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COGL 0.9.2 Reference Manual | ![]() |
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Top | Description |
#define COGL_INVALID_HANDLE typedef CoglHandle; void (*CoglFuncPtr) (void); #define COGL_PIXEL_FORMAT_24 #define COGL_PIXEL_FORMAT_32 #define COGL_A_BIT #define COGL_BGR_BIT #define COGL_AFIRST_BIT #define COGL_PREMULT_BIT #define COGL_UNORDERED_MASK #define COGL_UNPREMULT_MASK enum CoglPixelFormat; enum CoglBufferTarget; gboolean cogl_create_context (void); void cogl_destroy_context (void); enum CoglFeatureFlags; CoglFeatureFlags cogl_get_features (void); gboolean cogl_features_available (CoglFeatureFlags features); gboolean cogl_check_extension (const gchar *name, const gchar *ext); CoglFuncPtr cogl_get_proc_address (const gchar *name); void cogl_perspective (float fovy, float aspect, float z_near, float z_far); void cogl_frustum (float left, float right, float bottom, float top, float z_near, float z_far); void cogl_setup_viewport (guint width, guint height, float fovy, float aspect, float z_near, float z_far); void cogl_viewport (guint width, guint height); void cogl_get_modelview_matrix (CoglMatrix *matrix); void cogl_get_projection_matrix (CoglMatrix *matrix); void cogl_get_viewport (float v[4]); void cogl_push_matrix (void); void cogl_pop_matrix (void); void cogl_scale (float x, float y, float z); void cogl_translate (float x, float y, float z); void cogl_rotate (float angle, float x, float y, float z); void cogl_clear (const CoglColor *color); void cogl_get_bitmasks (gint *red, gint *green, gint *blue, gint *alpha); void cogl_enable_depth_test (gboolean setting); void cogl_enable_backface_culling (gboolean setting); enum CoglFogMode; void cogl_set_fog (const CoglColor *fog_color, CoglFogMode mode, float density, float z_near, float z_far); void cogl_disable_fog (void); void cogl_set_source (CoglHandle material); void cogl_set_source_color (const CoglColor *color); void cogl_set_source_color4ub (guint8 red, guint8 green, guint8 blue, guint8 alpha); void cogl_set_source_color4f (float red, float green, float blue, float alpha); void cogl_set_source_texture (CoglHandle texture_handle);
#define COGL_INVALID_HANDLE NULL
A COGL handle that is not valid, used for unitialized handles as well as error conditions.
typedef gpointer CoglHandle;
Type used for storing references to cogl objects, the CoglHandle is a fully opaque type without any public data members.
void (*CoglFuncPtr) (void);
The type used by cogl for function pointers, note that this type is used as a generic catch-all cast for function pointers and the actual arguments and return type may be different.
typedef enum { COGL_PIXEL_FORMAT_ANY = 0, COGL_PIXEL_FORMAT_A_8 = 1 | COGL_A_BIT, COGL_PIXEL_FORMAT_RGB_565 = 4, COGL_PIXEL_FORMAT_RGBA_4444 = 5 | COGL_A_BIT, COGL_PIXEL_FORMAT_RGBA_5551 = 6 | COGL_A_BIT, COGL_PIXEL_FORMAT_YUV = 7, COGL_PIXEL_FORMAT_G_8 = 8, COGL_PIXEL_FORMAT_RGB_888 = COGL_PIXEL_FORMAT_24, COGL_PIXEL_FORMAT_BGR_888 = (COGL_PIXEL_FORMAT_24 | COGL_BGR_BIT), COGL_PIXEL_FORMAT_RGBA_8888 = COGL_PIXEL_FORMAT_32 | COGL_A_BIT, COGL_PIXEL_FORMAT_BGRA_8888 = (COGL_PIXEL_FORMAT_32 | COGL_A_BIT | COGL_BGR_BIT), COGL_PIXEL_FORMAT_ARGB_8888 = (COGL_PIXEL_FORMAT_32 | COGL_A_BIT | COGL_AFIRST_BIT), COGL_PIXEL_FORMAT_ABGR_8888 = (COGL_PIXEL_FORMAT_32 | COGL_A_BIT | COGL_BGR_BIT | COGL_AFIRST_BIT), COGL_PIXEL_FORMAT_RGBA_8888_PRE = (COGL_PIXEL_FORMAT_32 | COGL_A_BIT | COGL_PREMULT_BIT), COGL_PIXEL_FORMAT_BGRA_8888_PRE = (COGL_PIXEL_FORMAT_32 | COGL_A_BIT | COGL_PREMULT_BIT | COGL_BGR_BIT), COGL_PIXEL_FORMAT_ARGB_8888_PRE = (COGL_PIXEL_FORMAT_32 | COGL_A_BIT | COGL_PREMULT_BIT | COGL_AFIRST_BIT), COGL_PIXEL_FORMAT_ABGR_8888_PRE = (COGL_PIXEL_FORMAT_32 | COGL_A_BIT | COGL_PREMULT_BIT | COGL_BGR_BIT | COGL_AFIRST_BIT), COGL_PIXEL_FORMAT_RGBA_4444_PRE = (COGL_PIXEL_FORMAT_RGBA_4444 | COGL_A_BIT | COGL_PREMULT_BIT), COGL_PIXEL_FORMAT_RGBA_5551_PRE = (COGL_PIXEL_FORMAT_RGBA_5551 | COGL_A_BIT | COGL_PREMULT_BIT), } CoglPixelFormat;
Pixel formats used by COGL.
Any format | |
8 bits alpha mask | |
RGB, 16 bits | |
RGBA, 16 bits | |
RGBA, 16 bits | |
FIXME | |
FIXME | |
RGB, 24 bits | |
BGR, 24 bits | |
RGBA, 32 bits | |
BGRA, 32 bits | |
ARGB, 32 bits | |
ABGR, 32 bits | |
Premultiplied RGBA, 32 bits | |
Premultiplied BGRA, 32 bits | |
Premultiplied ARGB, 32 bits | |
Premultiplied ABGR, 32 bits | |
Premultiplied RGBA, 16 bits | |
Premultiplied RGBA, 16 bits |
Since 0.8
typedef enum { COGL_WINDOW_BUFFER = (1 << 1), COGL_MASK_BUFFER = (1 << 2), COGL_OFFSCREEN_BUFFER = (1 << 3) } CoglBufferTarget;
Target flags for FBOs.
Since 0.8
typedef enum { COGL_FEATURE_TEXTURE_RECTANGLE = (1 << 1), COGL_FEATURE_TEXTURE_NPOT = (1 << 2), COGL_FEATURE_TEXTURE_YUV = (1 << 3), COGL_FEATURE_TEXTURE_READ_PIXELS = (1 << 4), COGL_FEATURE_SHADERS_GLSL = (1 << 5), COGL_FEATURE_OFFSCREEN = (1 << 6), COGL_FEATURE_OFFSCREEN_MULTISAMPLE = (1 << 7), COGL_FEATURE_OFFSCREEN_BLIT = (1 << 8), COGL_FEATURE_FOUR_CLIP_PLANES = (1 << 9), COGL_FEATURE_STENCIL_BUFFER = (1 << 10), COGL_FEATURE_VBOS = (1 << 11) } CoglFeatureFlags;
Flags for the supported features.
ARB_texture_rectangle support | |
ARB_texture_non_power_of_two support | |
ycbcr conversion support | |
glReadPixels() support
|
|
GLSL support | |
FBO support | |
Multisample support on FBOs | |
Blit support on FBOs | |
At least 4 clip planes available | |
Stencil buffer support | |
VBO support |
Since 0.8
CoglFeatureFlags cogl_get_features (void);
Returns all of the features supported by COGL.
Returns : |
A logical OR of all the supported COGL features. |
Since 0.8
gboolean cogl_features_available (CoglFeatureFlags features);
Checks whether the given COGL features are available. Multiple
features can be checked for by or-ing them together with the '|'
operator. TRUE
is only returned if all of the requested features
are available.
|
A bitmask of features to check for |
Returns : |
TRUE if the features are available, FALSE otherwise.
|
gboolean cogl_check_extension (const gchar *name, const gchar *ext);
Check whether name
occurs in list of extensions in ext
.
|
extension to check for |
|
list of extensions |
Returns : |
TRUE if the extension occurs in the list, FALSE otherwize.
|
CoglFuncPtr cogl_get_proc_address (const gchar *name);
Gets a pointer to a given GL or GL ES extension function. This acts
as a wrapper around glXGetProcAddress()
or whatever is the
appropriate function for the current backend.
|
the name of the function. |
Returns : |
a pointer to the requested function or NULL if the
function is not available.
|
void cogl_perspective (float fovy, float aspect, float z_near, float z_far);
Replaces the current projection matrix with a perspective matrix based on the provided values.
|
Vertical of view angle in degrees. |
|
Aspect ratio of diesplay |
|
Nearest visible point |
|
Furthest visible point along the z-axis |
void cogl_frustum (float left, float right, float bottom, float top, float z_near, float z_far);
Replaces the current projection matrix with a perspective matrix for the given viewing frustum.
|
Left clipping plane |
|
Right clipping plane |
|
Bottom clipping plane |
|
Top clipping plane |
|
Nearest visible point |
|
Furthest visible point along the z-axis |
Since 0.8.2
void cogl_setup_viewport (guint width, guint height, float fovy, float aspect, float z_near, float z_far);
Replaces the current viewport and projection matrix with the given
values. The viewport is placed at the top left corner of the window
with the given width and height. The projection matrix is replaced
with one that has a viewing angle of fovy
along the y-axis and a
view scaled according to aspect
along the x-axis. The view is
clipped according to z_near
and z_far
on the z-axis.
|
Width of the viewport |
|
Height of the viewport |
|
Field of view angle in degrees |
|
Aspect ratio to determine the field of view along the x-axis |
|
Nearest visible point along the z-axis |
|
Furthest visible point along the z-axis |
void cogl_viewport (guint width, guint height);
Replace the current viewport with the given values.
|
Width of the viewport |
|
Height of the viewport |
Since 0.8.2
void cogl_get_modelview_matrix (CoglMatrix *matrix);
Stores the current model-view matrix in matrix
.
|
pointer to a CoglMatrix to recieve the matrix |
void cogl_get_projection_matrix (CoglMatrix *matrix);
Stores the current projection matrix in matrix
.
|
pointer to a CoglMatrix to recieve the matrix |
void cogl_get_viewport (float v[4]);
Stores the current viewport in v
. v
[0] and v
[1] get the x and y
position of the viewport and v
[2] and v
[3] get the width and
height.
|
pointer to a 4 element array of floats to receive the viewport dimensions. |
void cogl_push_matrix (void);
Store the current model-view matrix on the matrix stack. The matrix
can later be restored with cogl_pop_matrix()
.
void cogl_pop_matrix (void);
Restore the current model-view matrix from the matrix stack.
void cogl_scale (float x, float y, float z);
Multiplies the current model-view matrix by one that scales the x, y and z axes by the given values.
|
Amount to scale along the x-axis |
|
Amount to scale along the y-axis |
|
Amount to scale along the z-axis |
void cogl_translate (float x, float y, float z);
Multiplies the current model-view matrix by one that translates the model along all three axes according to the given values.
|
Distance to translate along the x-axis |
|
Distance to translate along the y-axis |
|
Distance to translate along the z-axis |
void cogl_rotate (float angle, float x, float y, float z);
Multiplies the current model-view matrix by one that rotates the
model around the vertex specified by x
, y
and z
. The rotation
follows the right-hand thumb rule so for example rotating by 10
degrees about the vertex (0, 0, 1) causes a small counter-clockwise
rotation.
|
Angle in degrees to rotate. |
|
X-component of vertex to rotate around. |
|
Y-component of vertex to rotate around. |
|
Z-component of vertex to rotate around. |
void cogl_clear (const CoglColor *color);
Clears the color buffer to color
. The depth buffer and stencil
buffers are also cleared.
|
Background color to clear to |
void cogl_get_bitmasks (gint *red, gint *green, gint *blue, gint *alpha);
Gets the number of bitplanes used for each of the color components
in the color buffer. Pass NULL
for any of the arguments if the
value is not required.
|
Return location for the number of red bits or NULL
|
|
Return location for the number of green bits or NULL
|
|
Return location for the number of blue bits or NULL
|
|
Return location for the number of alpha bits or NULL
|
void cogl_enable_depth_test (gboolean setting);
Sets whether depth testing is enabled. If it is disabled then the
order that actors are layered on the screen depends solely on the
order specified using clutter_actor_raise()
and
clutter_actor_lower()
, otherwise it will also take into account the
actor's depth. Depth testing is disabled by default.
|
TRUE to enable depth testing or FALSE to disable.
|
void cogl_enable_backface_culling (gboolean setting);
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.
|
TRUE to enable backface culling or FALSE to disable.
|
typedef enum _CoglFogMode { COGL_FOG_MODE_LINEAR, COGL_FOG_MODE_EXPONENTIAL, COGL_FOG_MODE_EXPONENTIAL_SQUARED } CoglFogMode;
The fog mode determines the equation used to calculate the fogging blend
factor while fogging is enabled. The simplest COGL_FOG_MODE_LINEAR
mode
determines f as:
f = end - eye_distance / end - start
Where eye_distance is the distance of the current fragment in eye coordinates from the origin.
Calculates the fog blend factor as:
f = end - eye_distance / end - start |
|
Calculates the fog blend factor as:
f = e ^ -(density * eye_distance) |
|
Calculates the fog blend factor as:
f = e ^ -(density * eye_distance)^2 |
Since 1.0
void cogl_set_fog (const CoglColor *fog_color, CoglFogMode mode, float density, float z_near, float z_far);
Enables fogging. Fogging causes vertices that are further away from
the eye to be rendered with a different color. The color is determined
according to the chosen fog mode; at it's simplest the color is
linearly interpolated so that vertices at z_near
are drawn fully
with their original color and vertices at z_far
are drawn fully
with fog_color
. Fogging will remain enabled until you call
cogl_disable_fog()
.
|
The color of the fog |
|
A CoglFogMode that determines the equation used to calculate the fogging blend factor. |
|
Used by the EXPONENTIAL and EXPONENTIAL_SQUARED CoglFogMode equations. |
|
Position along z-axis where no fogging should be applied |
|
Position along z-axes where full fogging should be applied |
void cogl_disable_fog (void);
This function disables fogging, so primitives drawn afterwards will not be blended with any previously set fog color.
void cogl_set_source (CoglHandle material);
This function sets the source material that will be used to fill subsequent geometry emitted via the cogl API.
Note: in the future we may add the ability to set a front facing material, and a back facing material, in which case this function will set both to the same.
Since 1.0
|
A CoglMaterial object |
void cogl_set_source_color (const CoglColor *color);
Sets the source color using normalized values for each component. This color will be used for any subsequent drawing operation.
See also cogl_set_source_color4ub()
and cogl_set_source_color4f()
if you already have the color components.
|
a CoglColor |
Since 1.0
void cogl_set_source_color4ub (guint8 red, guint8 green, guint8 blue, guint8 alpha);
This is a convenience function for creating a solid fill source material from the given color using unsigned bytes for each component. This color will be used for any subsequent drawing operation.
The value for each component is an unsigned byte in the range between 0 and 255.
|
value of the red channel, between 0 and 255 |
|
value of the green channel, between 0 and 255 |
|
value of the blue channel, between 0 and 255 |
|
value of the alpha channel, between 0 and 255 |
Since 1.0
void cogl_set_source_color4f (float red, float green, float blue, float alpha);
This is a convenience function for creating a solid fill source material from the given color using normalized values for each component. This color will be used for any subsequent drawing operation.
The value for each component is a fixed point number in the range
between 0 and 1
.0. If the values passed in are outside that
range, they will be clamped.
|
value of the red channel, between 0 and 1 .0
|
|
value of the green channel, between 0 and 1 .0
|
|
value of the blue channel, between 0 and 1 .0
|
|
value of the alpha channel, between 0 and 1 .0
|
Since 1.0
void cogl_set_source_texture (CoglHandle texture_handle);
This is a convenience function for creating a material with the first layer set to texture_handle and setting that material as the source with cogl_set_source.
Note: There is no interaction between calls to cogl_set_source_color and cogl_set_source_texture. If you need to blend a texture with a color then you can create a simple material like this:
material = cogl_material_new (); cogl_material_set_color4ub (material, 0xff, 0x00, 0x00, 0x80); cogl_material_set_layer (material, 0, tex_handle); cogl_set_source (material);
Since 1.0
|
The Cogl texture you want as your source |