servo/components/canvas/webgl_paint_task.rs
2015-09-24 02:12:45 +05:30

392 lines
16 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::{CanvasCommonMsg, CanvasMsg, CanvasWebGLMsg, FromLayoutMsg, FromPaintMsg};
use canvas_traits::{WebGLFramebufferBindingRequest, WebGLShaderParameter};
use core::nonzero::NonZero;
use euclid::size::Size2D;
use gleam::gl;
use gleam::gl::types::{GLsizei};
use ipc_channel::ipc::{self, IpcSender, IpcSharedMemory};
use ipc_channel::router::ROUTER;
use layers::platform::surface::NativeSurface;
use offscreen_gl_context::{ColorAttachmentType, GLContext, GLContextAttributes};
use std::borrow::ToOwned;
use std::slice::bytes::copy_memory;
use std::sync::mpsc::{Sender, channel};
use util::task::spawn_named;
use util::vec::byte_swap;
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
})
}
/// In this function the gl commands are called.
/// Those messages that just involve a gl call have the call inlined,
/// processing of messages that require extra work are moved to functions
///
/// NB: Not gl-related validations (names, lengths, accepted parameters...) are
/// done in the corresponding DOM interfaces
pub fn handle_webgl_message(&self, message: CanvasWebGLMsg) {
match message {
CanvasWebGLMsg::GetContextAttributes(sender) =>
self.context_attributes(sender),
CanvasWebGLMsg::ActiveTexture(target) =>
gl::active_texture(target),
CanvasWebGLMsg::BlendColor(r, g, b, a) =>
gl::blend_color(r, g, b, a),
CanvasWebGLMsg::BlendEquation(mode) =>
gl::blend_equation(mode),
CanvasWebGLMsg::BlendEquationSeparate(mode_rgb, mode_alpha) =>
gl::blend_equation_separate(mode_rgb, mode_alpha),
CanvasWebGLMsg::BlendFunc(src, dest) =>
gl::blend_func(src, dest),
CanvasWebGLMsg::BlendFuncSeparate(src_rgb, dest_rgb, src_alpha, dest_alpha) =>
gl::blend_func_separate(src_rgb, dest_rgb, src_alpha, dest_alpha),
CanvasWebGLMsg::AttachShader(program_id, shader_id) =>
gl::attach_shader(program_id, shader_id),
CanvasWebGLMsg::BufferData(buffer_type, data, usage) =>
gl::buffer_data(buffer_type, &data, usage),
CanvasWebGLMsg::Clear(mask) =>
gl::clear(mask),
CanvasWebGLMsg::ClearColor(r, g, b, a) =>
gl::clear_color(r, g, b, a),
CanvasWebGLMsg::ClearDepth(depth) =>
gl::clear_depth(depth),
CanvasWebGLMsg::ClearStencil(stencil) =>
gl::clear_stencil(stencil),
CanvasWebGLMsg::ColorMask(r, g, b, a) =>
gl::color_mask(r, g, b, a),
CanvasWebGLMsg::CullFace(mode) =>
gl::cull_face(mode),
CanvasWebGLMsg::DepthFunc(func) =>
gl::depth_func(func),
CanvasWebGLMsg::DepthMask(flag) =>
gl::depth_mask(flag),
CanvasWebGLMsg::DepthRange(near, far) =>
gl::depth_range(near, far),
CanvasWebGLMsg::Disable(cap) =>
gl::disable(cap),
CanvasWebGLMsg::Enable(cap) =>
gl::enable(cap),
CanvasWebGLMsg::FrontFace(mode) =>
gl::front_face(mode),
CanvasWebGLMsg::DrawArrays(mode, first, count) =>
gl::draw_arrays(mode, first, count),
CanvasWebGLMsg::Hint(name, val) =>
gl::hint(name, val),
CanvasWebGLMsg::LineWidth(width) =>
gl::line_width(width),
CanvasWebGLMsg::PixelStorei(name, val) =>
gl::pixel_store_i(name, val),
CanvasWebGLMsg::PolygonOffset(factor, units) =>
gl::polygon_offset(factor, units),
CanvasWebGLMsg::EnableVertexAttribArray(attrib_id) =>
gl::enable_vertex_attrib_array(attrib_id),
CanvasWebGLMsg::GetAttribLocation(program_id, name, chan) =>
self.attrib_location(program_id, name, chan),
CanvasWebGLMsg::GetShaderParameter(shader_id, param_id, chan) =>
self.shader_parameter(shader_id, param_id, chan),
CanvasWebGLMsg::GetUniformLocation(program_id, name, chan) =>
self.uniform_location(program_id, name, chan),
CanvasWebGLMsg::CompileShader(shader_id, source) =>
self.compile_shader(shader_id, source),
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) =>
gl::delete_buffers(&[id]),
CanvasWebGLMsg::DeleteFramebuffer(id) =>
gl::delete_framebuffers(&[id]),
CanvasWebGLMsg::DeleteRenderbuffer(id) =>
gl::delete_renderbuffers(&[id]),
CanvasWebGLMsg::DeleteTexture(id) =>
gl::delete_textures(&[id]),
CanvasWebGLMsg::DeleteProgram(id) =>
gl::delete_program(id),
CanvasWebGLMsg::DeleteShader(id) =>
gl::delete_shader(id),
CanvasWebGLMsg::BindBuffer(target, id) =>
gl::bind_buffer(target, id),
CanvasWebGLMsg::BindFramebuffer(target, request) =>
self.bind_framebuffer(target, request),
CanvasWebGLMsg::BindRenderbuffer(target, id) =>
gl::bind_renderbuffer(target, id),
CanvasWebGLMsg::BindTexture(target, id) =>
gl::bind_texture(target, id),
CanvasWebGLMsg::LinkProgram(program_id) =>
gl::link_program(program_id),
CanvasWebGLMsg::Uniform4fv(uniform_id, data) =>
gl::uniform_4f(uniform_id, data[0], data[1], data[2], data[3]),
CanvasWebGLMsg::UseProgram(program_id) =>
gl::use_program(program_id),
CanvasWebGLMsg::VertexAttribPointer2f(attrib_id, size, normalized, stride, offset) =>
gl::vertex_attrib_pointer_f32(attrib_id, size, normalized, stride, offset as u32),
CanvasWebGLMsg::Viewport(x, y, width, height) =>
gl::viewport(x, y, width, height),
CanvasWebGLMsg::TexImage2D(target, level, internal, width, height, format, data_type, data) =>
gl::tex_image_2d(target, level, internal, width, height, /*border*/0, format, data_type, Some(&data)),
CanvasWebGLMsg::TexParameteri(target, name, value) =>
gl::tex_parameter_i(target, name, value),
CanvasWebGLMsg::TexParameterf(target, name, value) =>
gl::tex_parameter_f(target, name, value),
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 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()
}
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 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 compile_shader(&self, shader_id: u32, source: String) {
gl::shader_source(shader_id, &[source.as_bytes()]);
gl::compile_shader(shader_id);
}
fn 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 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 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();
}
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();
}
}