mutter/cogl-pango/cogl-pango-display-list.c
Robert Bragg 92c3063014 framebuffer: Add cogl_framebuffer draw methods
This adds cogl_framebuffer_ apis for drawing attributes and primitives
that replace corresponding apis that depend on the default CoglContext.
This is part of the on going effort to adapt the Cogl api so it no
longer depends on a global context variable.

All the new drawing functions also take an explicit pipeline argument
since we are also aiming to avoid being a stateful api like Cairo and
OpenGL. Being stateless makes it easier for orthogonal components to
share access to the GPU. Being stateless should also minimize any
impedance miss-match for those wanting to build higher level stateless
apis on top of Cogl.

Note: none of the legacy, global state options such as
cogl_set_depth_test_enabled(), cogl_set_backface_culling_enabled() or
cogl_program_use() are supported by these new drawing apis and if set
will simply be silently ignored.

Reviewed-by: Neil Roberts <neil@linux.intel.com>
2012-02-09 13:09:15 +00:00

496 lines
15 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"
#include "cogl/cogl-context-private.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 _CoglPangoDisplayListRectangle CoglPangoDisplayListRectangle;
struct _CoglPangoDisplayList
{
gboolean color_override;
CoglColor color;
GSList *nodes;
GSList *last_node;
CoglPangoPipelineCache *pipeline_cache;
};
/* This matches the format expected by cogl_rectangles_with_texture_coords */
struct _CoglPangoDisplayListRectangle
{
float x_1, y_1, x_2, y_2;
float s_1, t_1, s_2, t_2;
};
struct _CoglPangoDisplayListNode
{
CoglPangoDisplayListNodeType type;
gboolean color_override;
CoglColor color;
CoglPipeline *pipeline;
union
{
struct
{
/* The texture to render these coords from */
CoglTexture *texture;
/* Array of rectangles in the format expected by
cogl_rectangles_with_texture_coords */
GArray *rectangles;
/* A primitive representing those vertices */
CoglPrimitive *primitive;
} 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;
};
CoglPangoDisplayList *
_cogl_pango_display_list_new (CoglPangoPipelineCache *pipeline_cache)
{
CoglPangoDisplayList *dl = g_slice_new0 (CoglPangoDisplayList);
dl->pipeline_cache = pipeline_cache;
return dl;
}
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,
CoglTexture *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;
CoglPangoDisplayListRectangle *rectangle;
/* 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.primitive != NULL)
{
cogl_object_unref (node->d.texture.primitive);
node->d.texture.primitive = NULL;
}
}
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->pipeline = NULL;
node->d.texture.texture = cogl_object_ref (texture);
node->d.texture.rectangles
= g_array_new (FALSE, FALSE, sizeof (CoglPangoDisplayListRectangle));
node->d.texture.primitive = NULL;
_cogl_pango_display_list_append_node (dl, node);
}
g_array_set_size (node->d.texture.rectangles,
node->d.texture.rectangles->len + 1);
rectangle = &g_array_index (node->d.texture.rectangles,
CoglPangoDisplayListRectangle,
node->d.texture.rectangles->len - 1);
rectangle->x_1 = x_1;
rectangle->y_1 = y_1;
rectangle->x_2 = x_2;
rectangle->y_2 = y_2;
rectangle->s_1 = tx_1;
rectangle->t_1 = ty_1;
rectangle->s_2 = tx_2;
rectangle->t_2 = ty_2;
}
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;
node->pipeline = NULL;
_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;
node->pipeline = NULL;
_cogl_pango_display_list_append_node (dl, node);
}
static void
emit_rectangles_through_journal (CoglPangoDisplayListNode *node)
{
cogl_rectangles_with_texture_coords ((float *)
node->d.texture.rectangles->data,
node->d.texture.rectangles->len);
}
static void
emit_vertex_buffer_geometry (CoglPangoDisplayListNode *node)
{
_COGL_GET_CONTEXT (ctx, NO_RETVAL);
/* 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.primitive == NULL)
{
CoglAttributeBuffer *buffer;
CoglVertexP2T2 *verts, *v;
int n_verts;
gboolean allocated = FALSE;
CoglAttribute *attributes[2];
CoglPrimitive *prim;
int i;
n_verts = node->d.texture.rectangles->len * 4;
buffer
= cogl_attribute_buffer_new (n_verts * sizeof (CoglVertexP2T2), NULL);
if ((verts = cogl_buffer_map (COGL_BUFFER (buffer),
COGL_BUFFER_ACCESS_WRITE,
COGL_BUFFER_MAP_HINT_DISCARD)) == NULL)
{
verts = g_new (CoglVertexP2T2, n_verts);
allocated = TRUE;
}
v = verts;
/* Copy the rectangles into the buffer and expand into four
vertices instead of just two */
for (i = 0; i < node->d.texture.rectangles->len; i++)
{
const CoglPangoDisplayListRectangle *rectangle
= &g_array_index (node->d.texture.rectangles,
CoglPangoDisplayListRectangle, i);
v->x = rectangle->x_1;
v->y = rectangle->y_1;
v->s = rectangle->s_1;
v->t = rectangle->t_1;
v++;
v->x = rectangle->x_1;
v->y = rectangle->y_2;
v->s = rectangle->s_1;
v->t = rectangle->t_2;
v++;
v->x = rectangle->x_2;
v->y = rectangle->y_2;
v->s = rectangle->s_2;
v->t = rectangle->t_2;
v++;
v->x = rectangle->x_2;
v->y = rectangle->y_1;
v->s = rectangle->s_2;
v->t = rectangle->t_1;
v++;
}
if (allocated)
{
cogl_buffer_set_data (COGL_BUFFER (buffer),
0, /* offset */
verts,
sizeof (CoglVertexP2T2) * n_verts);
g_free (verts);
}
else
cogl_buffer_unmap (COGL_BUFFER (buffer));
attributes[0] = cogl_attribute_new (buffer,
"cogl_position_in",
sizeof (CoglVertexP2T2),
G_STRUCT_OFFSET (CoglVertexP2T2, x),
2, /* n_components */
COGL_ATTRIBUTE_TYPE_FLOAT);
attributes[1] = cogl_attribute_new (buffer,
"cogl_tex_coord0_in",
sizeof (CoglVertexP2T2),
G_STRUCT_OFFSET (CoglVertexP2T2, s),
2, /* n_components */
COGL_ATTRIBUTE_TYPE_FLOAT);
prim = cogl_primitive_new_with_attributes (COGL_VERTICES_MODE_TRIANGLES,
n_verts,
attributes,
2 /* n_attributes */);
#ifdef CLUTTER_COGL_HAS_GL
if (ctx->driver == COGL_DRIVER_GL)
cogl_primitive_set_mode (prim, GL_QUADS);
else
#endif
{
/* GLES doesn't support GL_QUADS so instead we use a VBO
with indexed vertices to generate GL_TRIANGLES from the
quads */
CoglIndices *indices =
cogl_get_rectangle_indices (node->d.texture.rectangles->len);
cogl_primitive_set_indices (prim, indices,
node->d.texture.rectangles->len * 6);
}
node->d.texture.primitive = prim;
cogl_object_unref (buffer);
cogl_object_unref (attributes[0]);
cogl_object_unref (attributes[1]);
}
cogl_framebuffer_draw_primitive (cogl_get_draw_framebuffer (),
cogl_get_source (),
node->d.texture.primitive);
}
static void
_cogl_pango_display_list_render_texture (CoglPangoDisplayListNode *node)
{
/* 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: 25 is a number I plucked out of thin air; it would be good
* to determine this empirically! */
if (node->d.texture.rectangles->len < 25)
emit_rectangles_through_journal (node);
else
emit_vertex_buffer_geometry (node);
}
void
_cogl_pango_display_list_render (CoglPangoDisplayList *dl,
const CoglColor *color)
{
GSList *l;
for (l = dl->nodes; l; l = l->next)
{
CoglPangoDisplayListNode *node = l->data;
CoglColor draw_color;
if (node->pipeline == NULL)
{
if (node->type == COGL_PANGO_DISPLAY_LIST_TEXTURE)
node->pipeline =
_cogl_pango_pipeline_cache_get (dl->pipeline_cache,
node->d.texture.texture);
else
node->pipeline =
_cogl_pango_pipeline_cache_get (dl->pipeline_cache,
NULL);
}
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);
cogl_pipeline_set_color (node->pipeline, &draw_color);
cogl_push_source (node->pipeline);
switch (node->type)
{
case COGL_PANGO_DISPLAY_LIST_TEXTURE:
_cogl_pango_display_list_render_texture (node);
break;
case COGL_PANGO_DISPLAY_LIST_RECTANGLE:
cogl_rectangle (node->d.rectangle.x_1,
node->d.rectangle.y_1,
node->d.rectangle.x_2,
node->d.rectangle.y_2);
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;
path = cogl_path_new ();
cogl_path_polygon (path, points, 4);
cogl_path_fill (path);
cogl_object_unref (path);
}
break;
}
cogl_pop_source ();
}
}
static void
_cogl_pango_display_list_node_free (CoglPangoDisplayListNode *node)
{
if (node->type == COGL_PANGO_DISPLAY_LIST_TEXTURE)
{
g_array_free (node->d.texture.rectangles, TRUE);
if (node->d.texture.texture != NULL)
cogl_object_unref (node->d.texture.texture);
if (node->d.texture.primitive != NULL)
cogl_object_unref (node->d.texture.primitive);
}
if (node->pipeline)
cogl_object_unref (node->pipeline);
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);
}