mutter/clutter/cogl/cogl-path.h
Neil Roberts 89e7552ca3 Bug 1172 - Disjoint paths and clip to path
* clutter/cogl/cogl-path.h:
	* clutter/cogl/common/cogl-primitives.c:
	* clutter/cogl/common/cogl-primitives.h:
	* clutter/cogl/gl/cogl-primitives.c:
	* clutter/cogl/gles/cogl-primitives.c: Changed the semantics of
	cogl_path_move_to. Previously this always started a new path but
	now it instead starts a new disjoint sub path. The path isn't
	cleared until you call either cogl_path_stroke, cogl_path_fill or
	cogl_path_new. There are also cogl_path_stroke_preserve and
	cogl_path_fill_preserve functions.

	* clutter/cogl/gl/cogl-context.c:
	* clutter/cogl/gl/cogl-context.h:
	* clutter/cogl/gles/cogl-context.c:
	* clutter/cogl/gles/cogl-context.h: Convert the path nodes array
	to a GArray.

	* clutter/cogl/gl/cogl-texture.c:
	* clutter/cogl/gles/cogl-texture.c: Call cogl_clip_ensure

	* clutter/cogl/common/cogl-clip-stack.c:
	* clutter/cogl/common/cogl-clip-stack.h: Simplified the clip
	stack code quite a bit to make it more maintainable.  Previously
	whenever you added a new clip it would go through a separate route
	to immediately intersect with the current clip and when you
	removed it again it would immediately rebuild the entire clip. Now
	when you add or remove a clip it doesn't do anything immediately
	but just sets a dirty flag instead.

	* clutter/cogl/gl/cogl.c:
	* clutter/cogl/gles/cogl.c: Taken away the code to intersect
	stencil clips when there is exactly one stencil bit. It won't work
	with path clips and I don't know of any platform that doesn't have
	eight or zero stencil bits. It needs at least three bits to
	intersect a path with an existing clip. cogl_features_init now
	just decides you don't have a stencil buffer at all if you have
	less than three bits.

	* clutter/cogl/cogl.h.in: New functions and documentation.

	* tests/interactive/test-clip.c: Replaced with a different test
	that lets you add and remove clips. The three different mouse
	buttons add clips in different shapes. This makes it easier to
	test multiple levels of clipping.

	* tests/interactive/test-cogl-primitives.c: Use
	cogl_path_stroke_preserve when using the same path again.

	* doc/reference/cogl/cogl-sections.txt: Document the new
	functions.
2008-12-04 13:45:09 +00:00

359 lines
13 KiB
C

/* cogl-path.h: Path primitives
* This file is part of Clutter
*
* Copyright (C) 2008 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, see <http://www.gnu.org/licenses/>.
*/
#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: X coordinate of the top-left corner
* @y: Y coordinate of the top-left corner
* @width: Width of the rectangle
* @height: Height of the rectangle
*
* Fills a rectangle at the given coordinates with the current
* drawing color in a highly optimizied fashion.
**/
void cogl_rectangle (gint x,
gint y,
guint width,
guint height);
/**
* cogl_rectanglex:
* @x: X coordinate of the top-left corner
* @y: Y coordinate of the top-left corner
* @width: Width of the rectangle
* @height: Height of the rectangle
*
* A fixed-point version of cogl_fast_fill_rectangle.
**/
void cogl_rectanglex (CoglFixed x,
CoglFixed y,
CoglFixed width,
CoglFixed height);
/**
* 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 (CoglFixed x,
CoglFixed 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 (CoglFixed x,
CoglFixed 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 (CoglFixed x,
CoglFixed 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 (CoglFixed x,
CoglFixed 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 radious 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 (CoglFixed center_x,
CoglFixed center_y,
CoglFixed radius_x,
CoglFixed radius_y,
CoglAngle angle_1,
CoglAngle angle_2);
/**
* cogl_path_curve_to:
* @x1: X coordinate of the second bezier control point
* @y1: Y coordinate of the second bezier control point
* @x2: X coordinate of the third bezier control point
* @y2: Y coordinate of the third bezier control point
* @x3: X coordinate of the fourth bezier control point
* @y3: 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 (CoglFixed x1,
CoglFixed y1,
CoglFixed x2,
CoglFixed y2,
CoglFixed x3,
CoglFixed y3);
/**
* cogl_path_rel_curve_to:
* @x1: X coordinate of the second bezier control point
* @y1: Y coordinate of the second bezier control point
* @x2: X coordinate of the third bezier control point
* @y2: Y coordinate of the third bezier control point
* @x3: X coordinate of the fourth bezier control point
* @y3: 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 (CoglFixed x1,
CoglFixed y1,
CoglFixed x2,
CoglFixed y2,
CoglFixed x3,
CoglFixed y3);
/**
* 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:
* @x1: X coordinate of the start line vertex
* @y1: Y coordinate of the start line vertex
* @x2: X coordinate of the end line vertex
* @y2: 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 (CoglFixed x1,
CoglFixed y1,
CoglFixed x2,
CoglFixed y2);
/**
* cogl_path_polyline:
* @coords: 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 (CoglFixed *coords,
gint num_points);
/**
* cogl_path_polygon:
* @coords: 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 (CoglFixed *coords,
gint num_points);
/**
* cogl_path_rectangle:
* @x: X coordinate of the top-left corner.
* @y: Y coordinate of the top-left corner.
* @width: Rectangle width.
* @height: Rectangle height.
*
* 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 (CoglFixed x,
CoglFixed y,
CoglFixed width,
CoglFixed height);
/**
* 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 (CoglFixed center_x,
CoglFixed center_y,
CoglFixed radius_x,
CoglFixed radius_y);
/**
* cogl_path_round_rectangle:
* @x: X coordinate of the top-left corner
* @y: Y coordinate of the top-left corner
* @width: Width of the rectangle
* @height: Height of the rectangle
* @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 (CoglFixed x,
CoglFixed y,
CoglFixed width,
CoglFixed height,
CoglFixed radius,
CoglAngle arc_step);
G_END_DECLS
#endif /* __COGL_PATH_H__ */