mutter/cogl/cogl-internal.h
Robert Bragg 181bf92086 [cogl] Use clockwise face winding for offscreen buffers with culling enabled
Because Cogl defines the origin for texture as top left and offscreen draw
buffers can be used to render to textures, we (internally) force all
offscreen rendering to be upside down. (because OpenGL defines the origin
to be bottom left)

By forcing the users scene to be rendered upside down though we also reverse
the winding order of all the drawn triangles which may interfere with the
users use of backface culling.  This patch ensures that we reverse the
winding order for a front face (if culling is in use) while rendering
offscreen so we don't conflict with the users back face culling.
2009-11-04 03:34:03 +00:00

118 lines
3.0 KiB
C

/*
* Cogl
*
* An object oriented GL/GLES Abstraction/Utility Layer
*
* Copyright (C) 2007,2008,2009 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, write to the
* Free Software Foundation, Inc., 59 Temple Place - Suite 330,
* Boston, MA 02111-1307, USA.
*/
#ifndef __COGL_INTERNAL_H
#define __COGL_INTERNAL_H
#include "cogl.h"
#include "cogl-matrix-stack.h"
typedef enum
{
COGL_MATRIX_MODELVIEW,
COGL_MATRIX_PROJECTION,
COGL_MATRIX_TEXTURE
} CoglMatrixMode;
typedef enum
{
COGL_FRONT_WINDING_CLOCKWISE,
COGL_FRONT_WINDING_COUNTER_CLOCKWISE
} CoglFrontWinding;
#ifdef HAVE_COGL_GLES2
typedef enum {
COGL_BOXED_NONE,
COGL_BOXED_INT,
COGL_BOXED_FLOAT,
COGL_BOXED_MATRIX
} CoglBoxedType;
typedef struct _CoglBoxedValue
{
CoglBoxedType type;
int size, count;
gboolean transpose;
union {
gfloat float_value[4];
gint int_value[4];
gfloat matrix[16];
gfloat *float_array;
gint *int_array;
gpointer array;
} v;
} CoglBoxedValue;
#endif
#ifdef COGL_GL_DEBUG
const gchar *cogl_gl_error_to_string (GLenum error_code);
#define GE(x...) G_STMT_START { \
GLenum __err; \
(x); \
while ((__err = glGetError ()) != GL_NO_ERROR) \
{ \
g_warning ("%s: GL error (%d): %s\n", \
G_STRLOC, \
__err, \
cogl_gl_error_to_string (__err)); \
} } G_STMT_END
#else /* !COGL_GL_DEBUG */
#define GE(x) (x)
#endif /* COGL_GL_DEBUG */
#define COGL_ENABLE_BLEND (1<<1)
#define COGL_ENABLE_ALPHA_TEST (1<<2)
#define COGL_ENABLE_VERTEX_ARRAY (1<<3)
#define COGL_ENABLE_COLOR_ARRAY (1<<4)
#define COGL_ENABLE_BACKFACE_CULLING (1<<5)
void _cogl_features_init (void);
gint _cogl_get_format_bpp (CoglPixelFormat format);
void cogl_enable (gulong flags);
gulong cogl_get_enable (void);
typedef struct _CoglTextureUnit
{
int index;
CoglMatrixStack *matrix_stack;
} CoglTextureUnit;
CoglTextureUnit *
_cogl_get_texture_unit (int index_);
void
_cogl_destroy_texture_units (void);
void _cogl_flush_matrix_stacks (void);
void
_cogl_flush_face_winding (void);
#endif /* __COGL_INTERNAL_H */