Add a Pango renderer

Copy the PangoCairoRenderer into GTK+, rename it to GskPangoRenderer,
and strip it down far enough to build without private pango apis.
This means we currently don't support hexboxes or shapes.

Currently, this lives in gtk, but it might be nicer to put it
in gsk eventually.
This commit is contained in:
Matthias Clasen 2017-08-30 11:12:50 -04:00
parent 3fc1cafec0
commit 82e8f3a542
3 changed files with 577 additions and 0 deletions

531
gtk/gskpango.c Normal file
View File

@ -0,0 +1,531 @@
/*
* Copyright (C) 2017 Red Hat, Inc.
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Library General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Library General Public License for more details.
*
* You should have received a copy of the GNU Library General Public
* License along with this library; if not, write to the
* Free Software Foundation, Inc., 59 Temple Place - Suite 330,
* Boston, MA 02111-1307, USA.
*/
#include "config.h"
#include "gsk/gsk.h"
#include "gskpango.h"
#include <math.h>
#include <pango/pango.h>
#include <cairo/cairo.h>
#define GSK_PANGO_RENDERER_CLASS(klass) (G_TYPE_CHECK_CLASS_CAST ((klass), GSK_TYPE_PANGO_RENDERER, GskPangoRendererClass))
#define GSK_IS_PANGO_RENDERER_CLASS(klass) (G_TYPE_CHECK_CLASS_TYPE ((klass), GSK_TYPE_PANGO_RENDERER))
#define GSK_PANGO_RENDERER_GET_CLASS(obj) (G_TYPE_INSTANCE_GET_CLASS ((obj), GSK_TYPE_PANGO_RENDERER, GskPangoRendererClass))
/*
* This is a PangoRenderer implementation that translates all the draw calls to
* gsk render nodes, using the GtkSnapshot helper class. Glyphs are translated
* to text nodes, all other draw calls fall back to cairo nodes.
*/
struct _GskPangoRenderer
{
PangoRenderer parent_instance;
GtkSnapshot *snapshot;
GdkRGBA fg_color;
graphene_rect_t bounds;
/* house-keeping options */
gboolean is_cached_renderer;
};
struct _GskPangoRendererClass
{
PangoRendererClass parent_class;
};
G_DEFINE_TYPE (GskPangoRenderer, gsk_pango_renderer, PANGO_TYPE_RENDERER)
static void
get_color (GskPangoRenderer *crenderer,
PangoRenderPart part,
GdkRGBA *rgba)
{
PangoColor *color = pango_renderer_get_color ((PangoRenderer *) (crenderer), part);
guint16 a = pango_renderer_get_alpha ((PangoRenderer *) (crenderer), part);
gdouble red, green, blue, alpha;
red = crenderer->fg_color.red;
green = crenderer->fg_color.green;
blue = crenderer->fg_color.blue;
alpha = crenderer->fg_color.alpha;
if (color)
{
red = color->red / 65535.;
green = color->green / 65535.;
blue = color->blue / 65535.;
alpha = 1.;
}
if (a)
alpha = a / 65535.;
rgba->red = red;
rgba->green = green;
rgba->blue = blue;
rgba->alpha = alpha;
}
static void
set_color (GskPangoRenderer *crenderer,
PangoRenderPart part,
cairo_t *cr)
{
GdkRGBA rgba = { 0, 0, 0, 1 };
get_color (crenderer, part, &rgba);
gdk_cairo_set_source_rgba (cr, &rgba);
}
static gboolean
_pango_cairo_font_install (PangoFont *font,
cairo_t *cr)
{
cairo_scaled_font_t *scaled_font = pango_cairo_font_get_scaled_font ((PangoCairoFont *)font);
if (G_UNLIKELY (scaled_font == NULL || cairo_scaled_font_status (scaled_font) != CAIRO_STATUS_SUCCESS))
return FALSE;
cairo_set_scaled_font (cr, scaled_font);
return TRUE;
}
static void
gsk_pango_renderer_draw_unknown_glyph (GskPangoRenderer *crenderer,
PangoFont *font,
PangoGlyphInfo *gi,
double cx,
double cy)
{
cairo_t *cr;
PangoGlyphString *glyphs;
cr = gtk_snapshot_append_cairo (crenderer->snapshot, &crenderer->bounds, "DrawUnknownGlyph<%u>", gi->glyph);
gdk_cairo_set_source_rgba (cr, &crenderer->fg_color);
cairo_move_to (cr, cx, cy);
glyphs = pango_glyph_string_new ();
pango_glyph_string_set_size (glyphs, 1);
glyphs->glyphs[0] = *gi;
pango_cairo_show_glyph_string (cr, font, glyphs);
cairo_destroy (cr);
}
#ifndef STACK_BUFFER_SIZE
#define STACK_BUFFER_SIZE (512 * sizeof (int))
#endif
#define STACK_ARRAY_LENGTH(T) (STACK_BUFFER_SIZE / sizeof(T))
static void
gsk_pango_renderer_show_text_glyphs (PangoRenderer *renderer,
const char *text,
int text_len,
PangoGlyphString *glyphs,
cairo_text_cluster_t *clusters,
int num_clusters,
gboolean backward,
PangoFont *font,
int x,
int y)
{
GskPangoRenderer *crenderer = (GskPangoRenderer *) (renderer);
cairo_t *cr;
int i, count;
int x_position = 0;
cairo_glyph_t *cairo_glyphs;
cairo_glyph_t stack_glyphs[STACK_ARRAY_LENGTH (cairo_glyph_t)];
double base_x = crenderer->x_offset + (double)x / PANGO_SCALE;
double base_y = crenderer->y_offset + (double)y / PANGO_SCALE;
cr = gtk_snapshot_append_cairo (crenderer->snapshot, &crenderer->bounds, "Text<%dglyphs>", glyphs->num_glyphs);
set_color (crenderer, PANGO_RENDER_PART_FOREGROUND, cr);
if (!_pango_cairo_font_install (font, cr))
{
for (i = 0; i < glyphs->num_glyphs; i++)
{
PangoGlyphInfo *gi = &glyphs->glyphs[i];
if (gi->glyph != PANGO_GLYPH_EMPTY)
{
double cx = base_x + (double)(x_position + gi->geometry.x_offset) / PANGO_SCALE;
double cy = gi->geometry.y_offset == 0 ?
base_y :
base_y + (double)(gi->geometry.y_offset) / PANGO_SCALE;
gsk_pango_renderer_draw_unknown_glyph (crenderer, font, gi, cx, cy);
}
x_position += gi->geometry.width;
}
goto done;
}
if (glyphs->num_glyphs > (int) G_N_ELEMENTS (stack_glyphs))
cairo_glyphs = g_new (cairo_glyph_t, glyphs->num_glyphs);
else
cairo_glyphs = stack_glyphs;
count = 0;
for (i = 0; i < glyphs->num_glyphs; i++)
{
PangoGlyphInfo *gi = &glyphs->glyphs[i];
if (gi->glyph != PANGO_GLYPH_EMPTY)
{
double cx = base_x + (double)(x_position + gi->geometry.x_offset) / PANGO_SCALE;
double cy = gi->geometry.y_offset == 0 ?
base_y :
base_y + (double)(gi->geometry.y_offset) / PANGO_SCALE;
if (gi->glyph & PANGO_GLYPH_UNKNOWN_FLAG)
gsk_pango_renderer_draw_unknown_glyph (crenderer, font, gi, cx, cy);
else
{
cairo_glyphs[count].index = gi->glyph;
cairo_glyphs[count].x = cx;
cairo_glyphs[count].y = cy;
count++;
}
}
x_position += gi->geometry.width;
}
if (G_UNLIKELY (clusters))
cairo_show_text_glyphs (cr,
text, text_len,
cairo_glyphs, count,
clusters, num_clusters,
backward ? CAIRO_TEXT_CLUSTER_FLAG_BACKWARD : 0);
else
cairo_show_glyphs (cr, cairo_glyphs, count);
if (cairo_glyphs != stack_glyphs)
g_free (cairo_glyphs);
done:
cairo_destroy (cr);
}
static void
gsk_pango_renderer_draw_glyphs (PangoRenderer *renderer,
PangoFont *font,
PangoGlyphString *glyphs,
int x,
int y)
{
gsk_pango_renderer_show_text_glyphs (renderer, NULL, 0, glyphs, NULL, 0, FALSE, font, x, y);
}
static void
gsk_pango_renderer_draw_glyph_item (PangoRenderer *renderer,
const char *text,
PangoGlyphItem *glyph_item,
int x,
int y)
{
PangoFont *font = glyph_item->item->analysis.font;
PangoGlyphString *glyphs = glyph_item->glyphs;
gsk_pango_renderer_show_text_glyphs (renderer, NULL, 0, glyphs, NULL, 0, FALSE, font, x, y);
}
static void
gsk_pango_renderer_draw_rectangle (PangoRenderer *renderer,
PangoRenderPart part,
int x,
int y,
int width,
int height)
{
GskPangoRenderer *crenderer = (GskPangoRenderer *) (renderer);
GdkRGBA rgba;
graphene_rect_t bounds;
get_color (crenderer, part, &rgba);
graphene_rect_init (&bounds,
(double)x / PANGO_SCALE, (double)y / PANGO_SCALE,
(double)width / PANGO_SCALE, (double)height / PANGO_SCALE);
gtk_snapshot_append_color (crenderer->snapshot, &rgba, &bounds, "DrawRectangle");
}
static void
gsk_pango_renderer_draw_trapezoid (PangoRenderer *renderer,
PangoRenderPart part,
double y1_,
double x11,
double x21,
double y2,
double x12,
double x22)
{
GskPangoRenderer *crenderer = (GskPangoRenderer *) (renderer);
cairo_t *cr;
gdouble x, y;
cr = gtk_snapshot_append_cairo (crenderer->snapshot, &crenderer->bounds, "DrawTrapezoid");
set_color (crenderer, part, cr);
x = y = 0;
cairo_user_to_device_distance (cr, &x, &y);
cairo_identity_matrix (cr);
cairo_translate (cr, x, y);
cairo_move_to (cr, x11, y1_);
cairo_line_to (cr, x21, y1_);
cairo_line_to (cr, x22, y2);
cairo_line_to (cr, x12, y2);
cairo_close_path (cr);
cairo_fill (cr);
cairo_destroy (cr);
}
/* Draws an error underline that looks like one of:
* H E H
* /\ /\ /\ /\ /\ -
* A/ \ / \ / \ A/ \ / \ |
* \ \ / \ / /D \ \ / \ |
* \ \/ C \/ / \ \/ C \ | height = HEIGHT_SQUARES * square
* \ /\ F / \ F /\ \ |
* \ / \ / \ / \ \G |
* \ / \ / \ / \ / |
* \/ \/ \/ \/ -
* B B
* |---|
* unit_width = (HEIGHT_SQUARES - 1) * square
*
* The x, y, width, height passed in give the desired bounding box;
* x/width are adjusted to make the underline a integer number of units
* wide.
*/
#define HEIGHT_SQUARES 2.5
static void
draw_error_underline (cairo_t *cr,
double x,
double y,
double width,
double height)
{
double square = height / HEIGHT_SQUARES;
double unit_width = (HEIGHT_SQUARES - 1) * square;
double double_width = 2 * unit_width;
int width_units = (width + unit_width / 2) / unit_width;
double y_top, y_bottom;
double x_left, x_middle, x_right;
int i;
x += (width - width_units * unit_width) / 2;
y_top = y;
y_bottom = y + height;
/* Bottom of squiggle */
x_middle = x + unit_width;
x_right = x + double_width;
cairo_move_to (cr, x - square / 2, y_top + square / 2); /* A */
for (i = 0; i < width_units-2; i += 2)
{
cairo_line_to (cr, x_middle, y_bottom); /* B */
cairo_line_to (cr, x_right, y_top + square); /* C */
x_middle += double_width;
x_right += double_width;
}
cairo_line_to (cr, x_middle, y_bottom); /* B */
if (i + 1 == width_units)
cairo_line_to (cr, x_middle + square / 2, y_bottom - square / 2); /* G */
else if (i + 2 == width_units) {
cairo_line_to (cr, x_right + square / 2, y_top + square / 2); /* D */
cairo_line_to (cr, x_right, y_top); /* E */
}
/* Top of squiggle */
x_left = x_middle - unit_width;
for (; i >= 0; i -= 2)
{
cairo_line_to (cr, x_middle, y_bottom - square); /* F */
cairo_line_to (cr, x_left, y_top); /* H */
x_left -= double_width;
x_middle -= double_width;
}
}
static void
gsk_pango_renderer_draw_error_underline (PangoRenderer *renderer,
int x,
int y,
int width,
int height)
{
GskPangoRenderer *crenderer = (GskPangoRenderer *) (renderer);
cairo_t *cr;
cr = gtk_snapshot_append_cairo (crenderer->snapshot, &crenderer->bounds, "DrawTrapezoid");
set_color (crenderer, PANGO_RENDER_PART_UNDERLINE, cr);
cairo_new_path (cr);
draw_error_underline (cr,
(double)x / PANGO_SCALE, (double)y / PANGO_SCALE,
(double)width / PANGO_SCALE, (double)height / PANGO_SCALE);
cairo_fill (cr);
cairo_destroy (cr);
}
static void
gsk_pango_renderer_draw_shape (PangoRenderer *renderer,
PangoAttrShape *attr,
int x,
int y)
{
GskPangoRenderer *crenderer = (GskPangoRenderer *) (renderer);
cairo_t *cr;
PangoLayout *layout;
PangoCairoShapeRendererFunc shape_renderer;
gpointer shape_renderer_data;
double base_x = (double)x / PANGO_SCALE;
double base_y = (double)y / PANGO_SCALE;
cr = gtk_snapshot_append_cairo (crenderer->snapshot, &crenderer->bounds, "DrawShape");
layout = pango_renderer_get_layout (renderer);
if (!layout)
return;
shape_renderer = pango_cairo_context_get_shape_renderer (pango_layout_get_context (layout),
&shape_renderer_data);
if (!shape_renderer)
return;
set_color (crenderer, PANGO_RENDER_PART_FOREGROUND, cr);
cairo_move_to (cr, base_x, base_y);
shape_renderer (cr, attr, FALSE, shape_renderer_data);
cairo_destroy (cr);
}
static void
gsk_pango_renderer_init (GskPangoRenderer *renderer G_GNUC_UNUSED)
{
}
static void
gsk_pango_renderer_class_init (GskPangoRendererClass *klass)
{
PangoRendererClass *renderer_class = PANGO_RENDERER_CLASS (klass);
renderer_class->draw_glyphs = gsk_pango_renderer_draw_glyphs;
renderer_class->draw_glyph_item = gsk_pango_renderer_draw_glyph_item;
renderer_class->draw_rectangle = gsk_pango_renderer_draw_rectangle;
renderer_class->draw_trapezoid = gsk_pango_renderer_draw_trapezoid;
renderer_class->draw_error_underline = gsk_pango_renderer_draw_error_underline;
renderer_class->draw_shape = gsk_pango_renderer_draw_shape;
}
static GskPangoRenderer *cached_renderer = NULL; /* MT-safe */
G_LOCK_DEFINE_STATIC (cached_renderer);
static GskPangoRenderer *
acquire_renderer (void)
{
GskPangoRenderer *renderer;
if (G_LIKELY (G_TRYLOCK (cached_renderer)))
{
if (G_UNLIKELY (!cached_renderer))
{
cached_renderer = g_object_new (GSK_TYPE_PANGO_RENDERER, NULL);
cached_renderer->is_cached_renderer = TRUE;
}
renderer = cached_renderer;
}
else
{
renderer = g_object_new (GSK_TYPE_PANGO_RENDERER, NULL);
}
return renderer;
}
static void
release_renderer (GskPangoRenderer *renderer)
{
if (G_LIKELY (renderer->is_cached_renderer))
{
renderer->snapshot = NULL;
G_UNLOCK (cached_renderer);
}
else
g_object_unref (renderer);
}
/* convenience wrappers using the default renderer */
void
gsk_pango_show_layout (GtkSnapshot *snapshot,
const GdkRGBA *fg_color,
PangoLayout *layout)
{
GskPangoRenderer *crenderer;
PangoRectangle ink_rect;
g_return_if_fail (snapshot != NULL);
g_return_if_fail (PANGO_IS_LAYOUT (layout));
crenderer = acquire_renderer ();
crenderer->snapshot = snapshot;
crenderer->fg_color = *fg_color;
pango_layout_get_pixel_extents (layout, &ink_rect, NULL);
graphene_rect_init (&crenderer->bounds, ink_rect.x, ink_rect.y, ink_rect.width, ink_rect.height);
pango_renderer_draw_layout (PANGO_RENDERER (crenderer), layout, 0, 0);
release_renderer (crenderer);
}

45
gtk/gskpango.h Normal file
View File

@ -0,0 +1,45 @@
/* GSK - The GTK Scene Kit
*
* Copyright 2017 Red Hat, Inc.
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library. If not, see <http://www.gnu.org/licenses/>.
*/
#ifndef __GSK_PANGO_H__
#define __GSK_PANGO_H__
#include <pango/pango.h>
#include "gtk/gtksnapshot.h"
G_BEGIN_DECLS
#define GSK_TYPE_PANGO_RENDERER (gsk_pango_renderer_get_type ())
#define GSK_PANGO_RENDERER(obj) (G_TYPE_CHECK_INSTANCE_CAST ((obj), GSK_TYPE_PANGO_RENDERER, GskPangoRenderer))
#define GSK_IS_PANGO_RENDERER(obj) (G_TYPE_CHECK_INSTANCE_TYPE ((obj), GSK_TYPE_PANGO_RENDERER))
typedef struct _GskPangoRenderer GskPangoRenderer;
typedef struct _GskPangoRendererClass GskPangoRendererClass;
GDK_AVAILABLE_IN_3_92
GType gsk_pango_renderer_get_type (void) G_GNUC_CONST;
GDK_AVAILABLE_IN_3_92
void gsk_pango_show_layout (GtkSnapshot *snapshot,
const GdkRGBA *fg_color,
PangoLayout *layout);
G_END_DECLS
#endif /* __GSK_PANGO_H__ */

View File

@ -231,6 +231,7 @@ gtk_public_sources = files([
'gtkpagesetup.c',
'gtkpaned.c',
'gtkpango.c',
'gskpango.c',
'gtkpapersize.c',
'gtkpathbar.c',
'gtkplacessidebar.c',