mutter/pango/cogl-pango-display-list.c
Robert Bragg cce8645aba path 2.0: update path API for experimental 2.0 API
When COGL_ENABLE_EXPERIMENTAL_2_0_API is defined cogl.h will now include
cogl2-path.h which changes cogl_path_new() so it can directly return a
CoglPath pointer; it no longer exposes a prototype for
cogl_{get,set}_path and all the remaining cogl_path_ functions now take
an explicit path as their first argument.

The idea is that we want to encourage developers to retain path objects
for as long as possible so they can take advantage of us uploading the
path geometry to the GPU. Currently although it is possible to start a
new path and query the current path, it is not convenient.

The other thing is that we want to get Cogl to the point where nothing
depends on a global, current context variable. This will allow us to one
day define a sensible threading model if/when that is ever desired.
2010-11-11 13:17:26 +00:00

435 lines
13 KiB
C

/*
* Clutter.
*
* An OpenGL based 'interactive canvas' library.
*
* Authored By Neil Roberts <neil@linux.intel.com>
*
* Copyright (C) 2009 Intel Corporation.
*
* 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
#include <glib.h>
#include <cogl/cogl.h>
#include <string.h>
#include "cogl-pango-display-list.h"
typedef enum
{
COGL_PANGO_DISPLAY_LIST_TEXTURE,
COGL_PANGO_DISPLAY_LIST_RECTANGLE,
COGL_PANGO_DISPLAY_LIST_TRAPEZOID
} CoglPangoDisplayListNodeType;
typedef struct _CoglPangoDisplayListNode CoglPangoDisplayListNode;
typedef struct _CoglPangoDisplayListVertex CoglPangoDisplayListVertex;
struct _CoglPangoDisplayList
{
gboolean color_override;
CoglColor color;
GSList *nodes;
GSList *last_node;
};
struct _CoglPangoDisplayListNode
{
CoglPangoDisplayListNodeType type;
gboolean color_override;
CoglColor color;
union
{
struct
{
/* The texture to render these coords from */
CoglHandle texture;
/* Array of vertex data to render out of this texture */
GArray *verts;
/* A VBO representing those vertices */
CoglHandle vertex_buffer;
} texture;
struct
{
float x_1, y_1;
float x_2, y_2;
} rectangle;
struct
{
float y_1;
float x_11;
float x_21;
float y_2;
float x_12;
float x_22;
} trapezoid;
} d;
};
struct _CoglPangoDisplayListVertex
{
float x, y, t_x, t_y;
};
CoglPangoDisplayList *
_cogl_pango_display_list_new (void)
{
return g_slice_new0 (CoglPangoDisplayList);
}
static void
_cogl_pango_display_list_append_node (CoglPangoDisplayList *dl,
CoglPangoDisplayListNode *node)
{
if (dl->last_node)
dl->last_node = dl->last_node->next = g_slist_prepend (NULL, node);
else
dl->last_node = dl->nodes = g_slist_prepend (NULL, node);
}
void
_cogl_pango_display_list_set_color_override (CoglPangoDisplayList *dl,
const CoglColor *color)
{
dl->color_override = TRUE;
dl->color = *color;
}
void
_cogl_pango_display_list_remove_color_override (CoglPangoDisplayList *dl)
{
dl->color_override = FALSE;
}
void
_cogl_pango_display_list_add_texture (CoglPangoDisplayList *dl,
CoglHandle texture,
float x_1, float y_1,
float x_2, float y_2,
float tx_1, float ty_1,
float tx_2, float ty_2)
{
CoglPangoDisplayListNode *node;
CoglPangoDisplayListVertex *verts;
/* Add to the last node if it is a texture node with the same
target texture */
if (dl->last_node
&& (node = dl->last_node->data)->type == COGL_PANGO_DISPLAY_LIST_TEXTURE
&& node->d.texture.texture == texture
&& (dl->color_override
? (node->color_override && cogl_color_equal (&dl->color, &node->color))
: !node->color_override))
{
/* Get rid of the vertex buffer so that it will be recreated */
if (node->d.texture.vertex_buffer != COGL_INVALID_HANDLE)
{
cogl_handle_unref (node->d.texture.vertex_buffer);
node->d.texture.vertex_buffer = COGL_INVALID_HANDLE;
}
}
else
{
/* Otherwise create a new node */
node = g_slice_new (CoglPangoDisplayListNode);
node->type = COGL_PANGO_DISPLAY_LIST_TEXTURE;
node->color_override = dl->color_override;
node->color = dl->color;
node->d.texture.texture = cogl_handle_ref (texture);
node->d.texture.verts
= g_array_new (FALSE, FALSE, sizeof (CoglPangoDisplayListVertex));
node->d.texture.vertex_buffer = COGL_INVALID_HANDLE;
_cogl_pango_display_list_append_node (dl, node);
}
g_array_set_size (node->d.texture.verts,
node->d.texture.verts->len + 4);
verts = &g_array_index (node->d.texture.verts,
CoglPangoDisplayListVertex,
node->d.texture.verts->len - 4);
verts->x = x_1;
verts->y = y_1;
verts->t_x = tx_1;
verts->t_y = ty_1;
verts++;
verts->x = x_1;
verts->y = y_2;
verts->t_x = tx_1;
verts->t_y = ty_2;
verts++;
verts->x = x_2;
verts->y = y_2;
verts->t_x = tx_2;
verts->t_y = ty_2;
verts++;
verts->x = x_2;
verts->y = y_1;
verts->t_x = tx_2;
verts->t_y = ty_1;
}
void
_cogl_pango_display_list_add_rectangle (CoglPangoDisplayList *dl,
float x_1, float y_1,
float x_2, float y_2)
{
CoglPangoDisplayListNode *node = g_slice_new (CoglPangoDisplayListNode);
node->type = COGL_PANGO_DISPLAY_LIST_RECTANGLE;
node->color_override = dl->color_override;
node->color = dl->color;
node->d.rectangle.x_1 = x_1;
node->d.rectangle.y_1 = y_1;
node->d.rectangle.x_2 = x_2;
node->d.rectangle.y_2 = y_2;
_cogl_pango_display_list_append_node (dl, node);
}
void
_cogl_pango_display_list_add_trapezoid (CoglPangoDisplayList *dl,
float y_1,
float x_11,
float x_21,
float y_2,
float x_12,
float x_22)
{
CoglPangoDisplayListNode *node = g_slice_new (CoglPangoDisplayListNode);
node->type = COGL_PANGO_DISPLAY_LIST_TRAPEZOID;
node->color_override = dl->color_override;
node->color = dl->color;
node->d.trapezoid.y_1 = y_1;
node->d.trapezoid.x_11 = x_11;
node->d.trapezoid.x_21 = x_21;
node->d.trapezoid.y_2 = y_2;
node->d.trapezoid.x_12 = x_12;
node->d.trapezoid.x_22 = x_22;
_cogl_pango_display_list_append_node (dl, node);
}
static void
emit_rectangles_through_journal (CoglPangoDisplayListNode *node)
{
int i;
for (i = 0; i < node->d.texture.verts->len; i += 4)
{
CoglPangoDisplayListVertex *v0 =
&g_array_index (node->d.texture.verts,
CoglPangoDisplayListVertex, i);
CoglPangoDisplayListVertex *v1 =
&g_array_index (node->d.texture.verts,
CoglPangoDisplayListVertex, i + 2);
cogl_rectangle_with_texture_coords (v0->x, v0->y, v1->x, v1->y,
v0->t_x, v0->t_y,
v1->t_x, v1->t_y);
}
}
static void
emit_vertex_buffer_geometry (CoglPangoDisplayListNode *node)
{
/* It's expensive to go through the Cogl journal for large runs
* of text in part because the journal transforms the quads in software
* to avoid changing the modelview matrix. So for larger runs of text
* we load the vertices into a VBO, and this has the added advantage
* that if the text doesn't change from frame to frame the VBO can
* be re-used avoiding the repeated cost of validating the data and
* mapping it into the GPU... */
if (node->d.texture.vertex_buffer == COGL_INVALID_HANDLE)
{
CoglHandle vb = cogl_vertex_buffer_new (node->d.texture.verts->len);
cogl_vertex_buffer_add (vb, "gl_Vertex", 2,
COGL_ATTRIBUTE_TYPE_FLOAT, FALSE,
sizeof (CoglPangoDisplayListVertex),
&g_array_index (node->d.texture.verts,
CoglPangoDisplayListVertex, 0).x);
cogl_vertex_buffer_add (vb, "gl_MultiTexCoord0", 2,
COGL_ATTRIBUTE_TYPE_FLOAT, FALSE,
sizeof (CoglPangoDisplayListVertex),
&g_array_index (node->d.texture.verts,
CoglPangoDisplayListVertex,
0).t_x);
cogl_vertex_buffer_submit (vb);
node->d.texture.vertex_buffer = vb;
}
#ifdef CLUTTER_COGL_HAS_GL
cogl_vertex_buffer_draw (node->d.texture.vertex_buffer,
GL_QUADS,
0, node->d.texture.verts->len);
#else /* CLUTTER_COGL_HAS_GL */
{
/* GLES doesn't support GL_QUADS so instead we use a VBO with
indexed vertices to generate GL_TRIANGLES from the quads */
int n_indices = node->d.texture.verts->len / 4 * 6;
CoglHandle indices_vbo
= cogl_vertex_buffer_indices_get_for_quads (n_indices);
cogl_vertex_buffer_draw_elements (node->d.texture.vertex_buffer,
COGL_VERTICES_MODE_TRIANGLES,
indices_vbo,
0, node->d.texture.verts->len - 1,
0, n_indices);
}
#endif /* CLUTTER_COGL_HAS_GL */
}
static void
_cogl_pango_display_list_render_texture (CoglMaterial *material,
const CoglColor *color,
CoglPangoDisplayListNode *node)
{
CoglColor premult_color = *color;
cogl_material_set_layer (material, 0, node->d.texture.texture);
cogl_material_set_color (material, &premult_color);
cogl_push_source (material);
/* For small runs of text like icon labels, we can get better performance
* going through the Cogl journal since text may then be batched together
* with other geometry. */
/* FIXME: 100 is a number I plucked out of thin air; it would be good
* to determine this empirically! */
if (node->d.texture.verts->len < 100)
emit_rectangles_through_journal (node);
else
emit_vertex_buffer_geometry (node);
cogl_pop_source ();
}
void
_cogl_pango_display_list_render (CoglPangoDisplayList *dl,
const CoglColor *color,
CoglMaterial *glyph_material,
CoglMaterial *solid_material)
{
GSList *l;
for (l = dl->nodes; l; l = l->next)
{
CoglPangoDisplayListNode *node = l->data;
CoglColor draw_color;
if (node->color_override)
/* Use the override color but preserve the alpha from the
draw color */
cogl_color_init_from_4ub (&draw_color,
cogl_color_get_red_byte (&node->color),
cogl_color_get_green_byte (&node->color),
cogl_color_get_blue_byte (&node->color),
cogl_color_get_alpha_byte (color));
else
draw_color = *color;
cogl_color_premultiply (&draw_color);
switch (node->type)
{
case COGL_PANGO_DISPLAY_LIST_TEXTURE:
_cogl_pango_display_list_render_texture (glyph_material,
&draw_color, node);
break;
case COGL_PANGO_DISPLAY_LIST_RECTANGLE:
cogl_material_set_color (solid_material, &draw_color);
cogl_push_source (solid_material);
cogl_rectangle (node->d.rectangle.x_1,
node->d.rectangle.y_1,
node->d.rectangle.x_2,
node->d.rectangle.y_2);
cogl_pop_source ();
break;
case COGL_PANGO_DISPLAY_LIST_TRAPEZOID:
{
float points[8];
CoglPath *path;
points[0] = node->d.trapezoid.x_11;
points[1] = node->d.trapezoid.y_1;
points[2] = node->d.trapezoid.x_12;
points[3] = node->d.trapezoid.y_2;
points[4] = node->d.trapezoid.x_22;
points[5] = node->d.trapezoid.y_2;
points[6] = node->d.trapezoid.x_21;
points[7] = node->d.trapezoid.y_1;
cogl_material_set_color (solid_material, &draw_color);
cogl_push_source (solid_material);
path = cogl_path_new ();
cogl_path_polygon (path, points, 4);
cogl_path_fill (path);
cogl_object_unref (path);
cogl_pop_source ();
}
break;
}
}
}
static void
_cogl_pango_display_list_node_free (CoglPangoDisplayListNode *node)
{
if (node->type == COGL_PANGO_DISPLAY_LIST_TEXTURE)
{
g_array_free (node->d.texture.verts, TRUE);
if (node->d.texture.texture != COGL_INVALID_HANDLE)
cogl_handle_unref (node->d.texture.texture);
if (node->d.texture.vertex_buffer != COGL_INVALID_HANDLE)
cogl_handle_unref (node->d.texture.vertex_buffer);
}
g_slice_free (CoglPangoDisplayListNode, node);
}
void
_cogl_pango_display_list_clear (CoglPangoDisplayList *dl)
{
g_slist_foreach (dl->nodes, (GFunc) _cogl_pango_display_list_node_free, NULL);
g_slist_free (dl->nodes);
dl->nodes = NULL;
dl->last_node = NULL;
}
void
_cogl_pango_display_list_free (CoglPangoDisplayList *dl)
{
_cogl_pango_display_list_clear (dl);
g_slice_free (CoglPangoDisplayList, dl);
}