brl/mutter
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

Bug 1189 - Backface culling

Browse Source 
* clutter/cogl/gl/cogl-texture.c (cogl_texture_polygon)
	(_cogl_texture_quad_sw, _cogl_texture_quad_hw):
	* clutter/cogl/gles/cogl-texture.c (cogl_texture_polygon)
	(_cogl_texture_quad_sw, _cogl_texture_quad_hw): Enable backface
	culling in GL if it is requested.

	* clutter/cogl/gles/cogl-texture.c (_cogl_texture_quad_sw)
	(_cogl_texture_quad_hw):
	* clutter/cogl/gl/cogl-texture.c (_cogl_texture_quad_sw)
	(_cogl_texture_quad_hw): Reorder the
	vertices so that they are counter-clockwise.

	* clutter/cogl/gles/cogl-context.h (CoglContext): 
	* clutter/cogl/gl/cogl-context.h (CoglContext): Added a flag to
	store whether backface culling is currently enabled.

	* clutter/cogl/gles/cogl.c (cogl_enable_backface_culling): 
	* clutter/cogl/gl/cogl.c (cogl_enable_backface_culling): New
	function

	* doc/reference/cogl/cogl-sections.txt: Add
	cogl_enable_backface_culling
This commit is contained in:
Neil Roberts 2008-10-27 14:36:52 +00:00
parent c8b4de2d6d
commit 153f5ea73f
10 changed files with 110 additions and 44 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

12
cogl.h.in
View File

@ -579,6 +579,18 @@ void cogl_clip_stack_restore (void);
*/
void cogl_enable_depth_test (gboolean setting);
/**
* cogl_enable_backface_culling:
* @setting: %TRUE to enable backface culling or %FALSE to disable.
*
* Sets whether textures positioned so that their backface is showing
* should be hidden. This can be used to efficiently draw two-sided
* textures or fully closed cubes without enabling depth testing. Only
* calls to cogl_texture_rectangle() and cogl_texture_polygon() are
* affected. Backface culling is disabled by default.
*/
void cogl_enable_backface_culling (gboolean setting);
/**
* cogl_alpha_func:
* @func: the comparison function to use, one of CGL_NEVER, CGL_LESS,

1
doc/reference/cogl/cogl-sections.txt
View File

@ -34,6 +34,7 @@ cogl_clip_stack_save
cogl_clip_stack_restore
<SUBSECTION>
cogl_enable_depth_test
cogl_enable_backface_culling
cogl_alpha_func
cogl_fog_set
</SECTION>

2
gl/cogl-context.h
View File

@ -40,6 +40,8 @@ typedef struct
guint8 color_alpha;
COGLenum blend_src_factor;
COGLenum blend_dst_factor;
gboolean enable_backface_culling;
/* Primitives */
CoglFixedVec2 path_start;

1
gl/cogl-internal.h
View File

@ -56,6 +56,7 @@ const char *_cogl_error_string(GLenum errorCode);
#define COGL_ENABLE_TEXTURE_RECT (1<<4)
#define COGL_ENABLE_VERTEX_ARRAY (1<<5)
#define COGL_ENABLE_TEXCOORD_ARRAY (1<<6)
#define COGL_ENABLE_BACKFACE_CULLING (1<<7)
gint
_cogl_get_format_bpp (CoglPixelFormat format);

58
gl/cogl-texture.c
View File

@ -1949,6 +1949,9 @@ _cogl_texture_quad_sw (CoglTexture *tex,
{
enable_flags |= COGL_ENABLE_BLEND;
}
if (ctx->enable_backface_culling)
enable_flags |= COGL_ENABLE_BACKFACE_CULLING;
cogl_enable (enable_flags);
@ -2050,21 +2053,21 @@ _cogl_texture_quad_sw (CoglTexture *tex,
/* Draw textured quad */
glBegin (GL_QUADS);
glTexCoord2f (CFX_F(slice_tx1), CFX_F(slice_ty1));
glVertex2f (CFX_F(slice_qx1), CFX_F(slice_qy1));
glTexCoord2f (CFX_F(slice_tx2), CFX_F(slice_ty1));
glVertex2f (CFX_F(slice_qx2), CFX_F(slice_qy1));
glTexCoord2f (CFX_F(slice_tx2), CFX_F(slice_ty2));
glVertex2f (CFX_F(slice_qx2), CFX_F(slice_qy2));
glTexCoord2f (CFX_F(slice_tx1), CFX_F(slice_ty2));
glVertex2f (CFX_F(slice_qx1), CFX_F(slice_qy2));
glTexCoord2f (CFX_F(slice_tx2), CFX_F(slice_ty2));
glVertex2f (CFX_F(slice_qx2), CFX_F(slice_qy2));
glTexCoord2f (CFX_F(slice_tx2), CFX_F(slice_ty1));
glVertex2f (CFX_F(slice_qx2), CFX_F(slice_qy1));
GE( glEnd () );
#undef CFX_F
}
}
@ -2101,6 +2104,9 @@ _cogl_texture_quad_hw (CoglTexture *tex,
enable_flags |= COGL_ENABLE_BLEND;
}
if (ctx->enable_backface_culling)
enable_flags |= COGL_ENABLE_BACKFACE_CULLING;
cogl_enable (enable_flags);
/* Pick and bind opengl texture object */
@ -2117,24 +2123,24 @@ _cogl_texture_quad_hw (CoglTexture *tex,
ty2 = ty2 * (y_span->size - y_span->waste) / y_span->size;
#define CFX_F(x) CLUTTER_FIXED_TO_FLOAT(x)
/* Draw textured quad */
glBegin (GL_QUADS);
glTexCoord2f (CFX_F(tx1), CFX_F(ty1));
glVertex2f (CFX_F(x1), CFX_F(y1));
glTexCoord2f (CFX_F(tx2), CFX_F(ty1));
glVertex2f (CFX_F(x2), CFX_F(y1));
glTexCoord2f (CFX_F(tx2), CFX_F(ty2));
glVertex2f (CFX_F(x2), CFX_F(y2));
glTexCoord2f (CFX_F(tx1), CFX_F(ty2));
glVertex2f (CFX_F(x1), CFX_F(y2));
glTexCoord2f (CFX_F(tx2), CFX_F(ty2));
glVertex2f (CFX_F(x2), CFX_F(y2));
glTexCoord2f (CFX_F(tx2), CFX_F(ty1));
glVertex2f (CFX_F(x2), CFX_F(y1));
GE( glEnd () );
#undef CFX_F
}
@ -2231,6 +2237,9 @@ cogl_texture_polygon (CoglHandle handle,
int i, x, y, vnum;
GLuint gl_handle;
CoglTexSliceSpan *y_span, *x_span;
gulong enable_flags;
_COGL_GET_CONTEXT (ctx, NO_RETVAL);
/* Check if valid texture */
if (!cogl_is_texture (handle))
@ -2261,7 +2270,12 @@ cogl_texture_polygon (CoglHandle handle,
tex = _cogl_texture_pointer_from_handle (handle);
/* Prepare GL state */
cogl_enable (COGL_ENABLE_TEXTURE_2D | COGL_ENABLE_BLEND);
enable_flags = COGL_ENABLE_TEXTURE_2D | COGL_ENABLE_BLEND;
if (ctx->enable_backface_culling)
enable_flags |= COGL_ENABLE_BACKFACE_CULLING;
cogl_enable (enable_flags);
/* Temporarily change the wrapping mode on all of the slices to use
a transparent border */

12
gl/cogl.c
View File

@ -314,6 +314,10 @@ cogl_enable (gulong flags)
cogl_toggle_flag (ctx, flags,
COGL_ENABLE_TEXTURE_2D,
GL_TEXTURE_2D);
cogl_toggle_flag (ctx, flags,
COGL_ENABLE_BACKFACE_CULLING,
GL_CULL_FACE);
cogl_toggle_client_flag (ctx, flags,
COGL_ENABLE_VERTEX_ARRAY,
@ -367,6 +371,14 @@ cogl_enable_depth_test (gboolean setting)
}
}
void
cogl_enable_backface_culling (gboolean setting)
{
_COGL_GET_CONTEXT (ctx, NO_RETVAL);
ctx->enable_backface_culling = setting;
}
void
cogl_color (const ClutterColor *color)
{

2
gles/cogl-context.h
View File

@ -49,6 +49,8 @@ typedef struct
guint8 color_alpha;
COGLenum blend_src_factor;
COGLenum blend_dst_factor;
gboolean enable_backface_culling;
/* Primitives */
CoglFixedVec2 path_start;

1
gles/cogl-internal.h
View File

@ -57,6 +57,7 @@ const char *_cogl_error_string(GLenum errorCode);
#define COGL_ENABLE_VERTEX_ARRAY (1<<5)
#define COGL_ENABLE_TEXCOORD_ARRAY (1<<6)
#define COGL_ENABLE_COLOR_ARRAY (1<<7)
#define COGL_ENABLE_BACKFACE_CULLING (1<<8)
gint
_cogl_get_format_bpp (CoglPixelFormat format);

51
gles/cogl-texture.c
View File

@ -1924,6 +1924,9 @@ _cogl_texture_quad_sw (CoglTexture *tex,
enable_flags |= COGL_ENABLE_BLEND;
}
if (ctx->enable_backface_culling)
enable_flags |= COGL_ENABLE_BACKFACE_CULLING;
cogl_enable (enable_flags);
GE( cogl_wrap_glTexCoordPointer (2, GL_FIXED, 0, tex_coords) );
@ -2021,18 +2024,18 @@ _cogl_texture_quad_sw (CoglTexture *tex,
GE( cogl_gles2_wrapper_bind_texture (tex->gl_target, gl_handle,
tex->gl_intformat) );
/* Draw textured quad */
tex_coords[0] = slice_tx1; tex_coords[1] = slice_ty1;
tex_coords[2] = slice_tx2; tex_coords[3] = slice_ty1;
tex_coords[4] = slice_tx1; tex_coords[5] = slice_ty2;
tex_coords[6] = slice_tx2; tex_coords[7] = slice_ty2;
quad_coords[0] = slice_qx1; quad_coords[1] = slice_qy1;
quad_coords[2] = slice_qx2; quad_coords[3] = slice_qy1;
quad_coords[4] = slice_qx1; quad_coords[5] = slice_qy2;
quad_coords[6] = slice_qx2; quad_coords[7] = slice_qy2;
tex_coords[0] = slice_tx1; tex_coords[1] = slice_ty2;
tex_coords[2] = slice_tx2; tex_coords[3] = slice_ty2;
tex_coords[4] = slice_tx1; tex_coords[5] = slice_ty1;
tex_coords[6] = slice_tx2; tex_coords[7] = slice_ty1;
quad_coords[0] = slice_qx1; quad_coords[1] = slice_qy2;
quad_coords[2] = slice_qx2; quad_coords[3] = slice_qy2;
quad_coords[4] = slice_qx1; quad_coords[5] = slice_qy1;
quad_coords[6] = slice_qx2; quad_coords[7] = slice_qy1;
GE (cogl_wrap_glDrawArrays (GL_TRIANGLE_STRIP, 0, 4) );
}
}
@ -2071,6 +2074,9 @@ _cogl_texture_quad_hw (CoglTexture *tex,
enable_flags |= COGL_ENABLE_BLEND;
}
if (ctx->enable_backface_culling)
enable_flags |= COGL_ENABLE_BACKFACE_CULLING;
cogl_enable (enable_flags);
GE( cogl_wrap_glTexCoordPointer (2, GL_FIXED, 0, tex_coords) );
@ -2090,16 +2096,16 @@ _cogl_texture_quad_hw (CoglTexture *tex,
ty2 = ty2 * (y_span->size - y_span->waste) / y_span->size;
/* Draw textured quad */
tex_coords[0] = tx1; tex_coords[1] = ty1;
tex_coords[2] = tx2; tex_coords[3] = ty1;
tex_coords[4] = tx1; tex_coords[5] = ty2;
tex_coords[6] = tx2; tex_coords[7] = ty2;
quad_coords[0] = x1; quad_coords[1] = y1;
quad_coords[2] = x2; quad_coords[3] = y1;
quad_coords[4] = x1; quad_coords[5] = y2;
quad_coords[6] = x2; quad_coords[7] = y2;
tex_coords[0] = tx1; tex_coords[1] = ty2;
tex_coords[2] = tx2; tex_coords[3] = ty2;
tex_coords[4] = tx1; tex_coords[5] = ty1;
tex_coords[6] = tx2; tex_coords[7] = ty1;
quad_coords[0] = x1; quad_coords[1] = y2;
quad_coords[2] = x2; quad_coords[3] = y2;
quad_coords[4] = x1; quad_coords[5] = y1;
quad_coords[6] = x2; quad_coords[7] = y1;
GE (cogl_wrap_glDrawArrays (GL_TRIANGLE_STRIP, 0, 4) );
}
@ -2258,6 +2264,9 @@ cogl_texture_polygon (CoglHandle handle,
else if (ctx->color_alpha < 255)
enable_flags |= COGL_ENABLE_BLEND;
if (ctx->enable_backface_culling)
enable_flags |= COGL_ENABLE_BACKFACE_CULLING;
if (use_color)
{
enable_flags |= COGL_ENABLE_COLOR_ARRAY;

14
gles/cogl.c
View File

@ -222,7 +222,11 @@ cogl_enable (gulong flags)
cogl_toggle_flag (ctx, flags,
COGL_ENABLE_TEXTURE_2D,
GL_TEXTURE_2D);
cogl_toggle_flag (ctx, flags,
COGL_ENABLE_BACKFACE_CULLING,
GL_CULL_FACE);
cogl_toggle_client_flag (ctx, flags,
COGL_ENABLE_VERTEX_ARRAY,
GL_VERTEX_ARRAY);
@ -278,6 +282,14 @@ cogl_enable_depth_test (gboolean setting)
}
}
void
cogl_enable_backface_culling (gboolean setting)
{
_COGL_GET_CONTEXT (ctx, NO_RETVAL);
ctx->enable_backface_culling = setting;
}
void
cogl_color (const ClutterColor *color)
{