#![warn(missing_docs)]

//! Wrend is a ***W***ebGL2 ***Rend***ering library for making Rust/JavaScript + WebGL development easier and safer.
//!
//! Wrend provides an organized system for building custom rendering pipelines: you tell Wrend *how* all of your graphical resources
//! relate to one another through user-specified ids and callbacks, and it does all the work of actually putting things together.
//! It also comes with some out-of-the-box nice-to-have abstractions like recording canvas output and animation frame scheduling,
//! as well as automatic clean-up.
//!
//! Though most of the demo app examples are built using Yew, `wrend` itself is framework agnostic  and is designed
//! to be used in a variety of settings with diverse rendering pipelines, including contexts like React and
//! raw HTML & JavaScript.
//!
//! ## Overview
//!
//! ### Links
//!
//! The fundamental organizing components of Wrend are `links`, such as [`ProgramLink`], [`AttributeLink`],
//! and [`UniformLink`],  which get appended to a [RendererDataBuilder]. These links tell `wrend` how your data
//! should be created and how each resource relates to all the other resources in your pipeline.
//!
//! ### Callbacks
//!
//! Many links accept some sort of callback, which is used to create a particular resource in your  build pipeline.
//!
//! For example, [`BufferLink`] accepts a [`BufferCreateCallback`], which is called during the build process to
//! acquire a [`web_sys::WebGlBuffer`]. In this callback, you are free to initialize your [`web_sys::WebGlBuffer`]
//! however you like.
//!
//! ### Ids
//!
//! Most resources such as shaders, [`Uniform`]s and [`Attribute`]s retrieve resources using unique [`Id`]s, which can be
//! any data type that implements the [`Id`] trait. These Ids help Wrend understand how your data fits together.
//!
//! For example, you can load shaders into the build pipeline using [`RendererDataBuilder::add_vertex_shader_src`].
//! Then, when creating a [`ProgramLink`], you can refer to that shader using its `VertexShaderId` to link that shader
//! to any number of programs you create.
//!
//! ### Build
//!
//! Once all resources and `links` have been added to the [RendererDataBuilder], the pipeline can be built
//! on using [RendererDataBuilder::build_renderer].
//!
//! # Panics
//!
//! There are very few locations in which Rust code can panic in `wrend`, and those that exist are being slimmed down.
//!
//! The primary locations that *can* are where JavaScript types such as arrays are passed into Rust--because these types must be converted
//! to WebAssembly, there is currently the chance for panic if the wrong type is supplied. If using TypeScript, you should see TypeScript errors
//! for any incorrect types supplied, as the library as a whole is strongly typed.
//!
//! A long term goal of `wrend` is to provide matchable errors (or `catch`able errors in JavaScript) for all fallible operations.
//!
//! # Example
//!
//! The following is a "Hello, triangle!" example (the equivalent of "Hello, world!" for WebGL)
//!
//! ```no_run
//! use js_sys::Float32Array;
//! use wasm_bindgen::{prelude::*, JsCast};
//! use web_sys::{window, HtmlCanvasElement, WebGl2RenderingContext};
//! use wrend::{
//!     AttributeCreateContext, AttributeLink, BufferCreateContext, BufferLink, Id, IdDefault, IdName,
//!     ProgramLink, Renderer, RendererData,
//! };
//!
//! #[derive(Clone, Copy, PartialEq, Eq, Hash, Debug, Default)]
//! pub struct ProgramId;
//!
//! impl Id for ProgramId {}
//!
//! #[derive(Clone, Copy, PartialEq, Eq, Hash, Debug, Default)]
//! pub struct VaoId;
//!
//! impl Id for VaoId {}
//!
//! #[derive(Clone, Copy, PartialEq, Eq, Hash, Debug)]
//! pub enum BufferId {
//!     VertexBuffer,
//! }
//!
//! impl Id for BufferId {}
//!
//! impl Default for BufferId {
//!     fn default() -> Self {
//!         Self::VertexBuffer
//!     }
//! }
//!
//! impl IdName for BufferId {
//!     fn name(&self) -> String {
//!         match self {
//!             BufferId::VertexBuffer => "a_position".to_string(),
//!         }
//!     }
//! }
//!
//! #[derive(Clone, Default, Copy, PartialEq, Eq, Hash, Debug)]
//! pub struct VertexShaderId;
//!
//! impl Id for VertexShaderId {}
//!
//! #[derive(Clone, Default, Copy, PartialEq, Eq, Hash, Debug)]
//! pub struct FragmentShaderId;
//!
//! impl Id for FragmentShaderId {}
//!
//! #[derive(Clone, Default, Copy, PartialEq, Eq, Hash, Debug)]
//! pub struct PositionAttributeId;
//!
//! impl Id for PositionAttributeId {}
//!
//! impl IdName for PositionAttributeId {
//!     fn name(&self) -> String {
//!         String::from("a_position")
//!     }
//! }
//!
//! #[derive(Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Default)]
//! struct AppState {
//!     count: u32,
//! }
//!
//! const VERTEX_SHADER: &str = r#"#version 300 es
//! in vec2 a_position;
//! out vec2 v_position;
//!
//! void main() {
//!     gl_Position = vec4(a_position, 0, 1);
//!     vec2 zero_to_two = a_position + 1.0;
//!     vec2 zero_to_one = zero_to_two * 0.5;
//!     v_position = zero_to_one;
//! }"#;
//!
//!
//! const FRAGMENT_SHADER: &str = r#"#version 300 es
//! precision mediump float;
//! in vec2 v_position;
//! out vec4 out_color;
//!
//! void main() {
//!   out_color = vec4(v_position.x, v_position.y, v_position.x * 0.5 + v_position.y * 0.5, 1);
//! }"#;
//!
//! pub fn main() -> Result<(), JsValue> {
//!     let canvas: HtmlCanvasElement = window()
//!         .unwrap()
//!         .document()
//!         .unwrap()
//!         .query_selector("canvas")
//!         .unwrap()
//!         .unwrap()
//!         .dyn_into()
//!         .unwrap();
//!
//!     let app_state = AppState::default();
//!
//!     let program_link = ProgramLink::new(ProgramId, VertexShaderId, FragmentShaderId);
//!
//!     let vertex_buffer_link =
//!         BufferLink::new(BufferId::VertexBuffer, |ctx: &BufferCreateContext| {
//!             let gl = ctx.gl();
//!             let buffer = gl.create_buffer().unwrap();
//!             gl.bind_buffer(WebGl2RenderingContext::ARRAY_BUFFER, Some(&buffer));
//!             let vertex_array = unsafe { Float32Array::view(&[-0.0, 1.0, 1.0, -1.0, -1.0, -1.0]) };
//!             gl.buffer_data_with_array_buffer_view(
//!                 WebGl2RenderingContext::ARRAY_BUFFER,
//!                 &vertex_array,
//!                 WebGl2RenderingContext::STATIC_DRAW,
//!             );
//!
//!             buffer
//!         });
//!
//!     let a_position_link = AttributeLink::new(
//!         VaoId,
//!         BufferId::VertexBuffer,
//!         PositionAttributeId,
//!         |ctx: &AttributeCreateContext| {
//!             let gl = ctx.gl();
//!             let attribute_location = ctx.attribute_location();
//!             let webgl_buffer = ctx.webgl_buffer();
//!             gl.bind_buffer(WebGl2RenderingContext::ARRAY_BUFFER, Some(webgl_buffer));
//!             gl.vertex_attrib_pointer_with_i32(
//!                 attribute_location.into(),
//!                 2,
//!                 WebGl2RenderingContext::FLOAT,
//!                 false,
//!                 0,
//!                 0,
//!             );
//!         },
//!     );
//!
//!     let render_callback = |renderer_data: &RendererData<
//!         VertexShaderId,
//!         FragmentShaderId,
//!         ProgramId,
//!         IdDefault,
//!         BufferId,
//!         PositionAttributeId,
//!         IdDefault,
//!         IdDefault,
//!         IdDefault,
//!         VaoId,
//!         AppState,
//!     >| {
//!         let gl = renderer_data.gl();
//!         let canvas: HtmlCanvasElement = gl.canvas().unwrap().dyn_into().unwrap();
//!
//!         renderer_data.use_program(&ProgramId);
//!         renderer_data.use_vao(&VaoId);
//!
//!         gl.viewport(0, 0, canvas.width() as i32, canvas.height() as i32);
//!         gl.clear_color(0.0, 0.0, 0.0, 0.0);
//!         gl.clear(WebGl2RenderingContext::COLOR_BUFFER_BIT);
//!         gl.draw_arrays(WebGl2RenderingContext::TRIANGLES, 0, 3);
//!     };
//!
//!     let mut render_builder = Renderer::builder();
//!
//!     render_builder
//!         .set_canvas(canvas)
//!         .set_user_ctx(app_state)
//!         .add_vertex_shader_src(VertexShaderId, VERTEX_SHADER.to_string())
//!         .add_fragment_shader_src(FragmentShaderId, FRAGMENT_SHADER.to_string())
//!         .add_program_link(program_link)
//!         .add_buffer_link(vertex_buffer_link)
//!         .add_attribute_link(a_position_link)
//!         .add_vao_link(VaoId)
//!         .set_render_callback(render_callback);
//!
//!     let renderer = render_builder
//!         .build_renderer()
//!         .expect("Renderer should successfully build");
//!
//!     renderer.render();
//!
//!     Ok(())
//! }
//! ```
//!
//! # Demos
//!
//! todo
//!
//! ## Future Work
//!
//! Currently, wrend only supports build pipelines where all resources are initialized up front.
//! That is, no *new* textures, buffers, uniforms can be added after the pipeline has been initialized.

mod animation;
mod attributes;
mod buffers;
mod callbacks;
mod constants;
mod framebuffers;
mod ids;
mod math;
mod programs;
mod recording;
mod renderer_data;
mod renderers;
mod shaders;
mod textures;
mod transform_feedback;
mod types;
mod uniforms;
mod utils;

pub(crate) use recording::*;

pub use animation::*;
pub use attributes::*;
pub use buffers::*;
pub use callbacks::*;
pub use constants::*;
pub use framebuffers::*;
pub use ids::*;
pub use math::*;
pub use programs::*;
pub use renderer_data::*;
pub use renderers::*;
pub use shaders::*;
pub use textures::*;
pub use transform_feedback::*;
pub use types::*;
pub use uniforms::*;
pub use utils::*;