litehtml/containers/cairo/cairo_borders.cpp

348 lines
8.4 KiB
C++

#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()
{
int line_length = std::abs(bottom - top);
if(!line_length) return;
draw_line(border_width / 2.0,
top_border_width / 2.0,
bottom_border_width / 2.0);
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()
{
// Zero length line
if(bottom == top) return;
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);
}
}