use glam::{Mat4, Vec3, Vec4, Quat}; use nom::{ IResult, bytes::complete::{tag}, number::complete::{le_u32}, }; use sdl2::event::Event; use sdl2::keyboard::Keycode; use std::collections::HashMap; use std::convert::TryInto; use std::ffi::{c_void, CStr, CString}; use std::fs::File; use std::io::Read; use std::path::Path; use std::time::{Duration, Instant}; mod iqm_consts { pub const VERSION: usize = 0; pub const FILESIZE: usize = 1; pub const FLAGS: usize = 2; pub const NUM_TEXT: usize = 3; pub const OFS_TEXT: usize = 4; pub const NUM_MESHES: usize = 5; pub const OFS_MESHES: usize = 6; pub const NUM_VERTEXARRAYS: usize = 7; pub const NUM_VERTEXES: usize = 8; pub const OFS_VERTEXARRAYS: usize = 9; pub const NUM_TRIANGLES: usize = 10; pub const OFS_TRIANGLES: usize = 11; pub const OFS_ADJACENCY: usize = 12; pub const NUM_JOINTS: usize = 13; pub const OFS_JOINTS: usize = 14; pub const NUM_POSES: usize = 15; pub const OFS_POSES: usize = 16; pub const NUM_ANIMS: usize = 17; pub const OFS_ANIMS: usize = 18; pub const NUM_FRAMES: usize = 19; pub const NUM_FRAMECHANNELS: usize = 20; pub const OFS_FRAMES: usize = 21; pub const OFS_BOUNDS: usize = 22; pub const NUM_COMMENT: usize = 23; pub const OFS_COMMENT: usize = 24; pub const NUM_EXTENSIONS: usize = 25; pub const OFS_EXTENSIONS: usize = 26; } mod iqm_types { pub const POSITION: u32 = 0; pub const TEXCOORD: u32 = 1; pub const NORMAL: u32 = 2; pub const TANGENT: u32 = 3; pub const BLENDINDEXES: u32 = 4; pub const BLENDWEIGHTS: u32 = 5; pub const COLOR: u32 = 6; pub const CUSTOM: u32 = 0x10; } mod iqm_formats { pub const BYTE: u32 = 0; pub const UBYTE: u32 = 1; pub const SHORT: u32 = 2; pub const USHORT: u32 = 3; pub const INT: u32 = 4; pub const UINT: u32 = 5; pub const HALF: u32 = 6; pub const FLOAT: u32 = 7; pub const DOUBLE: u32 = 8; } #[derive (Debug)] pub struct IqmMesh { name: u32, material: u32, first_vertex: u32, num_vertexes: u32, first_triangle: u32, num_triangles: u32, } #[derive (Debug)] pub struct IqmHeader { fields: [u32; 27], } #[derive (Debug)] pub struct IqmVertexArray { va_type: u32, va_flags: u32, va_format: u32, va_size: u32, va_offset: u32, } #[derive (Debug)] pub struct IqmModel <'a> { data: &'a [u8], header: IqmHeader, text: Vec , meshes: Vec , vertexarrays: Vec , } impl IqmHeader { pub fn from_slice (input: &[u8]) -> IResult <&[u8], IqmHeader> { let (input, _) = tag (b"INTERQUAKEMODEL\0")(input)?; let (input, version) = le_u32 (input)?; // I only know how to parse version 2 assert_eq! (version, 2); let mut input = input; let mut fields = [0; 27]; fields [0] = version; for index in 1..fields.len () { let (i, h) = le_u32 (input)?; input = i; fields [usize::from (index)] = h; } Ok ((input, IqmHeader { fields, })) } } impl IqmMesh { pub fn from_slice (input: &[u8]) -> IResult <&[u8], IqmMesh> { let mut result = IqmMesh { name: 0, material: 0, first_vertex: 0, num_vertexes: 0, first_triangle: 0, num_triangles: 0, }; let mut input = input; for field in [ &mut result.name, &mut result.material, &mut result.first_vertex, &mut result.num_vertexes, &mut result.first_triangle, &mut result.num_triangles, ].iter_mut () { let (i, f) = le_u32 (input)?; input = i; **field = f; } Ok ((input, result)) } } impl IqmVertexArray { pub fn from_slice (input: &[u8]) -> IResult <&[u8], IqmVertexArray> { let mut result = IqmVertexArray { va_type: 0, va_flags: 0, va_format: 0, va_size: 0, va_offset: 0, }; let mut input = input; for field in [ &mut result.va_type, &mut result.va_flags, &mut result.va_format, &mut result.va_size, &mut result.va_offset, ].iter_mut () { let (i, f) = le_u32 (input)?; input = i; **field = f; } Ok ((input, result)) } } impl <'a> IqmModel <'a> { pub fn from_slice (data: &'a [u8]) -> IqmModel <'a> { let header = IqmHeader::from_slice (data).unwrap ().1; let text = { let offset: usize = header.fields [iqm_consts::OFS_TEXT].try_into ().unwrap (); let num: usize = header.fields [iqm_consts::NUM_TEXT].try_into ().unwrap (); Vec::from (&data [offset..offset + num]) }; let meshes = { let num: usize = header.fields [iqm_consts::NUM_MESHES].try_into ().unwrap (); let mut meshes = Vec::with_capacity (num); let mesh_size = 6 * 4; let meshes_offset: usize = header.fields [iqm_consts::OFS_MESHES].try_into ().unwrap (); for i in 0..num { let offset = meshes_offset + i * mesh_size; let mesh_slice = &data [offset..offset + mesh_size]; meshes.push (IqmMesh::from_slice (mesh_slice).unwrap ().1); } meshes }; let vertexarrays = { let num: usize = header.fields [iqm_consts::NUM_VERTEXARRAYS].try_into ().unwrap (); let mut vertexarrays = Vec::with_capacity (num); let vertexarray_size = 5 * 4; let vertexarrays_offset: usize = header.fields [iqm_consts::OFS_VERTEXARRAYS].try_into ().unwrap (); for i in 0..num { let offset = vertexarrays_offset + i * vertexarray_size; let vertexarray_slice = &data [offset..offset + vertexarray_size]; let vertexarray = IqmVertexArray::from_slice (vertexarray_slice).unwrap ().1; //println! ("{:?}", vertexarray); vertexarrays.push (vertexarray); } vertexarrays }; IqmModel { data, header, text, meshes, vertexarrays, } } pub fn get_vertex_slice (&self, mesh_index: usize, vertexarray_index: usize ) -> &[u8] { let vertexarray = &self.vertexarrays [vertexarray_index]; let bytes_per_float = 4; let stride = bytes_per_float * vertexarray.va_size; let mesh = &self.meshes [mesh_index]; let offset: usize = (vertexarray.va_offset + stride * mesh.first_vertex).try_into ().unwrap (); let num_bytes: usize = (stride * mesh.num_vertexes).try_into ().unwrap (); &self.data [offset..offset + num_bytes] } pub fn get_index_slice (&self, mesh_index: usize) -> &[u8] { let mesh = &self.meshes [mesh_index]; let bytes_per_u32 = 4; let indexes_per_tri = 3; let stride = bytes_per_u32 * indexes_per_tri; let offset: usize = (self.header.fields [iqm_consts::OFS_TRIANGLES] + stride * mesh.first_triangle).try_into ().unwrap (); let num_bytes: usize = (stride * mesh.num_triangles).try_into ().unwrap (); &self.data [offset..offset + num_bytes] } } pub fn load_small_file

(name: P) -> Vec where P: AsRef { let mut f = File::open (name).unwrap (); let len = f.metadata ().unwrap ().len (); if len > 1024 * 1024 { panic! ("File is too big"); } let mut data = vec! [0u8; len.try_into ().unwrap ()]; f.read (&mut data [..]).unwrap (); data } const VERT_SHADER_SRC: &str = " #define lowp #define mediump #define highp #line 0 uniform highp mat4 uni_model; uniform highp mat4 uni_viewproj; attribute highp vec4 attr_pos; attribute mediump vec2 attr_uv; attribute lowp vec3 attr_normal; varying mediump vec2 vary_uv; varying lowp vec3 vary_normal; void main (void) { vary_uv = attr_uv; lowp vec4 light_color = vec4 (1.0); //vary_color = dot (attr_normal, object_space_light.xyz) * light_color; //vary_color.xyz = attr_normal; vary_normal = attr_normal; vec4 world_pos = uni_model * attr_pos; gl_Position = uni_viewproj * world_pos; }"; const FRAG_SHADER_SRC: &str = " #define lowp #define mediump #define highp #line 0 //uniform lowp sampler2D uni_texture; uniform lowp vec3 uni_albedo; uniform lowp vec4 uni_object_space_light; //varying lowp vec4 vary_color; varying lowp vec3 vary_normal; varying mediump vec2 vary_uv; void main (void) { //lowp vec4 albedo = texture2D (uni_texture, vary_uv); lowp vec3 normal = normalize (vary_normal); //lowp vec3 albedo = pow (vec3 (255.0 / 255.0, 154.0 / 255.0, 0.0 / 255.0), vec3 (2.0)); lowp float diffuse_factor = dot (normal, uni_object_space_light.xyz); lowp vec3 sun = max (diffuse_factor, 0.0) * vec3 (0.95, 0.9, 0.85); lowp vec3 sky = (diffuse_factor * 0.45 + 0.55) * vec3 (0.05, 0.1, 0.15); lowp vec3 diffuse_color = uni_albedo * (sun + sky); gl_FragColor = vec4 (sqrt (diffuse_color), 1.0); } "; pub struct ShaderObject { id: u32, } impl ShaderObject { pub fn id (&self) -> u32 { self.id } pub fn new (shader_type: u32, source: &str) -> Result { let id = unsafe { gl::CreateShader (shader_type) }; let sources = [ source.as_ptr () as *const i8, ]; let lengths = [ source.len ().try_into ().unwrap (), ]; let success = unsafe { gl::ShaderSource (id, sources.len ().try_into ().unwrap (), sources.as_ptr (), lengths.as_ptr ()); gl::CompileShader (id); let mut success = 0; gl::GetShaderiv (id, gl::COMPILE_STATUS, &mut success); success == 1 }; if success { Ok (ShaderObject { id, }) } else { let mut info_log = vec! [0u8; 4096]; let mut log_length = 0; unsafe { gl::GetShaderInfoLog (id, (info_log.len () - 1).try_into ().unwrap (), &mut log_length, info_log.as_mut_ptr () as *mut i8); } info_log.truncate (log_length.try_into ().unwrap ()); let info = String::from_utf8 (info_log).unwrap (); Err (info) } } } impl Drop for ShaderObject { fn drop (&mut self) { unsafe { gl::DeleteShader (self.id); } } } pub struct ShaderProgram { id: u32, } impl ShaderProgram { pub fn new (vert: &ShaderObject, frag: &ShaderObject) -> Result { let id = unsafe { gl::CreateProgram () }; unsafe { gl::AttachShader (id, vert.id ()); gl::AttachShader (id, frag.id ()); gl::LinkProgram (id); } let success = unsafe { let mut success = 0; gl::GetProgramiv (id, gl::LINK_STATUS, &mut success); success == 1 }; if success { Ok (ShaderProgram { id, }) } else { let mut info_log = vec! [0u8; 4096]; let mut log_length = 0; unsafe { gl::GetProgramInfoLog (id, (info_log.len () - 1).try_into ().unwrap (), &mut log_length, info_log.as_mut_ptr () as *mut i8); } info_log.truncate (log_length.try_into ().unwrap ()); let info = String::from_utf8 (info_log).unwrap (); Err (info) } } pub fn get_uniform_location (&self, name: &CStr) -> i32 { unsafe { gl::UseProgram (self.id); gl::GetUniformLocation (self.id, name.as_ptr ()) } } pub fn get_attribute_location (&self, name: &CStr) -> i32 { unsafe { gl::UseProgram (self.id); gl::GetAttribLocation (self.id, name.as_ptr ()) } } } impl Drop for ShaderProgram { fn drop (&mut self) { unsafe { gl::DeleteProgram (self.id); } } } fn enable_vertex_attrib_array (id: Option ) { match id { Some (id) => unsafe { gl::EnableVertexAttribArray (id); }, _ => (), } } unsafe fn vertex_attrib_pointer (id: Option , num_coords: i32, slice: &[u8]) { const FALSE_U8: u8 = 0; const FLOAT_SIZE: i32 = 4; match id { Some (id) => { gl::VertexAttribPointer (id, num_coords, gl::FLOAT, FALSE_U8, FLOAT_SIZE * num_coords, &slice [0] as *const u8 as *const c_void); }, _ => (), } } fn main () { let sdl_context = sdl2::init ().unwrap (); let video_subsystem = sdl_context.video ().unwrap (); let window = video_subsystem.window ("OpenGL? In my Rust?", 1280, 720) .position_centered () .opengl () .build () .unwrap (); gl::load_with (|s| { let result = video_subsystem.gl_get_proc_address (s) as *const _; //println! ("{:?}", result); result }); assert! (gl::ClearColor::is_loaded ()); let gl_ctx = window.gl_create_context ().unwrap (); window.gl_make_current (&gl_ctx).unwrap (); // I love how with Rust I can throw unwrap ()s everywhere // It's safer than C / C++'s default behavior of unchecked errors // It's more programmer-friendly and explicit than C#'s unchecked // exceptions that can appear almost anywhere at runtime with no // compile-time warning // And I'm still not actually checking errors - Just checkmarking // that I know where they are. let vert_shader = ShaderObject::new (gl::VERTEX_SHADER, VERT_SHADER_SRC).unwrap (); let frag_shader = ShaderObject::new (gl::FRAGMENT_SHADER, FRAG_SHADER_SRC).unwrap (); let shader_program = ShaderProgram::new (&vert_shader, &frag_shader).unwrap (); let unis: HashMap <_, _> = vec! [ "model", "viewproj", "object_space_light", "albedo", ].iter () .map (|name| { let mut s = String::from ("uni_"); s.push_str (name); let c_str = CString::new (s.as_bytes ()).unwrap (); let loc = shader_program.get_uniform_location (&c_str); println! ("Uni {} --> {}", name, loc); (String::from (*name), loc) }) .collect (); //println! ("uni_model: {}", unis ["model"]); //println! ("uni_viewproj: {}", unis ["viewproj"]); let attrs: HashMap <_, Option > = vec! [ "pos", "uv", "normal", ].iter () .map (|name| { let mut s = String::from ("attr_"); s.push_str (name); let c_str = CString::new (s.as_bytes ()).unwrap (); let loc = shader_program.get_attribute_location (&c_str); let loc = match loc.try_into () { Ok (i) => Some (i), _ => { println! ("Attribute {} not found - Optimized out?", name); None }, }; (String::from (*name), loc) }) .collect (); //println! ("attr_pos: {}", attrs ["pos"]); let tri_mesh: Vec = vec! [ 0.0, 0.0, 1.0, 0.0, 1.0, 1.0, ]; let model_data = load_small_file ("pumpking.iqm"); let model = IqmModel::from_slice (&model_data [..]); let vertex_slice = model.get_vertex_slice (0, 0); let normal_slice = model.get_vertex_slice (0, 2); let index_slice = model.get_index_slice (0); let id_mat = Mat4::identity (); let view_mat: Vec = vec! [ 0.3125, 0.0, 0.0, 0.0, 0.0, 0.5, 0.0, 0.0, 0.0, 0.0, 0.3125, 0.0, 0.0, 0.0, 0.0, 1.0, ]; let indexes: Vec = vec! [0, 1, 2]; const FALSE_U8: u8 = 0; unsafe { enable_vertex_attrib_array (attrs ["pos"]); enable_vertex_attrib_array (attrs ["normal"]); gl::Enable (gl::DEPTH_TEST); let num_coords = 3; let stride = 4 * num_coords; gl::UniformMatrix4fv (unis ["viewproj"], 1, FALSE_U8, &view_mat [0]); } let mut last_frame_time = Instant::now (); let mut frame = 0; let mut timestep_accum = Duration::from_millis (0); let mut event_pump = sdl_context.event_pump ().unwrap (); 'running: loop { let frame_time = Instant::now (); // Take 60 steps every 1,000 milliseconds. // I know this is a float, but since we're multiplying it will // be deterministic, since it's a whole number. let fps_num = 60.0; let fps_den = 1000; timestep_accum += (frame_time - last_frame_time).mul_f32 (fps_num); for _ in 0..4 { if timestep_accum > Duration::from_millis (fps_den) { frame += 1; timestep_accum -= Duration::from_millis (fps_den); } else { break; } } last_frame_time = frame_time; let _mouse = event_pump.mouse_state (); for event in event_pump.poll_iter() { match event { Event::Quit {..} | Event::KeyDown { keycode: Some (Keycode::Escape), .. } => { break 'running }, _ => (), } } window.gl_make_current (&gl_ctx).unwrap (); let longitude = (frame as f32).to_radians (); let latitude = (frame as f32 / 5.0).to_radians ().sin () * 45.0f32.to_radians () - 120.0f32.to_radians (); let model_mat = Mat4::from_rotation_x (latitude) * Mat4::from_rotation_z (longitude) * Mat4::from_translation (Vec3::from ((0.0, 0.0, -1.0))) ; let light = Vec4::from ((0.0, 0.0, 0.0, 1.0)); let object_space_light = model_mat.inverse () * light; let orange = Vec3::from ((255.0 / 255.0, 154.0 / 255.0, 0.0 / 255.0)); let green = Vec3::from ((14.0 / 255.0, 127.0 / 255.0, 24.0 / 255.0)); let orange = orange * orange; let green = green * green; unsafe { gl::ClearColor (1.0f32, 0.0f32, 1.0f32, 1.0f32); gl::Clear (gl::COLOR_BUFFER_BIT | gl::DEPTH_BUFFER_BIT); gl::Disable (gl::CULL_FACE); gl::UniformMatrix4fv (unis ["model"], 1, FALSE_U8, &model_mat as *const Mat4 as *const f32); gl::Uniform4fv (unis ["object_space_light"], 1, &object_space_light as *const Vec4 as *const f32); gl::Uniform3fv (unis ["albedo"], 1, &orange as *const Vec3 as *const f32); vertex_attrib_pointer (attrs ["pos"], 3, model.get_vertex_slice (0, 0)); vertex_attrib_pointer (attrs ["normal"], 3, model.get_vertex_slice (0, 2)); gl::DrawElements (gl::TRIANGLES, (model.meshes [0].num_triangles * 3) as i32, gl::UNSIGNED_INT, &index_slice [0] as *const u8 as *const c_void); if false { gl::Uniform3fv (unis ["albedo"], 1, &green as *const Vec3 as *const f32); vertex_attrib_pointer (attrs ["pos"], 3, model.get_vertex_slice (1, 0)); vertex_attrib_pointer (attrs ["normal"], 3, model.get_vertex_slice (1, 2)); gl::DrawElements (gl::TRIANGLES, (model.meshes [1].num_triangles * 3) as i32, gl::UNSIGNED_INT, &index_slice [1] as *const u8 as *const c_void); } } window.gl_swap_window (); ::std::thread::sleep (Duration::from_millis (15)); } } #[cfg (test)] mod tests { use super::*; #[test] pub fn iqm () { let data = load_small_file ("pumpking.iqm"); { let model = IqmHeader::from_slice (&data [..]).unwrap ().1; assert_eq! (model.fields [1], 90368); assert_eq! (model.fields [2], 0); assert_eq! (model.fields [iqm_consts::VERSION], 2); } { let model = IqmModel::from_slice (&data [..]); println! ("{:?}", model.meshes); println! ("{:?}", model.vertexarrays); } } }