mutter/pango/cogl-pango-render.c
Neil Roberts 8123330061 cogl-pango: Use a CoglAtlas to maintain the glyph cache
The glyph cache is now stored in a CoglAtlas structure instead of the
custom atlasing code. This has the advantage that it can share code
with the main texture atlas and that it supports reorganizing the
atlas when it becomes full. Unlike the texture atlas, the glyph cache
can use multiple atlases which would be neccessary if the maximum
texture size is reached and we need to create a second
texture. Whenever a display list is created it now has to register a
callback with the glyph cache so that the display list can be
recreated whenever any of the atlases are reorganized. This is needed
because the display list directly stores texture coordinates within
the atlas texture and they would become invalid when the texture is
moved.

The ensure_glyphs_for_layout now works in two steps. First it reserves
space in the atlas for all of the glyphs. The atlas is created with
the DISABLE_MIGRATION flag so that it won't actually copy any textures
if any rearranging is needed. Whenever the position is updated for a
glyph then it is marked as dirty. After space for all of the glyphs
has been reserved it will iterate over all dirty glyphs and redraw
them using Cairo. The rendered glyph is then stored in the texture
with a sub texture update.

The glyphs need to all be set at the right location before starting to
create the display list because the display list stores the texture
coordinates of the glyph. If any of the glyphs were moved around then
the parts of the display list that was created already would become
invalid. To make this work, ensure_glyphs_for_layout is now always
called before rendering a layout or a layout line.
2010-08-12 11:56:59 +01:00

770 lines
24 KiB
C

/*
* Clutter.
*
* An OpenGL based 'interactive canvas' library.
*
* Authored By Matthew Allum <mallum@openedhand.com>
*
* Copyright (C) 2008 OpenedHand
*
* 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/>.
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#ifndef PANGO_ENABLE_BACKEND
#define PANGO_ENABLE_BACKEND 1
#endif
#include <pango/pango-fontmap.h>
#include <pango/pangocairo.h>
#include <pango/pango-renderer.h>
#include <cairo.h>
#include "cogl/cogl-debug.h"
#include "cogl-pango-private.h"
#include "cogl-pango-glyph-cache.h"
#include "cogl-pango-display-list.h"
struct _CoglPangoRenderer
{
PangoRenderer parent_instance;
/* The material used to texture from the glyph cache with */
CoglHandle glyph_material;
/* The material used for solid fills. (boxes, rectangles + trapezoids) */
CoglHandle solid_material;
/* Caches of glyphs as textures */
CoglPangoGlyphCache *glyph_cache;
/* The current display list that is being built */
CoglPangoDisplayList *display_list;
};
struct _CoglPangoRendererClass
{
PangoRendererClass class_instance;
};
typedef struct _CoglPangoRendererQdata CoglPangoRendererQdata;
/* An instance of this struct gets attached to each PangoLayout to
cache the VBO and to detect changes to the layout */
struct _CoglPangoRendererQdata
{
CoglPangoRenderer *renderer;
/* The cache of the geometry for the layout */
CoglPangoDisplayList *display_list;
/* A reference to the first line of the layout. This is just used to
detect changes */
PangoLayoutLine *first_line;
};
static void
_cogl_pango_ensure_glyph_cache_for_layout_line (PangoLayoutLine *line);
static void
cogl_pango_renderer_draw_glyph (CoglPangoRenderer *priv,
CoglPangoGlyphCacheValue *cache_value,
float x1,
float y1)
{
float x2, y2;
g_return_if_fail (priv->display_list != NULL);
x2 = x1 + (float) cache_value->draw_width;
y2 = y1 + (float) cache_value->draw_height;
_cogl_pango_display_list_add_texture (priv->display_list,
cache_value->texture,
x1, y1, x2, y2,
cache_value->tx1,
cache_value->ty1,
cache_value->tx2,
cache_value->ty2);
}
static void cogl_pango_renderer_finalize (GObject *object);
static void cogl_pango_renderer_draw_glyphs (PangoRenderer *renderer,
PangoFont *font,
PangoGlyphString *glyphs,
int x,
int y);
static void cogl_pango_renderer_draw_rectangle (PangoRenderer *renderer,
PangoRenderPart part,
int x,
int y,
int width,
int height);
static void cogl_pango_renderer_draw_trapezoid (PangoRenderer *renderer,
PangoRenderPart part,
double y1,
double x11,
double x21,
double y2,
double x12,
double x22);
G_DEFINE_TYPE (CoglPangoRenderer, cogl_pango_renderer, PANGO_TYPE_RENDERER);
static void
cogl_pango_renderer_init (CoglPangoRenderer *priv)
{
priv->glyph_material = cogl_material_new ();
/* The default combine mode of materials is to modulate (A x B) the texture
* RGBA channels with the RGBA channels of the previous layer (which in our
* case is just the font color)
*
* Since the RGB for an alpha texture is defined as 0, this gives us:
*
* result.rgb = color.rgb * 0
* result.a = color.a * texture.a
*
* What we want is premultiplied rgba values:
*
* result.rgba = color.rgb * texture.a
* result.a = color.a * texture.a
*/
cogl_material_set_layer_combine (priv->glyph_material, 0, /* layer */
"RGBA = MODULATE (PREVIOUS, TEXTURE[A])",
NULL);
cogl_material_set_layer_wrap_mode (priv->glyph_material, 0,
COGL_MATERIAL_WRAP_MODE_CLAMP_TO_EDGE);
priv->solid_material = cogl_material_new ();
priv->glyph_cache = cogl_pango_glyph_cache_new ();
_cogl_pango_renderer_set_use_mipmapping (priv, FALSE);
}
static void
cogl_pango_renderer_class_init (CoglPangoRendererClass *klass)
{
GObjectClass *object_class = G_OBJECT_CLASS (klass);
PangoRendererClass *renderer_class = PANGO_RENDERER_CLASS (klass);
object_class->finalize = cogl_pango_renderer_finalize;
renderer_class->draw_glyphs = cogl_pango_renderer_draw_glyphs;
renderer_class->draw_rectangle = cogl_pango_renderer_draw_rectangle;
renderer_class->draw_trapezoid = cogl_pango_renderer_draw_trapezoid;
}
static void
cogl_pango_renderer_finalize (GObject *object)
{
CoglPangoRenderer *priv = COGL_PANGO_RENDERER (object);
cogl_pango_glyph_cache_free (priv->glyph_cache);
G_OBJECT_CLASS (cogl_pango_renderer_parent_class)->finalize (object);
}
static CoglPangoRenderer *
cogl_pango_get_renderer_from_context (PangoContext *context)
{
PangoFontMap *font_map;
PangoRenderer *renderer;
CoglPangoFontMap *font_map_priv;
font_map = pango_context_get_font_map (context);
g_return_val_if_fail (COGL_PANGO_IS_FONT_MAP (font_map), NULL);
font_map_priv = COGL_PANGO_FONT_MAP (font_map);
renderer = cogl_pango_font_map_get_renderer (font_map_priv);
g_return_val_if_fail (COGL_PANGO_IS_RENDERER (renderer), NULL);
return COGL_PANGO_RENDERER (renderer);
}
static GQuark
cogl_pango_render_get_qdata_key (void)
{
static GQuark key = 0;
if (G_UNLIKELY (key == 0))
key = g_quark_from_static_string ("CoglPangoDisplayList");
return key;
}
static void
cogl_pango_render_qdata_forget_display_list (CoglPangoRendererQdata *qdata)
{
if (qdata->display_list)
{
_cogl_pango_glyph_cache_remove_reorganize_callback
(qdata->renderer->glyph_cache,
(CoglCallbackListFunc) cogl_pango_render_qdata_forget_display_list,
qdata);
_cogl_pango_display_list_free (qdata->display_list);
qdata->display_list = NULL;
}
}
static void
cogl_pango_render_qdata_destroy (CoglPangoRendererQdata *qdata)
{
cogl_pango_render_qdata_forget_display_list (qdata);
if (qdata->first_line)
pango_layout_line_unref (qdata->first_line);
g_slice_free (CoglPangoRendererQdata, qdata);
}
/**
* cogl_pango_render_layout_subpixel:
* @layout: a #PangoLayout
* @x: FIXME
* @y: FIXME
* @color: color to use when rendering the layout
* @flags: flags to pass to the renderer
*
* FIXME
*
* Since: 1.0
*/
void
cogl_pango_render_layout_subpixel (PangoLayout *layout,
int x,
int y,
const CoglColor *color,
int flags)
{
PangoContext *context;
CoglPangoRenderer *priv;
CoglPangoRendererQdata *qdata;
context = pango_layout_get_context (layout);
priv = cogl_pango_get_renderer_from_context (context);
if (G_UNLIKELY (!priv))
return;
qdata = g_object_get_qdata (G_OBJECT (layout),
cogl_pango_render_get_qdata_key ());
if (qdata == NULL)
{
qdata = g_slice_new0 (CoglPangoRendererQdata);
qdata->renderer = priv;
g_object_set_qdata_full (G_OBJECT (layout),
cogl_pango_render_get_qdata_key (),
qdata,
(GDestroyNotify)
cogl_pango_render_qdata_destroy);
}
/* Check if the layout has changed since the last build of the
display list. This trick was suggested by Behdad Esfahbod here:
http://mail.gnome.org/archives/gtk-i18n-list/2009-May/msg00019.html */
if (qdata->display_list && qdata->first_line
&& qdata->first_line->layout != layout)
cogl_pango_render_qdata_forget_display_list (qdata);
if (qdata->display_list == NULL)
{
cogl_pango_ensure_glyph_cache_for_layout (layout);
qdata->display_list = _cogl_pango_display_list_new ();
/* Register for notification of when the glyph cache changes so
we can rebuild the display list */
_cogl_pango_glyph_cache_add_reorganize_callback
(priv->glyph_cache,
(CoglCallbackListFunc) cogl_pango_render_qdata_forget_display_list,
qdata);
priv->display_list = qdata->display_list;
pango_renderer_draw_layout (PANGO_RENDERER (priv), layout, 0, 0);
priv->display_list = NULL;
}
cogl_push_matrix ();
cogl_translate (x / (gfloat) PANGO_SCALE, y / (gfloat) PANGO_SCALE, 0);
_cogl_pango_display_list_render (qdata->display_list,
color,
priv->glyph_material,
priv->solid_material);
cogl_pop_matrix ();
/* Keep a reference to the first line of the layout so we can detect
changes */
if (qdata->first_line)
{
pango_layout_line_unref (qdata->first_line);
qdata->first_line = NULL;
}
if (pango_layout_get_line_count (layout) > 0)
{
qdata->first_line = pango_layout_get_line (layout, 0);
pango_layout_line_ref (qdata->first_line);
}
}
/**
* cogl_pango_render_layout:
* @layout: a #PangoLayout
* @x: X coordinate to render the layout at
* @y: Y coordinate to render the layout at
* @color: color to use when rendering the layout
* @flags: flags to pass to the renderer
*
* Renders @layout.
*
* Since: 1.0
*/
void
cogl_pango_render_layout (PangoLayout *layout,
int x,
int y,
const CoglColor *color,
int flags)
{
cogl_pango_render_layout_subpixel (layout,
x * PANGO_SCALE,
y * PANGO_SCALE,
color,
flags);
}
/**
* cogl_pango_render_layout_line:
* @line: a #PangoLayoutLine
* @x: X coordinate to render the line at
* @y: Y coordinate to render the line at
* @color: color to use when rendering the line
*
* Renders @line at the given coordinates using the given color.
*
* Since: 1.0
*/
void
cogl_pango_render_layout_line (PangoLayoutLine *line,
int x,
int y,
const CoglColor *color)
{
PangoContext *context;
CoglPangoRenderer *priv;
context = pango_layout_get_context (line->layout);
priv = cogl_pango_get_renderer_from_context (context);
if (G_UNLIKELY (!priv))
return;
priv->display_list = _cogl_pango_display_list_new ();
_cogl_pango_ensure_glyph_cache_for_layout_line (line);
pango_renderer_draw_layout_line (PANGO_RENDERER (priv), line, x, y);
_cogl_pango_display_list_render (priv->display_list,
color,
priv->glyph_material,
priv->solid_material);
_cogl_pango_display_list_free (priv->display_list);
priv->display_list = NULL;
}
void
_cogl_pango_renderer_clear_glyph_cache (CoglPangoRenderer *renderer)
{
cogl_pango_glyph_cache_clear (renderer->glyph_cache);
}
void
_cogl_pango_renderer_set_use_mipmapping (CoglPangoRenderer *renderer,
gboolean value)
{
if (value)
cogl_material_set_layer_filters (renderer->glyph_material, 0,
COGL_MATERIAL_FILTER_LINEAR_MIPMAP_LINEAR,
COGL_MATERIAL_FILTER_LINEAR);
else
cogl_material_set_layer_filters (renderer->glyph_material, 0,
COGL_MATERIAL_FILTER_LINEAR,
COGL_MATERIAL_FILTER_LINEAR);
}
gboolean
_cogl_pango_renderer_get_use_mipmapping (CoglPangoRenderer *renderer)
{
const GList *layers = cogl_material_get_layers (renderer->glyph_material);
g_return_val_if_fail (layers != NULL, FALSE);
return (cogl_material_layer_get_min_filter (layers->data)
== COGL_MATERIAL_FILTER_LINEAR_MIPMAP_LINEAR);
}
static CoglPangoGlyphCacheValue *
cogl_pango_renderer_get_cached_glyph (PangoRenderer *renderer,
gboolean create,
PangoFont *font,
PangoGlyph glyph)
{
CoglPangoRenderer *priv = COGL_PANGO_RENDERER (renderer);
return cogl_pango_glyph_cache_lookup (priv->glyph_cache, create, font, glyph);
}
static void
cogl_pango_renderer_set_dirty_glyph (PangoFont *font,
PangoGlyph glyph,
CoglPangoGlyphCacheValue *value)
{
cairo_surface_t *surface;
cairo_t *cr;
cairo_scaled_font_t *scaled_font;
cairo_glyph_t cairo_glyph;
COGL_NOTE (PANGO, "redrawing glyph %i", glyph);
surface = cairo_image_surface_create (CAIRO_FORMAT_A8,
value->draw_width,
value->draw_height);
cr = cairo_create (surface);
scaled_font = pango_cairo_font_get_scaled_font (PANGO_CAIRO_FONT (font));
cairo_set_scaled_font (cr, scaled_font);
cairo_glyph.x = -value->draw_x;
cairo_glyph.y = -value->draw_y;
/* The PangoCairo glyph numbers directly map to Cairo glyph
numbers */
cairo_glyph.index = glyph;
cairo_show_glyphs (cr, &cairo_glyph, 1);
cairo_destroy (cr);
cairo_surface_flush (surface);
/* Copy the glyph to the texture */
cogl_texture_set_region (value->texture,
0, /* src_x */
0, /* src_y */
value->tx_pixel, /* dst_x */
value->ty_pixel, /* dst_y */
value->draw_width, /* dst_width */
value->draw_height, /* dst_height */
value->draw_width, /* width */
value->draw_height, /* height */
COGL_PIXEL_FORMAT_A_8,
cairo_image_surface_get_stride (surface),
cairo_image_surface_get_data (surface));
cairo_surface_destroy (surface);
}
static void
_cogl_pango_ensure_glyph_cache_for_layout_line_internal (PangoLayoutLine *line)
{
PangoContext *context;
PangoRenderer *renderer;
GSList *l;
context = pango_layout_get_context (line->layout);
renderer =
PANGO_RENDERER (cogl_pango_get_renderer_from_context (context));
for (l = line->runs; l; l = l->next)
{
PangoLayoutRun *run = l->data;
PangoGlyphString *glyphs = run->glyphs;
int i;
for (i = 0; i < glyphs->num_glyphs; i++)
{
PangoGlyphInfo *gi = &glyphs->glyphs[i];
/* If the glyph isn't cached then this will reserve
space for it now. We won't actually draw the glyph
yet because reserving space could cause all of the
other glyphs to be moved so we might as well redraw
them all later once we know that the position is
settled */
cogl_pango_renderer_get_cached_glyph (renderer, TRUE,
run->item->analysis.font,
gi->glyph);
}
}
}
static void
_cogl_pango_ensure_glyph_cache_for_layout_line (PangoLayoutLine *line)
{
PangoContext *context;
CoglPangoRenderer *priv;
context = pango_layout_get_context (line->layout);
priv = cogl_pango_get_renderer_from_context (context);
_cogl_pango_ensure_glyph_cache_for_layout_line_internal (line);
/* Now that we know all of the positions are settled we'll fill in
any dirty glyphs */
_cogl_pango_glyph_cache_set_dirty_glyphs
(priv->glyph_cache, cogl_pango_renderer_set_dirty_glyph);
}
void
cogl_pango_ensure_glyph_cache_for_layout (PangoLayout *layout)
{
PangoContext *context;
CoglPangoRenderer *priv;
PangoLayoutIter *iter;
context = pango_layout_get_context (layout);
priv = cogl_pango_get_renderer_from_context (context);
g_return_if_fail (PANGO_IS_LAYOUT (layout));
if ((iter = pango_layout_get_iter (layout)) == NULL)
return;
do
{
PangoLayoutLine *line;
line = pango_layout_iter_get_line_readonly (iter);
_cogl_pango_ensure_glyph_cache_for_layout_line_internal (line);
}
while (pango_layout_iter_next_line (iter));
pango_layout_iter_free (iter);
/* Now that we know all of the positions are settled we'll fill in
any dirty glyphs */
_cogl_pango_glyph_cache_set_dirty_glyphs
(priv->glyph_cache, cogl_pango_renderer_set_dirty_glyph);
}
static void
cogl_pango_renderer_set_color_for_part (PangoRenderer *renderer,
PangoRenderPart part)
{
PangoColor *pango_color = pango_renderer_get_color (renderer, part);
CoglPangoRenderer *priv = COGL_PANGO_RENDERER (renderer);
if (pango_color)
{
CoglColor color;
cogl_color_set_from_4ub (&color,
pango_color->red >> 8,
pango_color->green >> 8,
pango_color->blue >> 8,
0xff);
_cogl_pango_display_list_set_color_override (priv->display_list, &color);
}
else
_cogl_pango_display_list_remove_color_override (priv->display_list);
}
static void
cogl_pango_renderer_draw_box (PangoRenderer *renderer,
int x,
int y,
int width,
int height)
{
CoglPangoRenderer *priv = COGL_PANGO_RENDERER (renderer);
g_return_if_fail (priv->display_list != NULL);
_cogl_pango_display_list_add_rectangle (priv->display_list,
x,
y - height,
x + width,
y);
}
static void
cogl_pango_renderer_get_device_units (PangoRenderer *renderer,
int xin,
int yin,
float *xout,
float *yout)
{
const PangoMatrix *matrix;
if ((matrix = pango_renderer_get_matrix (renderer)))
{
/* Convert user-space coords to device coords */
*xout = ((xin * matrix->xx + yin * matrix->xy)
/ PANGO_SCALE + matrix->x0);
*yout = ((yin * matrix->yy + xin * matrix->yx)
/ PANGO_SCALE + matrix->y0);
}
else
{
*xout = PANGO_PIXELS (xin);
*yout = PANGO_PIXELS (yin);
}
}
static void
cogl_pango_renderer_draw_rectangle (PangoRenderer *renderer,
PangoRenderPart part,
int x,
int y,
int width,
int height)
{
CoglPangoRenderer *priv = COGL_PANGO_RENDERER (renderer);
float x1, x2, y1, y2;
g_return_if_fail (priv->display_list != NULL);
cogl_pango_renderer_set_color_for_part (renderer, part);
cogl_pango_renderer_get_device_units (renderer,
x, y,
&x1, &y1);
cogl_pango_renderer_get_device_units (renderer,
x + width, y + height,
&x2, &y2);
_cogl_pango_display_list_add_rectangle (priv->display_list,
x1, y1, x2, y2);
}
static void
cogl_pango_renderer_draw_trapezoid (PangoRenderer *renderer,
PangoRenderPart part,
double y1,
double x11,
double x21,
double y2,
double x12,
double x22)
{
CoglPangoRenderer *priv = COGL_PANGO_RENDERER (renderer);
float points[8];
g_return_if_fail (priv->display_list != NULL);
points[0] = (x11);
points[1] = (y1);
points[2] = (x12);
points[3] = (y2);
points[4] = (x22);
points[5] = points[3];
points[6] = (x21);
points[7] = points[1];
cogl_pango_renderer_set_color_for_part (renderer, part);
_cogl_pango_display_list_add_trapezoid (priv->display_list,
y1,
x11,
x21,
y2,
x12,
x22);
}
static void
cogl_pango_renderer_draw_glyphs (PangoRenderer *renderer,
PangoFont *font,
PangoGlyphString *glyphs,
int xi,
int yi)
{
CoglPangoRenderer *priv = (CoglPangoRenderer *) renderer;
CoglPangoGlyphCacheValue *cache_value;
int i;
cogl_pango_renderer_set_color_for_part (renderer,
PANGO_RENDER_PART_FOREGROUND);
for (i = 0; i < glyphs->num_glyphs; i++)
{
PangoGlyphInfo *gi = glyphs->glyphs + i;
float x, y;
cogl_pango_renderer_get_device_units (renderer,
xi + gi->geometry.x_offset,
yi + gi->geometry.y_offset,
&x, &y);
if ((gi->glyph & PANGO_GLYPH_UNKNOWN_FLAG))
{
PangoFontMetrics *metrics;
if (font == NULL ||
(metrics = pango_font_get_metrics (font, NULL)) == NULL)
{
cogl_pango_renderer_draw_box (renderer,
x,
y,
PANGO_UNKNOWN_GLYPH_WIDTH,
PANGO_UNKNOWN_GLYPH_HEIGHT);
}
else
{
cogl_pango_renderer_draw_box (renderer,
x,
y,
metrics->approximate_char_width
/ PANGO_SCALE,
metrics->ascent / PANGO_SCALE);
pango_font_metrics_unref (metrics);
}
}
else
{
/* Get the texture containing the glyph */
cache_value =
cogl_pango_renderer_get_cached_glyph (renderer,
FALSE,
font,
gi->glyph);
/* cogl_pango_ensure_glyph_cache_for_layout should always be
called before rendering a layout so we should never have
a dirty glyph here */
g_assert (cache_value == NULL || !cache_value->dirty);
if (cache_value == NULL)
{
cogl_pango_renderer_draw_box (renderer,
x,
y,
PANGO_UNKNOWN_GLYPH_WIDTH,
PANGO_UNKNOWN_GLYPH_HEIGHT);
}
else
{
x += (float)(cache_value->draw_x);
y += (float)(cache_value->draw_y);
cogl_pango_renderer_draw_glyph (priv, cache_value, x, y);
}
}
xi += gi->geometry.width;
}
}