servo/components/canvas/webgl_paint_task.rs
Patrick Walton bb99b2f3c8 script: Make most of 2D canvas and WebGL run over IPC.
To actually make the multiprocess communication work, we'll need to
reroute the task creation to the pipeline or the compositor. But this
works as a first step.
2015-07-25 00:50:12 -07:00

509 lines
18 KiB
Rust

/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
use canvas_traits::{CanvasMsg, CanvasWebGLMsg, CanvasCommonMsg, FromLayoutMsg, FromPaintMsg};
use canvas_traits::{WebGLShaderParameter, WebGLFramebufferBindingRequest};
use euclid::size::Size2D;
use core::nonzero::NonZero;
use gleam::gl;
use gleam::gl::types::{GLsizei};
use util::task::spawn_named;
use std::borrow::ToOwned;
use std::slice::bytes::copy_memory;
use std::sync::mpsc::{channel, Sender};
use util::vec::byte_swap;
use layers::platform::surface::NativeSurface;
use offscreen_gl_context::{GLContext, GLContextAttributes, ColorAttachmentType};
use ipc_channel::ipc::{self, IpcSender, IpcSharedMemory};
use ipc_channel::router::ROUTER;
pub struct WebGLPaintTask {
size: Size2D<i32>,
original_context_size: Size2D<i32>,
gl_context: GLContext,
}
// This allows trying to create the PaintTask
// before creating the thread
unsafe impl Send for WebGLPaintTask {}
impl WebGLPaintTask {
fn new(size: Size2D<i32>, attrs: GLContextAttributes) -> Result<WebGLPaintTask, &'static str> {
let context = try!(
GLContext::create_offscreen_with_color_attachment(
size, attrs, ColorAttachmentType::TextureWithSurface));
// NOTE: As of right now this is always equal to the size parameter,
// but this doesn't have to be true. Firefox after failing with
// the requested size, tries with the nearest powers of two, for example.
let real_size = context.borrow_draw_buffer().unwrap().size();
Ok(WebGLPaintTask {
size: real_size,
original_context_size: real_size,
gl_context: context
})
}
pub fn handle_webgl_message(&self, message: CanvasWebGLMsg) {
match message {
CanvasWebGLMsg::GetContextAttributes(sender) =>
self.get_context_attributes(sender),
CanvasWebGLMsg::ActiveTexture(target) =>
self.active_texture(target),
CanvasWebGLMsg::BlendColor(r, g, b, a) =>
self.blend_color(r, g, b, a),
CanvasWebGLMsg::BlendEquation(mode) =>
self.blend_equation(mode),
CanvasWebGLMsg::BlendEquationSeparate(mode_rgb, mode_alpha) =>
self.blend_equation_separate(mode_rgb, mode_alpha),
CanvasWebGLMsg::BlendFunc(src, dest) =>
self.blend_func(src, dest),
CanvasWebGLMsg::BlendFuncSeparate(src_rgb, dest_rgb, src_alpha, dest_alpha) =>
self.blend_func_separate(src_rgb, dest_rgb, src_alpha, dest_alpha),
CanvasWebGLMsg::AttachShader(program_id, shader_id) =>
self.attach_shader(program_id, shader_id),
CanvasWebGLMsg::BufferData(buffer_type, data, usage) =>
self.buffer_data(buffer_type, data, usage),
CanvasWebGLMsg::Clear(mask) =>
self.clear(mask),
CanvasWebGLMsg::ClearColor(r, g, b, a) =>
self.clear_color(r, g, b, a),
CanvasWebGLMsg::DrawArrays(mode, first, count) =>
self.draw_arrays(mode, first, count),
CanvasWebGLMsg::EnableVertexAttribArray(attrib_id) =>
self.enable_vertex_attrib_array(attrib_id),
CanvasWebGLMsg::GetAttribLocation(program_id, name, chan) =>
self.get_attrib_location(program_id, name, chan),
CanvasWebGLMsg::GetShaderInfoLog(shader_id, chan) =>
self.get_shader_info_log(shader_id, chan),
CanvasWebGLMsg::GetShaderParameter(shader_id, param_id, chan) =>
self.get_shader_parameter(shader_id, param_id, chan),
CanvasWebGLMsg::GetUniformLocation(program_id, name, chan) =>
self.get_uniform_location(program_id, name, chan),
CanvasWebGLMsg::CompileShader(shader_id) =>
self.compile_shader(shader_id),
CanvasWebGLMsg::CreateBuffer(chan) =>
self.create_buffer(chan),
CanvasWebGLMsg::CreateFramebuffer(chan) =>
self.create_framebuffer(chan),
CanvasWebGLMsg::CreateRenderbuffer(chan) =>
self.create_renderbuffer(chan),
CanvasWebGLMsg::CreateTexture(chan) =>
self.create_texture(chan),
CanvasWebGLMsg::CreateProgram(chan) =>
self.create_program(chan),
CanvasWebGLMsg::CreateShader(shader_type, chan) =>
self.create_shader(shader_type, chan),
CanvasWebGLMsg::DeleteBuffer(id) =>
self.delete_buffer(id),
CanvasWebGLMsg::DeleteFramebuffer(id) =>
self.delete_framebuffer(id),
CanvasWebGLMsg::DeleteRenderbuffer(id) =>
self.delete_renderbuffer(id),
CanvasWebGLMsg::DeleteTexture(id) =>
self.delete_texture(id),
CanvasWebGLMsg::DeleteProgram(id) =>
self.delete_program(id),
CanvasWebGLMsg::DeleteShader(id) =>
self.delete_shader(id),
CanvasWebGLMsg::BindBuffer(target, id) =>
self.bind_buffer(target, id),
CanvasWebGLMsg::BindFramebuffer(target, request) =>
self.bind_framebuffer(target, request),
CanvasWebGLMsg::BindRenderbuffer(target, id) =>
self.bind_renderbuffer(target, id),
CanvasWebGLMsg::BindTexture(target, id) =>
self.bind_texture(target, id),
CanvasWebGLMsg::LinkProgram(program_id) =>
self.link_program(program_id),
CanvasWebGLMsg::ShaderSource(shader_id, source) =>
self.shader_source(shader_id, source),
CanvasWebGLMsg::Uniform4fv(uniform_id, data) =>
self.uniform_4fv(uniform_id, data),
CanvasWebGLMsg::UseProgram(program_id) =>
self.use_program(program_id),
CanvasWebGLMsg::VertexAttribPointer2f(attrib_id, size, normalized, stride, offset) =>
self.vertex_attrib_pointer_f32(attrib_id, size, normalized, stride, offset),
CanvasWebGLMsg::Viewport(x, y, width, height) =>
self.viewport(x, y, width, height),
CanvasWebGLMsg::DrawingBufferWidth(sender) =>
self.send_drawing_buffer_width(sender),
CanvasWebGLMsg::DrawingBufferHeight(sender) =>
self.send_drawing_buffer_height(sender),
}
}
/// Creates a new `WebGLPaintTask` and returns the out-of-process sender and the in-process
/// sender for it.
pub fn start(size: Size2D<i32>, attrs: GLContextAttributes)
-> Result<(IpcSender<CanvasMsg>, Sender<CanvasMsg>), &'static str> {
let (out_of_process_chan, out_of_process_port) = ipc::channel::<CanvasMsg>().unwrap();
let (in_process_chan, in_process_port) = channel();
ROUTER.route_ipc_receiver_to_mpsc_sender(out_of_process_port, in_process_chan.clone());
let mut painter = try!(WebGLPaintTask::new(size, attrs));
spawn_named("WebGLTask".to_owned(), move || {
painter.init();
loop {
match in_process_port.recv().unwrap() {
CanvasMsg::WebGL(message) => painter.handle_webgl_message(message),
CanvasMsg::Common(message) => {
match message {
CanvasCommonMsg::Close => break,
// TODO(ecoal95): handle error nicely
CanvasCommonMsg::Recreate(size) => painter.recreate(size).unwrap(),
}
},
CanvasMsg::FromLayout(message) => {
match message {
FromLayoutMsg::SendPixelContents(chan) =>
painter.send_pixel_contents(chan),
}
}
CanvasMsg::FromPaint(message) => {
match message {
FromPaintMsg::SendNativeSurface(chan) =>
painter.send_native_surface(chan),
}
}
CanvasMsg::Canvas2d(_) => panic!("Wrong message sent to WebGLTask"),
}
}
});
Ok((out_of_process_chan, in_process_chan))
}
#[inline]
fn get_context_attributes(&self, sender: IpcSender<GLContextAttributes>) {
sender.send(*self.gl_context.borrow_attributes()).unwrap()
}
#[inline]
fn send_drawing_buffer_width(&self, sender: IpcSender<i32>) {
sender.send(self.size.width).unwrap()
}
#[inline]
fn send_drawing_buffer_height(&self, sender: IpcSender<i32>) {
sender.send(self.size.height).unwrap()
}
#[inline]
fn active_texture(&self, texture: u32) {
gl::active_texture(texture);
}
#[inline]
fn blend_color(&self, r: f32, g: f32, b: f32, a: f32) {
gl::blend_color(r, g, b, a);
}
#[inline]
fn blend_equation(&self, mode: u32) {
gl::blend_equation(mode);
}
#[inline]
fn blend_equation_separate(&self, mode_rgb: u32, mode_alpha: u32) {
gl::blend_equation_separate(mode_rgb, mode_alpha);
}
#[inline]
fn blend_func(&self, src_factor: u32, dest_factor: u32) {
gl::blend_func(src_factor, dest_factor);
}
#[inline]
fn blend_func_separate(&self,
src_rgb_factor: u32,
dest_rgb_factor: u32,
src_alpha_factor: u32,
dest_alpha_factor: u32) {
gl::blend_func_separate(src_rgb_factor,
dest_rgb_factor,
src_alpha_factor,
dest_alpha_factor);
}
#[inline]
fn attach_shader(&self, program_id: u32, shader_id: u32) {
gl::attach_shader(program_id, shader_id);
}
#[inline]
fn buffer_data(&self, buffer_type: u32, data: Vec<f32>, usage: u32) {
gl::buffer_data(buffer_type, &data, usage);
}
#[inline]
fn clear(&self, mask: u32) {
gl::clear(mask);
}
#[inline]
fn clear_color(&self, r: f32, g: f32, b: f32, a: f32) {
gl::clear_color(r, g, b, a);
}
fn create_buffer(&self, chan: IpcSender<Option<NonZero<u32>>>) {
let buffer = gl::gen_buffers(1)[0];
let buffer = if buffer == 0 {
None
} else {
Some(unsafe { NonZero::new(buffer) })
};
chan.send(buffer).unwrap();
}
fn create_framebuffer(&self, chan: IpcSender<Option<NonZero<u32>>>) {
let framebuffer = gl::gen_framebuffers(1)[0];
let framebuffer = if framebuffer == 0 {
None
} else {
Some(unsafe { NonZero::new(framebuffer) })
};
chan.send(framebuffer).unwrap();
}
fn create_renderbuffer(&self, chan: IpcSender<Option<NonZero<u32>>>) {
let renderbuffer = gl::gen_renderbuffers(1)[0];
let renderbuffer = if renderbuffer == 0 {
None
} else {
Some(unsafe { NonZero::new(renderbuffer) })
};
chan.send(renderbuffer).unwrap();
}
fn create_texture(&self, chan: IpcSender<Option<NonZero<u32>>>) {
let texture = gl::gen_framebuffers(1)[0];
let texture = if texture == 0 {
None
} else {
Some(unsafe { NonZero::new(texture) })
};
chan.send(texture).unwrap();
}
fn create_program(&self, chan: IpcSender<Option<NonZero<u32>>>) {
let program = gl::create_program();
let program = if program == 0 {
None
} else {
Some(unsafe { NonZero::new(program) })
};
chan.send(program).unwrap();
}
fn create_shader(&self, shader_type: u32, chan: IpcSender<Option<NonZero<u32>>>) {
let shader = gl::create_shader(shader_type);
let shader = if shader == 0 {
None
} else {
Some(unsafe { NonZero::new(shader) })
};
chan.send(shader).unwrap();
}
#[inline]
fn delete_buffer(&self, id: u32) {
gl::delete_buffers(&[id]);
}
#[inline]
fn delete_renderbuffer(&self, id: u32) {
gl::delete_renderbuffers(&[id]);
}
#[inline]
fn delete_framebuffer(&self, id: u32) {
gl::delete_framebuffers(&[id]);
}
#[inline]
fn delete_texture(&self, id: u32) {
gl::delete_textures(&[id]);
}
#[inline]
fn delete_program(&self, id: u32) {
gl::delete_program(id);
}
#[inline]
fn delete_shader(&self, id: u32) {
gl::delete_shader(id);
}
#[inline]
fn bind_buffer(&self, target: u32, id: u32) {
gl::bind_buffer(target, id);
}
#[inline]
fn bind_framebuffer(&self, target: u32, request: WebGLFramebufferBindingRequest) {
let id = match request {
WebGLFramebufferBindingRequest::Explicit(id) => id,
WebGLFramebufferBindingRequest::Default =>
self.gl_context.borrow_draw_buffer().unwrap().get_framebuffer(),
};
gl::bind_framebuffer(target, id);
}
#[inline]
fn bind_renderbuffer(&self, target: u32, id: u32) {
gl::bind_renderbuffer(target, id);
}
#[inline]
fn bind_texture(&self, target: u32, id: u32) {
gl::bind_texture(target, id);
}
// TODO(ecoal95): This is not spec-compliant, we must check
// the version of GLSL used. This functionality should probably
// be in the WebGLShader object
#[inline]
fn compile_shader(&self, shader_id: u32) {
gl::compile_shader(shader_id);
}
#[inline]
fn draw_arrays(&self, mode: u32, first: i32, count: i32) {
gl::draw_arrays(mode, first, count);
}
#[inline]
fn enable_vertex_attrib_array(&self, attrib_id: u32) {
gl::enable_vertex_attrib_array(attrib_id);
}
fn get_attrib_location(&self, program_id: u32, name: String, chan: IpcSender<Option<i32>> ) {
let attrib_location = gl::get_attrib_location(program_id, &name);
let attrib_location = if attrib_location == -1 {
None
} else {
Some(attrib_location)
};
chan.send(attrib_location).unwrap();
}
fn get_shader_info_log(&self, shader_id: u32, chan: IpcSender<Option<String>>) {
// TODO(ecoal95): Right now we always return a value, we should
// check for gl errors and return None there
let info = gl::get_shader_info_log(shader_id);
chan.send(Some(info)).unwrap();
}
fn get_shader_parameter(&self,
shader_id: u32,
param_id: u32,
chan: IpcSender<WebGLShaderParameter>) {
let result = match param_id {
gl::SHADER_TYPE =>
WebGLShaderParameter::Int(gl::get_shader_iv(shader_id, param_id)),
gl::DELETE_STATUS | gl::COMPILE_STATUS =>
WebGLShaderParameter::Bool(gl::get_shader_iv(shader_id, param_id) != 0),
_ => panic!("Unexpected shader parameter type"),
};
chan.send(result).unwrap();
}
fn get_uniform_location(&self, program_id: u32, name: String, chan: IpcSender<Option<i32>>) {
let location = gl::get_uniform_location(program_id, &name);
let location = if location == -1 {
None
} else {
Some(location)
};
chan.send(location).unwrap();
}
#[inline]
fn link_program(&self, program_id: u32) {
gl::link_program(program_id);
}
#[inline]
fn shader_source(&self, shader_id: u32, source: String) {
gl::shader_source(shader_id, &[source.as_bytes()]);
}
#[inline]
fn uniform_4fv(&self, uniform_id: i32, data: Vec<f32>) {
gl::uniform_4f(uniform_id, data[0], data[1], data[2], data[3]);
}
#[inline]
fn use_program(&self, program_id: u32) {
gl::use_program(program_id);
}
#[inline]
fn vertex_attrib_pointer_f32(&self, attrib_id: u32, size: i32,
normalized: bool, stride: i32, offset: i64) {
gl::vertex_attrib_pointer_f32(attrib_id, size, normalized, stride, offset as u32);
}
#[inline]
fn viewport(&self, x: i32, y: i32, width: i32, height: i32) {
gl::viewport(x, y, width, height);
}
fn send_pixel_contents(&mut self, chan: IpcSender<IpcSharedMemory>) {
// FIXME(#5652, dmarcos) Instead of a readback strategy we have
// to layerize the canvas.
// TODO(pcwalton): We'd save a copy if we had an `IpcSharedMemoryBuilder` abstraction that
// allowed you to mutate in-place before freezing the object for sending.
let width = self.size.width as usize;
let height = self.size.height as usize;
let mut pixels = gl::read_pixels(0, 0,
self.size.width as gl::GLsizei,
self.size.height as gl::GLsizei,
gl::RGBA, gl::UNSIGNED_BYTE);
// flip image vertically (texture is upside down)
let orig_pixels = pixels.clone();
let stride = width * 4;
for y in 0..height {
let dst_start = y * stride;
let src_start = (height - y - 1) * stride;
let src_slice = &orig_pixels[src_start .. src_start + stride];
copy_memory(&src_slice[..stride], &mut pixels[dst_start .. dst_start + stride]);
}
// rgba -> bgra
byte_swap(&mut pixels);
chan.send(IpcSharedMemory::from_bytes(&pixels[..])).unwrap();
}
fn send_native_surface(&self, _: Sender<NativeSurface>) {
// FIXME(ecoal95): We need to make a clone of the surface in order to
// implement this
unimplemented!()
}
fn recreate(&mut self, size: Size2D<i32>) -> Result<(), &'static str> {
if size.width > self.original_context_size.width ||
size.height > self.original_context_size.height {
try!(self.gl_context.resize(size));
self.size = self.gl_context.borrow_draw_buffer().unwrap().size();
} else {
self.size = size;
unsafe { gl::Scissor(0, 0, size.width, size.height); }
}
Ok(())
}
fn init(&mut self) {
self.gl_context.make_current().unwrap();
}
}