mutter/clutter/cogl/cogl/cogl-path.h
Robert Bragg 43efab46bc Intial Re-layout of the Cogl source code and introduction of a Cogl Winsys
As part of an incremental process to have Cogl be a standalone project we
want to re-consider how we organise the Cogl source code.

Currently this is the structure I'm aiming for:
cogl/
    cogl/
	<put common source here>
	winsys/
	   cogl-glx.c
	   cogl-wgl.c
	driver/
	    gl/
	    gles/
	os/ ?
    utils/
	cogl-fixed
	cogl-matrix-stack?
        cogl-journal?
        cogl-primitives?
    pango/

The new winsys component is a starting point for migrating window system
code (i.e.  x11,glx,wgl,osx,egl etc) from Clutter to Cogl.

The utils/ and pango/ directories aren't added by this commit, but they are
noted because I plan to add them soon.

Overview of the planned structure:

* The winsys/ API is the API that binds OpenGL to a specific window system,
  be that X11 or win32 etc.  Example are glx, wgl and egl. Much of the logic
  under clutter/{glx,osx,win32 etc} should migrate here.

* Note there is also the idea of a winsys-base that may represent a window
  system for which there are multiple winsys APIs.  An example of this is
  x11, since glx and egl may both be used with x11.  (currently only Clutter
  has the idea of a winsys-base)

* The driver/ represents a specific varient of OpenGL. Currently we have "gl"
  representing OpenGL 1.4-2.1 (mostly fixed function) and "gles" representing
  GLES 1.1 (fixed funciton) and 2.0 (fully shader based)

* Everything under cogl/ should fundamentally be supporting access to the
  GPU.  Essentially Cogl's most basic requirement is to provide a nice GPU
  Graphics API and drawing a line between this and the utility functionality
  we add to support Clutter should help keep this lean and maintainable.

* Code under utils/ as suggested builds on cogl/ adding more convenient
  APIs or mechanism to optimize special cases. Broadly speaking you can
  compare cogl/ to OpenGL and utils/ to GLU.

* clutter/pango will be moved to clutter/cogl/pango

How some of the internal configure.ac/pkg-config terminology has changed:
backendextra -> CLUTTER_WINSYS_BASE # e.g. "x11"
backendextralib -> CLUTTER_WINSYS_BASE_LIB # e.g. "x11/libclutter-x11.la"
clutterbackend -> {CLUTTER,COGL}_WINSYS # e.g. "glx"
CLUTTER_FLAVOUR -> {CLUTTER,COGL}_WINSYS
clutterbackendlib -> CLUTTER_WINSYS_LIB
CLUTTER_COGL -> COGL_DRIVER # e.g. "gl"

Note: The CLUTTER_FLAVOUR and CLUTTER_COGL defines are kept for apps

As the first thing to take advantage of the new winsys component in Cogl;
cogl_get_proc_address() has been moved from cogl/{gl,gles}/cogl.c into
cogl/common/cogl.c and this common implementation first trys
_cogl_winsys_get_proc_address() but if that fails then it falls back to
gmodule.
2009-10-16 18:58:50 +01:00

348 lines
13 KiB
C

/*
* Cogl
*
* An object oriented GL/GLES Abstraction/Utility Layer
*
* Copyright (C) 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.
*/
#if !defined(__COGL_H_INSIDE__) && !defined(CLUTTER_COMPILATION)
#error "Only <cogl/cogl.h> can be included directly."
#endif
#ifndef __COGL_PATH_H__
#define __COGL_PATH_H__
#include <cogl/cogl-types.h>
G_BEGIN_DECLS
/**
* SECTION:cogl-primitives
* @short_description: Functions that draw various primitive shapes and
* allow for construction of more complex paths.
*
* There are three levels on which drawing with cogl can be used. The
* highest level functions construct various simple primitive shapes
* to be either filled or stroked. Using a lower-level set of functions
* more complex and arbitrary paths can be constructed by concatenating
* straight line, bezier curve and arc segments. Additionally there
* are utility functions that draw the most common primitives - rectangles
* and trapezoids - in a maximaly optimized fashion.
*
* When constructing arbitrary paths, the current pen location is
* initialized using the move_to command. The subsequent path segments
* implicitly use the last pen location as their first vertex and move
* the pen location to the last vertex they produce at the end. Also
* there are special versions of functions that allow specifying the
* vertices of the path segments relative to the last pen location
* rather then in the absolute coordinates.
*/
/**
* cogl_rectangle:
* @x_1: X coordinate of the top-left corner
* @y_1: Y coordinate of the top-left corner
* @x_2: X coordinate of the bottom-right corner
* @y_2: Y coordinate of the bottom-right corner
*
* Fills a rectangle at the given coordinates with the current source material
**/
void cogl_rectangle (float x_1,
float y_1,
float x_2,
float y_2);
/**
* cogl_path_fill:
*
* Fills the constructed shape using the current drawing color. The
* current path is then cleared. To use the path again, call
* cogl_path_fill_preserve() instead.
**/
void cogl_path_fill (void);
/**
* cogl_path_fill_preserve:
*
* Fills the constructed shape using the current drawing color and
* preserves the path to be used again.
*
* Since: 1.0
**/
void cogl_path_fill_preserve (void);
/**
* cogl_path_stroke:
*
* Strokes the constructed shape using the current drawing color and a
* width of 1 pixel (regardless of the current transformation
* matrix). To current path is then cleared. To use the path again,
* call cogl_path_stroke_preserve() instead.
**/
void cogl_path_stroke (void);
/**
* cogl_path_stroke_preserve:
*
* Strokes the constructed shape using the current drawing color and
* preserves the path to be used again.
*
* Since: 1.0
**/
void cogl_path_stroke_preserve (void);
/**
* cogl_path_new:
*
* Clears the current path and starts a new one.
*
* Since: 1.0
*/
void cogl_path_new (void);
/**
* cogl_path_move_to:
* @x: X coordinate of the pen location to move to.
* @y: Y coordinate of the pen location to move to.
*
* Moves the pen to the given location. If there is an existing path
* this will start a new disjoint subpath.
**/
void cogl_path_move_to (float x,
float y);
/**
* cogl_path_rel_move_to:
* @x: X offset from the current pen location to move the pen to.
* @y: Y offset from the current pen location to move the pen to.
*
* Moves the pen to the given offset relative to the current pen
* location. If there is an existing path this will start a new
* disjoint subpath.
**/
void cogl_path_rel_move_to (float x,
float y);
/**
* cogl_path_line_to:
* @x: X coordinate of the end line vertex
* @y: Y coordinate of the end line vertex
*
* Adds a straight line segment to the current path that ends at the
* given coordinates.
**/
void cogl_path_line_to (float x,
float y);
/**
* cogl_path_rel_line_to:
* @x: X offset from the current pen location of the end line vertex
* @y: Y offset from the current pen location of the end line vertex
*
* Adds a straight line segment to the current path that ends at the
* given coordinates relative to the current pen location.
**/
void cogl_path_rel_line_to (float x,
float y);
/**
* cogl_path_arc:
* @center_x: X coordinate of the elliptical arc center
* @center_y: Y coordinate of the elliptical arc center
* @radius_x: X radius of the elliptical arc
* @radius_y: Y radius of the elliptical arc
* @angle_1: Angle in the unit-circle at which the arc begin
* @angle_2: Angle in the unit-circle at which the arc ends
*
* Adds an elliptical arc segment to the current path. A straight line
* segment will link the current pen location with the first vertex
* of the arc. If you perform a move_to to the arcs start just before
* drawing it you create a free standing arc.
**/
void cogl_path_arc (float center_x,
float center_y,
float radius_x,
float radius_y,
float angle_1,
float angle_2);
/**
* cogl_path_curve_to:
* @x_1: X coordinate of the second bezier control point
* @y_1: Y coordinate of the second bezier control point
* @x_2: X coordinate of the third bezier control point
* @y_2: Y coordinate of the third bezier control point
* @x_3: X coordinate of the fourth bezier control point
* @y_3: Y coordinate of the fourth bezier control point
*
* Adds a cubic bezier curve segment to the current path with the given
* second, third and fourth control points and using current pen location
* as the first control point.
**/
void cogl_path_curve_to (float x_1,
float y_1,
float x_2,
float y_2,
float x_3,
float y_3);
/**
* cogl_path_rel_curve_to:
* @x_1: X coordinate of the second bezier control point
* @y_1: Y coordinate of the second bezier control point
* @x_2: X coordinate of the third bezier control point
* @y_2: Y coordinate of the third bezier control point
* @x_3: X coordinate of the fourth bezier control point
* @y_3: Y coordinate of the fourth bezier control point
*
* Adds a cubic bezier curve segment to the current path with the given
* second, third and fourth control points and using current pen location
* as the first control point. The given coordinates are relative to the
* current pen location.
*/
void cogl_path_rel_curve_to (float x_1,
float y_1,
float x_2,
float y_2,
float x_3,
float y_3);
/**
* cogl_path_close:
*
* Closes the path being constructed by adding a straight line segment
* to it that ends at the first vertex of the path.
**/
void cogl_path_close (void);
/**
* cogl_path_line:
* @x_1: X coordinate of the start line vertex
* @y_1: Y coordinate of the start line vertex
* @x_2: X coordinate of the end line vertex
* @y_2: Y coordinate of the end line vertex
*
* Constructs a straight line shape starting and ending at the given
* coordinates. If there is an existing path this will start a new
* disjoint sub-path.
**/
void cogl_path_line (float x_1,
float y_1,
float x_2,
float y_2);
/**
* cogl_path_polyline:
* @coords: (in) (array) (transfer none): A pointer to the first element of an
* array of fixed-point values that specify the vertex coordinates.
* @num_points: The total number of vertices.
*
* Constructs a series of straight line segments, starting from the
* first given vertex coordinate. If there is an existing path this
* will start a new disjoint sub-path. Each subsequent segment starts
* where the previous one ended and ends at the next given vertex
* coordinate.
*
* The coords array must contain 2 * num_points values. The first value
* represents the X coordinate of the first vertex, the second value
* represents the Y coordinate of the first vertex, continuing in the same
* fashion for the rest of the vertices. (num_points - 1) segments will
* be constructed.
**/
void cogl_path_polyline (float *coords,
gint num_points);
/**
* cogl_path_polygon:
* @coords: (in) (array) (transfer none): A pointer to the first element of
* an array of fixed-point values that specify the vertex coordinates.
* @num_points: The total number of vertices.
*
* Constructs a polygonal shape of the given number of vertices. If
* there is an existing path this will start a new disjoint sub-path.
*
* The coords array must contain 2 * num_points values. The first value
* represents the X coordinate of the first vertex, the second value
* represents the Y coordinate of the first vertex, continuing in the same
* fashion for the rest of the vertices.
**/
void cogl_path_polygon (float *coords,
gint num_points);
/**
* cogl_path_rectangle:
* @x_1: X coordinate of the top-left corner.
* @y_1: Y coordinate of the top-left corner.
* @x_2: X coordinate of the bottom-right corner.
* @y_2: Y coordinate of the bottom-right corner.
*
* Constructs a rectangular shape at the given coordinates. If there
* is an existing path this will start a new disjoint sub-path.
**/
void cogl_path_rectangle (float x_1,
float y_1,
float x_2,
float y_2);
/**
* cogl_path_ellipse:
* @center_x: X coordinate of the ellipse center
* @center_y: Y coordinate of the ellipse center
* @radius_x: X radius of the ellipse
* @radius_y: Y radius of the ellipse
*
* Constructs an ellipse shape. If there is an existing path this will
* start a new disjoint sub-path.
**/
void cogl_path_ellipse (float center_x,
float center_y,
float radius_x,
float radius_y);
/**
* cogl_path_round_rectangle:
* @x_1: X coordinate of the top-left corner.
* @y_1: Y coordinate of the top-left corner.
* @x_2: X coordinate of the bottom-right corner.
* @y_2: Y coordinate of the bottom-right corner.
* @radius: Radius of the corner arcs.
* @arc_step: Angle increment resolution for subdivision of
* the corner arcs.
*
* Constructs a rectangular shape with rounded corners. If there is an
* existing path this will start a new disjoint sub-path.
**/
void cogl_path_round_rectangle (float x_1,
float y_1,
float x_2,
float y_2,
float radius,
float arc_step);
G_END_DECLS
#endif /* __COGL_PATH_H__ */