litehtml - lightweight html renderer

1 files changed, 342 insertions, 0 deletions

diff --git a/libs/litehtml/containers/cairo/cairo_borders.cpp b/libs/litehtml/containers/cairo/cairo_borders.cpp
new file mode 100644
index 0000000000..21ae6db4cd
--- /dev/null
+++ b/libs/litehtml/containers/cairo/cairo_borders.cpp
@@ -0,0 +1,342 @@
+#include <litehtml.h>
+#include "cairo_borders.h"
+#include <cmath>
+
+#ifndef M_PI
+#       define M_PI    3.14159265358979323846
+#endif
+
+void cairo::add_path_arc(cairo_t* cr, double x, double y, double rx, double ry, double a1, double a2, bool neg)
+{
+	if(rx > 0 && ry > 0)
+	{
+		cairo_save(cr);
+
+		cairo_translate(cr, x, y);
+		cairo_scale(cr, 1, ry / rx);
+		cairo_translate(cr, -x, -y);
+
+		if(neg)
+		{
+			cairo_arc_negative(cr, x, y, rx, a1, a2);
+		} else
+		{
+			cairo_arc(cr, x, y, rx, a1, a2);
+		}
+
+		cairo_restore(cr);
+	} else
+	{
+		cairo_move_to(cr, x, y);
+	}
+}
+
+/**
+ * Draw border at the left side. Use the only function to draw all border by using rotation transfer
+ * @param cr cairo context
+ * @param left left position of the border
+ * @param top top position of the border
+ * @param bottom bottom position of the border
+ * @param data border data
+ */
+void cairo::border::draw_border()
+{
+	cairo_save(cr);
+
+	if(radius_top_x && radius_top_y)
+	{
+		double start_angle	= M_PI;
+		double end_angle	= start_angle + M_PI / 2.0  / ((double) top_border_width / (double) border_width + 1);
+
+		add_path_arc(cr,
+					 left + radius_top_x,
+					 top + radius_top_y,
+					 radius_top_x - border_width,
+					 radius_top_y - border_width + (border_width - top_border_width),
+					 start_angle,
+					 end_angle, false);
+
+		add_path_arc(cr,
+					 left + radius_top_x,
+					 top + radius_top_y,
+					 radius_top_x,
+					 radius_top_y,
+					 end_angle,
+					 start_angle, true);
+	} else
+	{
+		cairo_move_to(cr, left + border_width, top + top_border_width);
+		cairo_line_to(cr, left, top);
+	}
+
+	if(radius_bottom_x && radius_bottom_y)
+	{
+		cairo_line_to(cr, left, bottom - radius_bottom_y);
+
+		double end_angle	= M_PI;
+		double start_angle	= end_angle - M_PI / 2.0  / ((double) bottom_border_width / (double) border_width + 1);
+
+		add_path_arc(cr,
+					 left + radius_bottom_x,
+					 bottom - radius_bottom_y,
+					 radius_bottom_x,
+					 radius_bottom_y,
+					 end_angle,
+					 start_angle, true);
+
+		add_path_arc(cr,
+					 left + radius_bottom_x,
+					 bottom - radius_bottom_y,
+					 radius_bottom_x - border_width,
+					 radius_bottom_y - border_width + (border_width - bottom_border_width),
+					 start_angle,
+					 end_angle, false);
+	} else
+	{
+		cairo_line_to(cr, left,	bottom);
+		cairo_line_to(cr, left + border_width, bottom - bottom_border_width);
+	}
+	cairo_clip(cr);
+
+	switch (style)
+	{
+		case litehtml::border_style_dotted:
+			draw_dotted();
+			break;
+		case litehtml::border_style_dashed:
+			draw_dashed();
+			break;
+		case litehtml::border_style_double:
+			draw_double();
+			break;
+		case litehtml::border_style_inset:
+			draw_inset_outset(true);
+			break;
+		case litehtml::border_style_outset:
+			draw_inset_outset(false);
+			break;
+		case litehtml::border_style_groove:
+			draw_groove_ridge(true);
+			break;
+		case litehtml::border_style_ridge:
+			draw_groove_ridge(false);
+			break;
+		default:
+			draw_solid();
+			break;
+	}
+
+	cairo_restore(cr);
+}
+
+void cairo::border::draw_line(double line_offset, double top_line_offset, double bottom_line_offset)
+{
+	if(radius_top_x && radius_top_y)
+	{
+		double end_angle = M_PI;
+		double start_angle	= end_angle + M_PI / 2.0  / ((double) top_border_width / (double) border_width + 1);
+
+		add_path_arc(cr,
+					 left + radius_top_x,
+					 top + radius_top_y,
+					 radius_top_x - line_offset,
+					 radius_top_y - line_offset + (line_offset - top_line_offset),
+					 start_angle,
+					 end_angle, true);
+	} else
+	{
+		cairo_move_to(cr, left + line_offset, top);
+	}
+
+	if(radius_bottom_x && radius_bottom_y)
+	{
+		cairo_line_to(cr, left + line_offset, bottom - radius_bottom_y);
+
+		double start_angle	= M_PI;
+		double end_angle	= start_angle - M_PI / 2.0  / ((double) bottom_border_width / (double) border_width + 1);
+
+		add_path_arc(cr,
+					 left + radius_bottom_x,
+					 bottom - radius_bottom_y,
+					 radius_bottom_x - line_offset,
+					 radius_bottom_y - line_offset + (line_offset - bottom_line_offset),
+					 start_angle,
+					 end_angle, true);
+	} else
+	{
+		cairo_line_to(cr, left + line_offset, bottom);
+	}
+}
+
+void cairo::border::draw_inset_outset(bool is_inset)
+{
+	litehtml::web_color line_color;
+	litehtml::web_color light_color = color;
+	litehtml::web_color dark_color = color.darken(0.33);
+	if(color.red == 0 && color.green == 0 && color.blue == 0)
+	{
+		dark_color.red = dark_color.green = dark_color.blue = 0x4C;
+		light_color.red = light_color.green = light_color.blue = 0xB2;
+	}
+
+	if (real_side == left_side || real_side == top_side)
+	{
+		line_color = is_inset ? dark_color : light_color;
+	} else
+	{
+		line_color = is_inset ? light_color : dark_color;
+	}
+	draw_line(border_width / 2.0,
+			  top_border_width / 2.0,
+			  bottom_border_width / 2.0);
+	cairo_set_line_cap(cr, CAIRO_LINE_CAP_BUTT);
+	cairo_set_dash(cr, nullptr, 0, 0);
+	set_color(cr, line_color);
+	cairo_set_line_width(cr, border_width);
+	cairo_stroke(cr);
+}
+
+void cairo::border::draw_double()
+{
+	if (border_width < 3)
+	{
+		draw_solid();
+	} else
+	{
+		cairo_set_line_cap(cr, CAIRO_LINE_CAP_BUTT);
+		cairo_set_dash(cr, nullptr, 0, 0);
+		set_color(cr, color);
+
+		double line_width = border_width / 3.0;
+		cairo_set_line_width(cr, line_width);
+		// draw external line
+		draw_line(line_width / 2.0,
+				  top_border_width / 6.0,
+				  bottom_border_width / 6.0);
+		cairo_stroke(cr);
+		// draw internal line
+		draw_line(border_width - line_width / 2.0,
+				  top_border_width - top_border_width / 6.0,
+				  bottom_border_width - bottom_border_width / 6.0);
+		cairo_stroke(cr);
+	}
+}
+
+void cairo::border::draw_dashed()
+{
+	draw_line(border_width / 2.0,
+			  top_border_width / 2.0,
+			  bottom_border_width / 2.0);
+
+	int line_length = std::abs(bottom - top);
+	int segment_length = border_width * 3;
+	int seg_nums = line_length / segment_length;
+	if(seg_nums < 2)
+	{
+		seg_nums = 2;
+	} if(seg_nums % 2 != 0)
+	{
+		seg_nums = seg_nums + 1;
+	}
+	seg_nums++;
+	double seg_len = (double) line_length / (double) seg_nums;
+
+	double dashes[2];
+	dashes[0] = seg_len;
+	dashes[1] = seg_len;
+	cairo_set_line_cap(cr, CAIRO_LINE_CAP_BUTT);
+	cairo_set_dash(cr, dashes, 2, 0);
+	set_color(cr, color);
+	cairo_set_line_width(cr, border_width);
+	cairo_stroke(cr);
+}
+
+void cairo::border::draw_solid()
+{
+	draw_line(border_width / 2.0,
+			  top_border_width / 2.0,
+			  bottom_border_width / 2.0);
+	cairo_set_line_cap(cr, CAIRO_LINE_CAP_BUTT);
+	cairo_set_dash(cr, nullptr, 0, 0);
+	set_color(cr, color);
+	cairo_set_line_width(cr, border_width);
+	cairo_stroke(cr);
+}
+
+void cairo::border::draw_dotted()
+{
+	draw_line(border_width / 2.0,
+			  top_border_width / 2.0,
+			  bottom_border_width / 2.0);
+
+	double line_length = std::abs(bottom - top);
+
+	double dot_size = border_width;
+	int num_dots = (int) std::nearbyint(line_length / (dot_size * 2.0));
+	if(num_dots < 2)
+	{
+		num_dots = 2;
+	} if(num_dots % 2 != 0)
+	{
+		num_dots = num_dots + 1;
+	}
+	num_dots++;
+	double space_len = ((double) line_length - (double) border_width) / (num_dots - 1.0);
+
+	double dashes[2];
+	dashes[0] = 0;
+	dashes[1] = space_len;
+	cairo_set_line_cap(cr, CAIRO_LINE_CAP_ROUND);
+	cairo_set_dash(cr, dashes, 2, -dot_size / 2.0);
+
+	set_color(cr, color);
+	cairo_set_line_width(cr, border_width);
+	cairo_stroke(cr);
+}
+
+void cairo::border::draw_groove_ridge(bool is_groove)
+{
+	if(border_width == 1)
+	{
+		draw_solid();
+	} else
+	{
+		litehtml::web_color inner_line_color;
+		litehtml::web_color outer_line_color;
+		litehtml::web_color light_color = color;
+		litehtml::web_color dark_color = color.darken(0.33);
+		if (color.red == 0 && color.green == 0 && color.blue == 0)
+		{
+			dark_color.red = dark_color.green = dark_color.blue = 0x4C;
+			light_color.red = light_color.green = light_color.blue = 0xB2;
+		}
+
+		if (real_side == left_side || real_side == top_side)
+		{
+			outer_line_color = is_groove ? dark_color : light_color;
+			inner_line_color = is_groove ? light_color : dark_color;
+		} else
+		{
+			outer_line_color = is_groove ? light_color : dark_color;
+			inner_line_color = is_groove ? dark_color : light_color;
+		}
+
+		cairo_set_line_cap(cr, CAIRO_LINE_CAP_BUTT);
+		cairo_set_dash(cr, nullptr, 0, 0);
+
+		double line_width = border_width / 2.0;
+		cairo_set_line_width(cr, line_width);
+		// draw external line
+		draw_line(line_width / 2.0,
+				  top_border_width / 4.0,
+				  bottom_border_width / 4.0);
+		set_color(cr, outer_line_color);
+		cairo_stroke(cr);
+		// draw internal line
+		set_color(cr, inner_line_color);
+		draw_line(border_width - line_width / 2.0,
+				  top_border_width - top_border_width / 4.0,
+				  bottom_border_width - bottom_border_width / 4.0);
+		cairo_stroke(cr);
+	}
+}