mutter/cogl.h.in
Emmanuele Bassi 9e9c615e49 Add runtime debug messages for COGL
Clutter is able to show debug messages written using the CLUTTER_NOTE()
macro at runtime, either by using an environment variable:

  CLUTTER_DEBUG=...

or by using a command line switch:

  --clutter-debug=...
  --clutter-no-debug=...

Both are parsed during the initialization process by using the
GOption API.

COGL would benefit from having the same support.

In order to do this, we need a cogl_get_option_group() function in
COGL that sets up a GOptionGroup for COGL and adds a pre-parse hook
that will check the COGL_DEBUG environment variable. The OptionGroup
will also install two command line switches:

  --cogl-debug
  --cogl-no-debug

With the same semantics of the Clutter ones.

During Clutter initialization, the COGL option group will be attached
to the GOptionContext used to parse the command line options passed
to a Clutter application.

Every debug message written using:

  COGL_NOTE (SECTION, "message format", arguments);

Will then be printed only if SECTION was enabled at runtime.

This whole machinery, like the equivalent one in Clutter, depends on
a compile time switch, COGL_ENABLE_DEBUG, which is enabled at the same
time as CLUTTER_ENABLE_DEBUG. Having two different symbols allows
greater granularity.
2009-02-23 13:00:52 +00:00

604 lines
20 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.
*/
#ifndef __COGL_H__
#define __COGL_H__
#include <glib.h>
#define __COGL_H_INSIDE__
#include <cogl/cogl-defines-@CLUTTER_COGL@.h>
#include <cogl/cogl-vertex-buffer.h>
#include <cogl/cogl-matrix.h>
#include <cogl/cogl-vertex-buffer.h>
#include <cogl/cogl-fixed.h>
#include <cogl/cogl-color.h>
#include <cogl/cogl-offscreen.h>
#include <cogl/cogl-material.h>
#include <cogl/cogl-path.h>
#include <cogl/cogl-shader.h>
#include <cogl/cogl-texture.h>
#include <cogl/cogl-types.h>
#include <cogl/cogl-debug.h>
#include <cogl/cogl-deprecated.h>
G_BEGIN_DECLS
/**
* SECTION:cogl
* @short_description: General purpose API
*
* General utility functions for COGL.
*/
/* Context manipulation */
/**
* cogl_create_context:
*
* FIXME
*/
gboolean cogl_create_context (void);
/**
* cogl_destroy_context:
*
* FIXME
*/
void cogl_destroy_context (void);
/**
* cogl_get_option_group:
*
* Retrieves the #GOptionGroup used by COGL to parse the command
* line options. Clutter uses this to handle the COGL command line
* options during its initialization process.
*
* Return value: a #GOptionGroup
*
* Since: 1.0
*/
GOptionGroup * cogl_get_option_group (void);
/* Misc */
/**
* cogl_get_features:
*
* Returns all of the features supported by COGL.
*
* Return value: A logical OR of all the supported COGL features.
*
* Since: 0.8
*/
CoglFeatureFlags cogl_get_features (void);
/**
* cogl_features_available:
* @features: A bitmask of features to check for
*
* 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.
*
* Return value: %TRUE if the features are available, %FALSE otherwise.
*/
gboolean cogl_features_available (CoglFeatureFlags features);
/**
* cogl_get_proc_address:
* @name: the name of the function.
*
* 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.
*
* Return value: a pointer to the requested function or %NULL if the
* function is not available.
*/
CoglFuncPtr cogl_get_proc_address (const gchar *name);
/**
* cogl_check_extension:
* @name: extension to check for
* @ext: list of extensions
*
* Check whether @name occurs in list of extensions in @ext.
*
* Returns: %TRUE if the extension occurs in the list, %FALSE otherwize.
*/
gboolean cogl_check_extension (const gchar *name,
const gchar *ext);
/**
* cogl_get_bitmasks:
* @red: Return location for the number of red bits or %NULL
* @green: Return location for the number of green bits or %NULL
* @blue: Return location for the number of blue bits or %NULL
* @alpha: Return location for the number of alpha bits or %NULL
*
* 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.
*/
void cogl_get_bitmasks (gint *red,
gint *green,
gint *blue,
gint *alpha);
/**
* cogl_perspective:
* @fovy: Vertical of view angle in degrees.
* @aspect: Aspect ratio of diesplay
* @z_near: Nearest visible point
* @z_far: Furthest visible point along the z-axis
*
* Replaces the current projection matrix with a perspective matrix
* based on the provided values.
*/
void cogl_perspective (float fovy,
float aspect,
float z_near,
float z_far);
/**
* cogl_frustum:
* @left: Left clipping plane
* @right: Right clipping plane
* @bottom: Bottom clipping plane
* @top: Top clipping plane
* @z_near: Nearest visible point
* @z_far: Furthest visible point along the z-axis
*
* Replaces the current projection matrix with a perspective matrix
* for the given viewing frustum.
*
* Since: 0.8.2
*/
void cogl_frustum (float left,
float right,
float bottom,
float top,
float z_near,
float z_far);
/**
* cogl_setup_viewport:
* @width: Width of the viewport
* @height: Height of the viewport
* @fovy: Field of view angle in degrees
* @aspect: Aspect ratio to determine the field of view along the x-axis
* @z_near: Nearest visible point along the z-axis
* @z_far: Furthest visible point along the z-axis
*
* 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.
*/
void cogl_setup_viewport (guint width,
guint height,
float fovy,
float aspect,
float z_near,
float z_far);
/**
* cogl_viewport:
* @width: Width of the viewport
* @height: Height of the viewport
*
* Replace the current viewport with the given values.
*
* Since: 0.8.2
*/
void cogl_viewport (guint width,
guint height);
/**
* cogl_push_matrix:
*
* Store the current model-view matrix on the matrix stack. The matrix
* can later be restored with cogl_pop_matrix().
*/
void cogl_push_matrix (void);
/**
* cogl_pop_matrix:
*
* Restore the current model-view matrix from the matrix stack.
*/
void cogl_pop_matrix (void);
/**
* cogl_scale:
* @x: Amount to scale along the x-axis
* @y: Amount to scale along the y-axis
* @z: Amount to scale along the z-axis
*
* Multiplies the current model-view matrix by one that scales the x,
* y and z axes by the given values.
*/
void cogl_scale (float x,
float y,
float z);
/**
* cogl_translate:
* @x: Distance to translate along the x-axis
* @y: Distance to translate along the y-axis
* @z: Distance to translate along the z-axis
*
* Multiplies the current model-view matrix by one that translates the
* model along all three axes according to the given values.
*/
void cogl_translate (float x,
float y,
float z);
/**
* cogl_rotate:
* @angle: Angle in degrees to rotate.
* @x: X-component of vertex to rotate around.
* @y: Y-component of vertex to rotate around.
* @z: Z-component of vertex to rotate around.
*
* 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.
*/
void cogl_rotate (float angle,
float x,
float y,
float z);
/**
* cogl_get_modelview_matrix:
* @matrix: pointer to a CoglMatrix to recieve the matrix
*
* Stores the current model-view matrix in @matrix.
*/
void cogl_get_modelview_matrix (CoglMatrix *matrix);
/**
* cogl_get_projection_matrix:
* @matrix: pointer to a CoglMatrix to recieve the matrix
*
* Stores the current projection matrix in @matrix.
*/
void cogl_get_projection_matrix (CoglMatrix *matrix);
/**
* cogl_get_viewport:
* @v: pointer to a 4 element array of #float<!-- -->s to
* receive the viewport dimensions.
*
* 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.
*/
void cogl_get_viewport (float v[4]);
/**
* cogl_enable_depth_test:
* @setting: %TRUE to enable depth testing or %FALSE to disable.
*
* 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.
*/
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);
/**
* CoglFogMode:
* @COGL_FOG_MODE_LINEAR: Calculates the fog blend factor as:
* <programlisting>
* f = end - eye_distance / end - start
* </programlisting>
* @COGL_FOG_MODE_EXPONENTIAL: Calculates the fog blend factor as:
* <programlisting>
* f = e ^ -(density * eye_distance)
* </programlisting>
* @COGL_FOG_MODE_EXPONENTIAL_SQUARED: Calculates the fog blend factor as:
* <programlisting>
* f = e ^ -(density * eye_distance)^2
* </programlisting>
*
* 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:
* <programlisting>
* f = end - eye_distance / end - start
* </programlisting>
* Where eye_distance is the distance of the current fragment in eye
* coordinates from the origin.
*/
typedef enum _CoglFogMode
{
COGL_FOG_MODE_LINEAR,
COGL_FOG_MODE_EXPONENTIAL,
COGL_FOG_MODE_EXPONENTIAL_SQUARED,
} CoglFogMode;
/**
* cogl_set_fog:
* @fog_color: The color of the fog
* @mode: A CoglFogMode that determines the equation used to calculate the
* fogging blend factor.
* @density: Used by the EXPONENTIAL and EXPONENTIAL_SQUARED CoglFogMode
* equations.
* @z_near: Position along z-axis where no fogging should be applied
* @z_far: Position along z-axes where full fogging should be applied
*
* 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().
*/
void cogl_set_fog (const CoglColor *fog_color,
CoglFogMode mode,
float density,
float z_near,
float z_far);
/**
* cogl_disable_fog:
*
* This function disables fogging, so primitives drawn afterwards will not be
* blended with any previously set fog color.
*/
void cogl_disable_fog (void);
/**
* cogl_clear:
* @color: Background color to clear to
*
* Clears the color buffer to @color. The depth buffer and stencil
* buffers are also cleared.
*/
void cogl_clear (const CoglColor *color);
/**
* cogl_set_source:
* @material: A CoglMaterial object
*
* 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
*/
void cogl_set_source (CoglHandle material);
/**
* cogl_set_source_color:
* @color: a #CoglColor
*
* 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.
*
* Since: 1.0
*/
void cogl_set_source_color (const CoglColor *color);
/**
* cogl_set_source_color4ub:
* @red: value of the red channel, between 0 and 255
* @green: value of the green channel, between 0 and 255
* @blue: value of the blue channel, between 0 and 255
* @alpha: value of the alpha channel, between 0 and 255
*
* 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.
*
* Since: 1.0
*/
void cogl_set_source_color4ub (guint8 red,
guint8 green,
guint8 blue,
guint8 alpha);
/**
* cogl_set_source_color4f:
* @red: value of the red channel, between 0 and %1.0
* @green: value of the green channel, between 0 and %1.0
* @blue: value of the blue channel, between 0 and %1.0
* @alpha: value of the alpha channel, between 0 and %1.0
*
* 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.
*
* Since: 1.0
*/
void cogl_set_source_color4f (float red,
float green,
float blue,
float alpha);
/**
* cogl_set_source_texture:
* @texture_handle: The Cogl texture you want as your source
*
* 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:
* <programlisting>
* 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);
* </programlisting>
*
* Since 1.0
*/
void cogl_set_source_texture (CoglHandle texture_handle);
/**
* SECTION:cogl-clipping
* @short_description: Fuctions for manipulating a stack of clipping regions
*
* To support clipping your geometry to rectangles or paths Cogl exposes a
* stack based API whereby each clip region you push onto the stack is
* intersected with the previous region.
*/
/**
* cogl_clip_push:
* @x_offset: left edge of the clip rectangle
* @y_offset: top edge of the clip rectangle
* @width: width of the clip rectangle
* @height: height of the clip rectangle
*
* Specifies a rectangular clipping area for all subsequent drawing
* operations. Any drawing commands that extend outside the rectangle
* will be clipped so that only the portion inside the rectangle will
* be displayed. The rectangle dimensions are transformed by the
* current model-view matrix.
*
* The rectangle is intersected with the current clip region. To undo
* the effect of this function, call cogl_clip_pop().
*/
void cogl_clip_push (float x_offset,
float y_offset,
float width,
float height);
/**
* cogl_clip_push_from_path:
*
* Sets a new clipping area using the current path. The current path
* is then cleared. The clipping area is intersected with the previous
* clipping area. To restore the previous clipping area, call
* cogl_clip_pop().
*
* Since: 1.0
*/
void cogl_clip_push_from_path (void);
/**
* cogl_clip_push_from_path_preserve:
*
* Sets a new clipping area using the current path. The current path
* is then cleared. The clipping area is intersected with the previous
* clipping area. To restore the previous clipping area, call
* cogl_clip_pop().
*
* Since: 1.0
*/
void cogl_clip_push_from_path_preserve (void);
/**
* cogl_clip_pop:
*
* Reverts the clipping region to the state before the last call to
* cogl_clip_push().
*/
void cogl_clip_pop (void);
/**
* cogl_clip_ensure:
*
* Ensures that the current clipping region has been set in GL. This
* will automatically be called before any Cogl primitives but it
* maybe be neccessary to call if you are using raw GL calls with
* clipping.
*
* Since: 1.0
*/
void cogl_clip_ensure (void);
/**
* cogl_clip_stack_save:
*
* Save the entire state of the clipping stack and then clear all
* clipping. The previous state can be returned to with
* cogl_clip_stack_restore(). Each call to cogl_clip_push() after this
* must be matched by a call to cogl_clip_pop() before calling
* cogl_clip_stack_restore().
*
* Since: 0.8.2
*/
void cogl_clip_stack_save (void);
/**
* cogl_clip_stack_restore:
*
* Restore the state of the clipping stack that was previously saved
* by cogl_clip_stack_save().
*
* Since: 0.8.2
*/
void cogl_clip_stack_restore (void);
G_END_DECLS
#undef __COGL_H_INSIDE__
#endif /* __COGL_H__ */