let id = {
+			let mut id = 0;
+			unsafe {
+				gl::GenBuffers (1, &mut id);
+				gl::BindBuffer (gl::ELEMENT_ARRAY_BUFFER, id);
+				
+				gl::BufferData (gl::ELEMENT_ARRAY_BUFFER, slice.len ().try_into ().unwrap (), &slice [0] as *const u8 as *const c_void, gl::STATIC_DRAW);
+			}
+			assert! (id != 0);
+			id
+		};
+		
+		Self {
+			id,
+			len: slice.len () / 4,
+			min: min.unwrap (),
+			max: max.unwrap (),
+		}
+	}
+	
+	pub fn bind (&self) {
+		unsafe {
+			gl::BindBuffer (gl::ELEMENT_ARRAY_BUFFER, self.id);
+		}
+	}
+}
+
+impl Drop for IndexBuffer {
+	fn drop (&mut self) {
+		if self.id == 0 {
+			return;
+		}
+		
+		unsafe {
+			gl::DeleteBuffers (1, &self.id);
+		}
+		
+		self.id = 0;
+	}
+}
+
+