mutter/cogl.h.in

/*
 * 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__

#define __COGL_H_INSIDE__

#include <glib.h>

#include <cogl/cogl-defines-@CLUTTER_COGL@.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-path.h>
#include <cogl/cogl-shader.h>
#include <cogl/cogl-texture.h>
#include <cogl/cogl-types.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);

/* 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
 *
 * Multiplies the current model-view matrix by one that scales the x
 * and y axes by the given values.
 */
void            cogl_scale                    (float        x,
                                               float        y);

/**
 * 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:
 * @m: pointer to a 4x4 array of #float<!-- -->s to receive the matrix
 *
 * Stores the current model-view matrix in @m. The matrix is in
 * column-major order.
 */
void            cogl_get_modelview_matrix     (float        m[16]);

/**
 * cogl_get_projection_matrix:
 * @m: pointer to a 4x4 array of #float<!-- -->s to receive the matrix
 *
 * Stores the current projection matrix in @m. The matrix is in
 * column-major order.
 */
void            cogl_get_projection_matrix    (float        m[16]);

/**
 * 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_clip_set:
 * @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_unset().
 */
void            cogl_clip_set                 (float        x_offset,
                                               float        y_offset,
                                               float        width,
                                               float        height);

/**
 * cogl_clip_set_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_unset().
 *
 * Since: 1.0
 */
void            cogl_clip_set_from_path       (void);

/**
 * cogl_clip_set_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_unset().
 *
 * Since: 1.0
 */
void            cogl_clip_set_from_path_preserve (void);

/**
 * cogl_clip_unset:
 *
 * Reverts the clipping region to the state before the last call to
 * cogl_clip_set().
 */
void            cogl_clip_unset               (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_set() after this
 * must be matched by a call to cogl_clip_unset() 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);

/**
 * 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);

/**
 * cogl_alpha_func:
 * @func: the comparison function to use, one of CGL_NEVER, CGL_LESS,
 * CGL_EQUAL, CGL_LEQUAL, CGL_GREATER, CGL_NOTEQUAL, CGL_GEQUAL and GL_ALWAYS.
 * @ref: reference value.
 *
 * Changes the alpha test to use the specified function specified in @func,
 * comparing with the value in @ref. The default function is CGL_ALWAYS the
 * initial reference value is 1.0.
 */
void            cogl_alpha_func               (COGLenum            func,
                                               float        ref);

/**
 * cogl_fog_set:
 * @fog_color: The color of the fog
 * @density: Ignored
 * @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
 * 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 the next call to
 * cogl_paint_init().
 */
void            cogl_fog_set                  (const CoglColor *fog_color,
                                               float        density,
                                               float        z_near,
                                               float        z_far);

/**
 * cogl_paint_init:
 * @color: Background color to clear to
 *
 * Clears the color buffer to @color. The depth buffer and stencil
 * buffers are also cleared and fogging and lighting are disabled.
 */
void            cogl_paint_init               (const CoglColor *color);

G_END_DECLS

#undef __COGL_H_INSIDE__

#endif /* __COGL_H__ */