Cargoify servo

components/gfx/render_context.rs

@@ -0,0 +1,419 @@
+/* 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 font_context::FontContext;
+use style::computed_values::border_style;
+
+use azure::azure_hl::{B8G8R8A8, A8, Color, ColorPattern, DrawOptions, DrawSurfaceOptions, DrawTarget};
+use azure::azure_hl::{Linear, SourceOp, StrokeOptions};
+use azure::AZ_CAP_BUTT;
+use azure::AzFloat;
+use geom::point::Point2D;
+use geom::rect::Rect;
+use geom::size::Size2D;
+use geom::side_offsets::SideOffsets2D;
+use libc::types::common::c99::uint16_t;
+use libc::size_t;
+use png::{RGB8, RGBA8, K8, KA8};
+use servo_net::image::base::Image;
+use servo_util::geometry::Au;
+use servo_util::opts::Opts;
+use sync::Arc;
+
+pub struct RenderContext<'a> {
+    pub draw_target: &'a DrawTarget,
+    pub font_ctx: &'a mut Box<FontContext>,
+    pub opts: &'a Opts,
+    /// The rectangle that this context encompasses in page coordinates.
+    pub page_rect: Rect<f32>,
+    /// The rectangle that this context encompasses in screen coordinates (pixels).
+    pub screen_rect: Rect<uint>,
+}
+
+enum Direction {
+    Top,
+    Left,
+    Right,
+    Bottom
+}
+
+enum DashSize {
+    DottedBorder = 1,
+    DashedBorder = 3
+}
+
+impl<'a> RenderContext<'a>  {
+    pub fn get_draw_target(&self) -> &'a DrawTarget {
+        self.draw_target
+    }
+
+    pub fn draw_solid_color(&self, bounds: &Rect<Au>, color: Color) {
+        self.draw_target.make_current();
+        self.draw_target.fill_rect(&bounds.to_azure_rect(), &ColorPattern::new(color), None);
+    }
+
+    pub fn draw_border(&self,
+                       bounds: &Rect<Au>,
+                       border: SideOffsets2D<Au>,
+                       color: SideOffsets2D<Color>,
+                       style: SideOffsets2D<border_style::T>) {
+        let border = border.to_float_px();
+        self.draw_target.make_current();
+
+        self.draw_border_segment(Top, bounds, border, color, style);
+        self.draw_border_segment(Right, bounds, border, color, style);
+        self.draw_border_segment(Bottom, bounds, border, color, style);
+        self.draw_border_segment(Left, bounds, border, color, style);
+    }
+
+    pub fn draw_line(&self,
+                     bounds: &Rect<Au>,
+                     color: Color,
+                     style: border_style::T) {
+        self.draw_target.make_current();
+
+        self.draw_line_segment(bounds, color, style);
+    }
+
+    pub fn draw_push_clip(&self, bounds: &Rect<Au>) {
+        let rect = bounds.to_azure_rect();
+        let path_builder = self.draw_target.create_path_builder();
+
+        let left_top = Point2D(rect.origin.x, rect.origin.y);
+        let right_top = Point2D(rect.origin.x + rect.size.width, rect.origin.y);
+        let left_bottom = Point2D(rect.origin.x, rect.origin.y + rect.size.height);
+        let right_bottom = Point2D(rect.origin.x + rect.size.width, rect.origin.y + rect.size.height);
+
+        path_builder.move_to(left_top);
+        path_builder.line_to(right_top);
+        path_builder.line_to(right_bottom);
+        path_builder.line_to(left_bottom);
+
+        let path = path_builder.finish();
+        self.draw_target.push_clip(&path);
+    }
+
+    pub fn draw_pop_clip(&self) {
+        self.draw_target.pop_clip();
+    }
+
+    pub fn draw_image(&self, bounds: Rect<Au>, image: Arc<Box<Image>>) {
+        let size = Size2D(image.width as i32, image.height as i32);
+        let (pixel_width, pixels, source_format) = match image.pixels {
+            RGBA8(ref pixels) => (4, pixels.as_slice(), B8G8R8A8),
+            K8(ref pixels) => (1, pixels.as_slice(), A8),
+            RGB8(_) => fail!("RGB8 color type not supported"),
+            KA8(_) => fail!("KA8 color type not supported"),
+        };
+        let stride = image.width * pixel_width;
+
+        self.draw_target.make_current();
+        let draw_target_ref = &self.draw_target;
+        let azure_surface = draw_target_ref.create_source_surface_from_data(pixels,
+                                                                            size,
+                                                                            stride as i32,
+                                                                            source_format);
+        let source_rect = Rect(Point2D(0u as AzFloat, 0u as AzFloat),
+                               Size2D(image.width as AzFloat, image.height as AzFloat));
+        let dest_rect = bounds.to_azure_rect();
+        let draw_surface_options = DrawSurfaceOptions::new(Linear, true);
+        let draw_options = DrawOptions::new(1.0f64 as AzFloat, 0);
+        draw_target_ref.draw_surface(azure_surface,
+                                     dest_rect,
+                                     source_rect,
+                                     draw_surface_options,
+                                     draw_options);
+    }
+
+    pub fn clear(&self) {
+        let pattern = ColorPattern::new(Color::new(0.0, 0.0, 0.0, 0.0));
+        let rect = Rect(Point2D(self.page_rect.origin.x as AzFloat,
+                                self.page_rect.origin.y as AzFloat),
+                        Size2D(self.screen_rect.size.width as AzFloat,
+                               self.screen_rect.size.height as AzFloat));
+        let mut draw_options = DrawOptions::new(1.0, 0);
+        draw_options.set_composition_op(SourceOp);
+        self.draw_target.make_current();
+        self.draw_target.fill_rect(&rect, &pattern, Some(&draw_options));
+    }
+
+    fn draw_border_segment(&self, direction: Direction, bounds: &Rect<Au>, border: SideOffsets2D<f32>, color: SideOffsets2D<Color>, style: SideOffsets2D<border_style::T>) {
+        let (style_select, color_select) = match direction {
+            Top => (style.top, color.top),
+            Left => (style.left, color.left),
+            Right => (style.right, color.right),
+            Bottom => (style.bottom, color.bottom)
+        };
+
+        match style_select{
+            border_style::none                         => {
+            }
+            border_style::hidden                       => {
+            }
+            //FIXME(sammykim): This doesn't work with dash_pattern and cap_style well. I referred firefox code.
+            border_style::dotted                       => {
+                self.draw_dashed_border_segment(direction, bounds, border, color_select, DottedBorder);
+            }
+            border_style::dashed                       => {
+                self.draw_dashed_border_segment(direction, bounds, border, color_select, DashedBorder);
+            }
+            border_style::solid                        => {
+                self.draw_solid_border_segment(direction,bounds,border,color_select);
+            }
+            border_style::double                       => {
+                self.draw_double_border_segment(direction, bounds, border, color_select);
+            }
+            border_style::groove | border_style::ridge => {
+                self.draw_groove_ridge_border_segment(direction, bounds, border, color_select, style_select);
+            }
+            border_style::inset | border_style::outset => {
+                self.draw_inset_outset_border_segment(direction, bounds, border, style_select, color_select);
+            }
+        }
+    }
+
+    fn draw_line_segment(&self, bounds: &Rect<Au>, color: Color, style: border_style::T) {
+        let border = SideOffsets2D::new_all_same(bounds.size.width).to_float_px();
+
+        match style{
+            border_style::none | border_style::hidden  => {}
+            border_style::dotted                       => {
+                self.draw_dashed_border_segment(Right, bounds, border, color, DottedBorder);
+            }
+            border_style::dashed                       => {
+                self.draw_dashed_border_segment(Right, bounds, border, color, DashedBorder);
+            }
+            border_style::solid                        => {
+                self.draw_solid_border_segment(Right,bounds,border,color);
+            }
+            border_style::double                       => {
+                self.draw_double_border_segment(Right, bounds, border, color);
+            }
+            border_style::groove | border_style::ridge => {
+                self.draw_groove_ridge_border_segment(Right, bounds, border, color, style);
+            }
+            border_style::inset | border_style::outset => {
+                self.draw_inset_outset_border_segment(Right, bounds, border, style, color);
+            }
+        }
+    }
+
+    fn draw_border_path(&self,
+                        bounds:    Rect<f32>,
+                        direction: Direction,
+                        border:    SideOffsets2D<f32>,
+                        color:     Color) {
+        let left_top     = bounds.origin;
+        let right_top    = left_top + Point2D(bounds.size.width, 0.0);
+        let left_bottom  = left_top + Point2D(0.0, bounds.size.height);
+        let right_bottom = left_top + Point2D(bounds.size.width, bounds.size.height);
+        let draw_opts    = DrawOptions::new(1.0, 0);
+        let path_builder = self.draw_target.create_path_builder();
+         match direction {
+             Top    => {
+                 path_builder.move_to(left_top);
+                 path_builder.line_to(right_top);
+                 path_builder.line_to(right_top + Point2D(-border.right, border.top));
+                 path_builder.line_to(left_top + Point2D(border.left, border.top));
+             }
+             Left   => {
+                 path_builder.move_to(left_top);
+                 path_builder.line_to(left_top + Point2D(border.left, border.top));
+                 path_builder.line_to(left_bottom + Point2D(border.left, -border.bottom));
+                 path_builder.line_to(left_bottom);
+             }
+             Right  => {
+                 path_builder.move_to(right_top);
+                 path_builder.line_to(right_bottom);
+                 path_builder.line_to(right_bottom + Point2D(-border.right, -border.bottom));
+                 path_builder.line_to(right_top + Point2D(-border.right, border.top));
+             }
+             Bottom => {
+                 path_builder.move_to(left_bottom);
+                 path_builder.line_to(left_bottom + Point2D(border.left, -border.bottom));
+                 path_builder.line_to(right_bottom + Point2D(-border.right, -border.bottom));
+                 path_builder.line_to(right_bottom);
+             }
+         }
+         let path = path_builder.finish();
+         self.draw_target.fill(&path, &ColorPattern::new(color), &draw_opts);
+
+     }
+
+    fn draw_dashed_border_segment(&self,
+                                  direction: Direction,
+                                  bounds:    &Rect<Au>,
+                                  border:    SideOffsets2D<f32>,
+                                  color:     Color,
+                                  dash_size: DashSize) {
+        let rect = bounds.to_azure_rect();
+        let draw_opts = DrawOptions::new(1u as AzFloat, 0 as uint16_t);
+        let mut stroke_opts = StrokeOptions::new(0u as AzFloat, 10u as AzFloat);
+        let mut dash: [AzFloat, ..2] = [0u as AzFloat, 0u as AzFloat];
+
+        stroke_opts.set_cap_style(AZ_CAP_BUTT as u8);
+
+        let border_width = match direction {
+            Top => border.top,
+            Left => border.left,
+            Right => border.right,
+            Bottom => border.bottom
+        };
+
+        stroke_opts.line_width = border_width;
+        dash[0] = border_width * (dash_size as int) as AzFloat;
+        dash[1] = border_width * (dash_size as int) as AzFloat;
+        stroke_opts.mDashPattern = dash.as_mut_ptr();
+        stroke_opts.mDashLength = dash.len() as size_t;
+
+        let (start, end)  = match direction {
+            Top => {
+                let y = rect.origin.y + border.top * 0.5;
+                let start = Point2D(rect.origin.x, y);
+                let end = Point2D(rect.origin.x + rect.size.width, y);
+                (start, end)
+            }
+            Left => {
+                let x = rect.origin.x + border.left * 0.5;
+                let start = Point2D(x, rect.origin.y + rect.size.height);
+                let end = Point2D(x, rect.origin.y + border.top);
+                (start, end)
+            }
+            Right => {
+                let x = rect.origin.x + rect.size.width - border.right * 0.5;
+                let start = Point2D(x, rect.origin.y);
+                let end = Point2D(x, rect.origin.y + rect.size.height);
+                (start, end)
+            }
+            Bottom => {
+                let y = rect.origin.y + rect.size.height - border.bottom * 0.5;
+                let start = Point2D(rect.origin.x + rect.size.width, y);
+                let end = Point2D(rect.origin.x + border.left, y);
+                (start, end)
+            }
+        };
+
+        self.draw_target.stroke_line(start,
+                                     end,
+                                     &ColorPattern::new(color),
+                                     &stroke_opts,
+                                     &draw_opts);
+    }
+
+    fn draw_solid_border_segment(&self, direction: Direction, bounds: &Rect<Au>, border: SideOffsets2D<f32>, color: Color) {
+        let rect = bounds.to_azure_rect();
+        self.draw_border_path(rect, direction, border, color);
+    }
+
+    fn get_scaled_bounds(&self,
+                         bounds:        &Rect<Au>,
+                         border:        SideOffsets2D<f32>,
+                         shrink_factor: f32) -> Rect<f32> {
+        let rect            = bounds.to_azure_rect();
+        let scaled_border   = SideOffsets2D::new(shrink_factor * border.top,
+                                                 shrink_factor * border.right,
+                                                 shrink_factor * border.bottom,
+                                                 shrink_factor * border.left);
+        let left_top        = Point2D(rect.origin.x, rect.origin.y);
+        let scaled_left_top = left_top + Point2D(scaled_border.left,
+                                                 scaled_border.top);
+        return Rect(scaled_left_top,
+                    Size2D(rect.size.width - 2.0 * scaled_border.right, rect.size.height - 2.0 * scaled_border.bottom));
+    }
+
+    fn scale_color(&self, color: Color, scale_factor: f32) -> Color {
+        return Color::new(color.r * scale_factor, color.g * scale_factor, color.b * scale_factor, color.a);
+    }
+
+    fn draw_double_border_segment(&self, direction: Direction, bounds: &Rect<Au>, border: SideOffsets2D<f32>, color: Color) {
+        let scaled_border       = SideOffsets2D::new((1.0/3.0) * border.top,
+                                                     (1.0/3.0) * border.right,
+                                                     (1.0/3.0) * border.bottom,
+                                                     (1.0/3.0) * border.left);
+        let inner_scaled_bounds = self.get_scaled_bounds(bounds, border, 2.0/3.0);
+        // draw the outer portion of the double border.
+        self.draw_solid_border_segment(direction, bounds, scaled_border, color);
+        // draw the inner portion of the double border.
+        self.draw_border_path(inner_scaled_bounds, direction, scaled_border, color);
+    }
+
+    fn draw_groove_ridge_border_segment(&self,
+                                        direction: Direction,
+                                        bounds:    &Rect<Au>,
+                                        border:    SideOffsets2D<f32>,
+                                        color:     Color,
+                                        style:     border_style::T) {
+        // original bounds as a Rect<f32>, with no scaling.
+        let original_bounds            = self.get_scaled_bounds(bounds, border, 0.0);
+        // shrink the bounds by 1/2 of the border, leaving the innermost 1/2 of the border
+        let inner_scaled_bounds        = self.get_scaled_bounds(bounds, border, 0.5);
+        let scaled_border              = SideOffsets2D::new(0.5 * border.top,
+                                                            0.5 * border.right,
+                                                            0.5 * border.bottom,
+                                                            0.5 * border.left);
+        let is_groove = match style {
+                border_style::groove =>  true,
+                border_style::ridge  =>  false,
+                _                    =>  fail!("invalid border style")
+        };
+        let darker_color               = self.scale_color(color, if is_groove { 1.0/3.0 } else { 2.0/3.0 });
+        let (outer_color, inner_color) = match (direction, is_groove) {
+            (Top, true)  | (Left, true)  | (Right, false) | (Bottom, false) => (darker_color, color),
+            (Top, false) | (Left, false) | (Right, true)  | (Bottom, true)  => (color, darker_color)
+        };
+        // outer portion of the border
+        self.draw_border_path(original_bounds, direction, scaled_border, outer_color);
+        // inner portion of the border
+        self.draw_border_path(inner_scaled_bounds, direction, scaled_border, inner_color);
+    }
+
+    fn draw_inset_outset_border_segment(&self,
+                                        direction: Direction,
+                                        bounds:    &Rect<Au>,
+                                        border:    SideOffsets2D<f32>,
+                                        style:     border_style::T,
+                                        color:     Color) {
+        let is_inset = match style {
+                border_style::inset  =>  true,
+                border_style::outset =>  false,
+                _                    =>  fail!("invalid border style")
+        };
+        // original bounds as a Rect<f32>
+        let original_bounds = self.get_scaled_bounds(bounds, border, 0.0);
+        // select and scale the color appropriately.
+        let scaled_color    = match direction {
+            Top             => self.scale_color(color, if is_inset { 2.0/3.0 } else { 1.0     }),
+            Left            => self.scale_color(color, if is_inset { 1.0/6.0 } else { 0.5     }),
+            Right | Bottom  => self.scale_color(color, if is_inset { 1.0     } else { 2.0/3.0 })
+        };
+        self.draw_border_path(original_bounds, direction, border, scaled_color);
+    }
+
+}
+
+trait ToAzureRect {
+    fn to_azure_rect(&self) -> Rect<AzFloat>;
+}
+
+impl ToAzureRect for Rect<Au> {
+    fn to_azure_rect(&self) -> Rect<AzFloat> {
+        Rect(Point2D(self.origin.x.to_nearest_px() as AzFloat,
+                     self.origin.y.to_nearest_px() as AzFloat),
+             Size2D(self.size.width.to_nearest_px() as AzFloat,
+                    self.size.height.to_nearest_px() as AzFloat))
+    }
+}
+
+trait ToSideOffsetsPx {
+    fn to_float_px(&self) -> SideOffsets2D<AzFloat>;
+}
+
+impl ToSideOffsetsPx for SideOffsets2D<Au> {
+    fn to_float_px(&self) -> SideOffsets2D<AzFloat> {
+        SideOffsets2D::new(self.top.to_nearest_px() as AzFloat,
+                           self.right.to_nearest_px() as AzFloat,
+                           self.bottom.to_nearest_px() as AzFloat,
+                           self.left.to_nearest_px() as AzFloat)
+    }
+}