[gtk+] Add a Pango renderer
- From: Matthias Clasen <matthiasc src gnome org>
- To: commits-list gnome org
- Cc:
- Subject: [gtk+] Add a Pango renderer
- Date: Fri, 1 Sep 2017 17:30:31 +0000 (UTC)
commit 82e8f3a54235df54981c1f6d26c3c497c6565f30
Author: Matthias Clasen <mclasen redhat com>
Date: Wed Aug 30 11:12:50 2017 -0400
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.
gtk/gskpango.c | 531 +++++++++++++++++++++++++++++++++++++++++++++++++++++++
gtk/gskpango.h | 45 +++++
gtk/meson.build | 1 +
3 files changed, 577 insertions(+), 0 deletions(-)
---
diff --git a/gtk/gskpango.c b/gtk/gskpango.c
new file mode 100644
index 0000000..c602008
--- /dev/null
+++ b/gtk/gskpango.c
@@ -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);
+}
diff --git a/gtk/gskpango.h b/gtk/gskpango.h
new file mode 100644
index 0000000..f8703d2
--- /dev/null
+++ b/gtk/gskpango.h
@@ -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__ */
diff --git a/gtk/meson.build b/gtk/meson.build
index a5985a3..5fed5b7 100644
--- a/gtk/meson.build
+++ b/gtk/meson.build
@@ -231,6 +231,7 @@ gtk_public_sources = files([
'gtkpagesetup.c',
'gtkpaned.c',
'gtkpango.c',
+ 'gskpango.c',
'gtkpapersize.c',
'gtkpathbar.c',
'gtkplacessidebar.c',
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