mutter/clutter/cogl/gl/cogl-primitives.c
Robert Bragg a2cf7e4a19 [Automatic fixed-to-float.sh change] Applies a number fixed to float patches
To deal with all the corner cases that couldn't be scripted a number of patches
were written for the remaining 10% of the effort.

Note: again no API changes were made in Clutter, only in Cogl.
2009-01-20 16:20:54 +00:00

245 lines
6.8 KiB
C

/*
* Clutter COGL
*
* A basic GL/GLES Abstraction/Utility Layer
*
* Authored By Matthew Allum <mallum@openedhand.com>
*
* Copyright (C) 2007 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, write to the
* Free Software Foundation, Inc., 59 Temple Place - Suite 330,
* Boston, MA 02111-1307, USA.
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include "cogl.h"
#include "cogl-internal.h"
#include "cogl-context.h"
#include "cogl-clip-stack.h"
#include <string.h>
#include <gmodule.h>
#include <math.h>
#define _COGL_MAX_BEZ_RECURSE_DEPTH 16
void
_cogl_rectangle (float x,
float y,
float width,
float height)
{
_COGL_GET_CONTEXT (ctx, NO_RETVAL);
cogl_enable (ctx->color_alpha < 255
? COGL_ENABLE_BLEND : 0);
GE( glRectf (x, y, x + width, y + height) );
}
void
_cogl_path_add_node (gboolean new_sub_path,
float x,
float y)
{
CoglPathNode new_node;
_COGL_GET_CONTEXT (ctx, NO_RETVAL);
new_node.x = (x);
new_node.y = (y);
new_node.path_size = 0;
if (new_sub_path || ctx->path_nodes->len == 0)
ctx->last_path = ctx->path_nodes->len;
g_array_append_val (ctx->path_nodes, new_node);
g_array_index (ctx->path_nodes, CoglPathNode, ctx->last_path).path_size++;
if (ctx->path_nodes->len == 1)
{
ctx->path_nodes_min.x = ctx->path_nodes_max.x = x;
ctx->path_nodes_min.y = ctx->path_nodes_max.y = y;
}
else
{
if (x < ctx->path_nodes_min.x) ctx->path_nodes_min.x = x;
if (x > ctx->path_nodes_max.x) ctx->path_nodes_max.x = x;
if (y < ctx->path_nodes_min.y) ctx->path_nodes_min.y = y;
if (y > ctx->path_nodes_max.y) ctx->path_nodes_max.y = y;
}
}
void
_cogl_path_stroke_nodes ()
{
guint path_start = 0;
_COGL_GET_CONTEXT (ctx, NO_RETVAL);
cogl_enable (COGL_ENABLE_VERTEX_ARRAY
| (ctx->color_alpha < 255
? COGL_ENABLE_BLEND : 0));
while (path_start < ctx->path_nodes->len)
{
CoglPathNode *path = &g_array_index (ctx->path_nodes, CoglPathNode,
path_start);
GE( glVertexPointer (2, GL_FLOAT, sizeof (CoglPathNode),
(guchar *) path
+ G_STRUCT_OFFSET (CoglPathNode, x)) );
GE( glDrawArrays (GL_LINE_STRIP, 0, path->path_size) );
path_start += path->path_size;
}
}
static void
_cogl_path_get_bounds (floatVec2 nodes_min,
floatVec2 nodes_max,
float *bounds_x,
float *bounds_y,
float *bounds_w,
float *bounds_h)
{
*bounds_x = nodes_min.x;
*bounds_y = nodes_min.y;
*bounds_w = nodes_max.x - *bounds_x;
*bounds_h = nodes_max.y - *bounds_y;
}
void
_cogl_add_path_to_stencil_buffer (floatVec2 nodes_min,
floatVec2 nodes_max,
guint path_size,
CoglPathNode *path,
gboolean merge)
{
guint path_start = 0;
guint sub_path_num = 0;
float bounds_x;
float bounds_y;
float bounds_w;
float bounds_h;
_cogl_path_get_bounds (nodes_min, nodes_max,
&bounds_x, &bounds_y, &bounds_w, &bounds_h);
if (merge)
{
GE( glStencilMask (2) );
GE( glStencilFunc (GL_LEQUAL, 0x2, 0x6) );
}
else
{
GE( glClear (GL_STENCIL_BUFFER_BIT) );
GE( glStencilMask (1) );
GE( glStencilFunc (GL_LEQUAL, 0x1, 0x3) );
}
GE( glEnable (GL_STENCIL_TEST) );
GE( glStencilOp (GL_INVERT, GL_INVERT, GL_INVERT) );
GE( glColorMask (FALSE, FALSE, FALSE, FALSE) );
GE( glDepthMask (FALSE) );
while (path_start < path_size)
{
cogl_enable (COGL_ENABLE_VERTEX_ARRAY);
GE( glVertexPointer (2, GL_FLOAT, sizeof (CoglPathNode),
(guchar *) path
+ G_STRUCT_OFFSET (CoglPathNode, x)) );
GE( glDrawArrays (GL_TRIANGLE_FAN, 0, path->path_size) );
if (sub_path_num > 0)
{
/* Union the two stencil buffers bits into the least
significant bit */
GE( glStencilMask (merge ? 6 : 3) );
GE( glStencilOp (GL_ZERO, GL_REPLACE, GL_REPLACE) );
cogl_rectangle (bounds_x, bounds_y, bounds_w, bounds_h);
GE( glStencilOp (GL_INVERT, GL_INVERT, GL_INVERT) );
}
GE( glStencilMask (merge ? 4 : 2) );
path_start += path->path_size;
path += path->path_size;
sub_path_num++;
}
if (merge)
{
/* Now we have the new stencil buffer in bit 1 and the old
stencil buffer in bit 0 so we need to intersect them */
GE( glStencilMask (3) );
GE( glStencilFunc (GL_NEVER, 0x2, 0x3) );
GE( glStencilOp (GL_DECR, GL_DECR, GL_DECR) );
/* Decrement all of the bits twice so that only pixels where the
value is 3 will remain */
GE( glPushMatrix () );
GE( glLoadIdentity () );
GE( glMatrixMode (GL_PROJECTION) );
GE( glPushMatrix () );
GE( glLoadIdentity () );
GE( glRecti (-1, 1, 1, -1) );
GE( glRecti (-1, 1, 1, -1) );
GE( glPopMatrix () );
GE( glMatrixMode (GL_MODELVIEW) );
GE( glPopMatrix () );
}
GE( glStencilMask (~(GLuint) 0) );
GE( glDepthMask (TRUE) );
GE( glColorMask (TRUE, TRUE, TRUE, TRUE) );
GE( glStencilFunc (GL_EQUAL, 0x1, 0x1) );
GE( glStencilOp (GL_KEEP, GL_KEEP, GL_KEEP) );
}
void
_cogl_path_fill_nodes ()
{
float bounds_x;
float bounds_y;
float bounds_w;
float bounds_h;
_COGL_GET_CONTEXT (ctx, NO_RETVAL);
_cogl_add_path_to_stencil_buffer (ctx->path_nodes_min,
ctx->path_nodes_max,
ctx->path_nodes->len,
&g_array_index (ctx->path_nodes,
CoglPathNode, 0),
ctx->clip.stencil_used);
_cogl_path_get_bounds (ctx->path_nodes_min, ctx->path_nodes_max,
&bounds_x, &bounds_y, &bounds_w, &bounds_h);
cogl_rectangle (bounds_x, bounds_y, bounds_w, bounds_h);
/* The stencil buffer now contains garbage so the clip area needs to
be rebuilt */
ctx->clip.stack_dirty = TRUE;
}