gwin_graph.h

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/*
 * This file is subject to the terms of the GFX License. If a copy of
 * the license was not distributed with this file, you can obtain one at:
 *
 *              http://ugfx.org/license.html
 */

/**
 * @file  src/gwin/gwin_graph.h
 * @brief GWIN GRAPH module header file
 *
 * @defgroup Graph Graph
 * @ingroup Windows
 *
 * @brief Graph window. Used to display highly customizable graphs.
 *
 * @details GWIN allows it to easily draw graphs.
 *
 * @pre   GFX_USE_GWIN must be set to TRUE in your gfxconf.h
 * @pre   GWIN_NEED_GRAPH must be set to TRUE in your gfxconf.h
 *
 * @{
 */

#ifndef _GWIN_GRAPH_H
#define _GWIN_GRAPH_H

/* This file is included within "src/gwin/gwin.h" */

typedef enum GGraphPointType_e {
  GGRAPH_POINT_NONE, GGRAPH_POINT_DOT, GGRAPH_POINT_SQUARE, GGRAPH_POINT_CIRCLE
  } GGraphPointType;

typedef struct GGraphPointStyle_t {
  GGraphPointType   type;
  coord_t       size;
  color_t       color;
  } GGraphPointStyle;

typedef enum GGraphLineType_e {
  GGRAPH_LINE_NONE, GGRAPH_LINE_SOLID, GGRAPH_LINE_DOT, GGRAPH_LINE_DASH
  } GGraphLineType;

typedef struct GGraphLineStyle_t {
  GGraphLineType    type;
  coord_t       size;
  color_t       color;
  } GGraphLineStyle;

typedef struct GGraphGridStyle_t {
  GGraphLineType    type;
  coord_t       size;
  color_t       color;
  coord_t       spacing;
  } GGraphGridStyle;

typedef struct GGraphStyle_t {
  GGraphPointStyle  point;
  GGraphLineStyle   line;
  GGraphLineStyle   xaxis;
  GGraphLineStyle   yaxis;
  GGraphGridStyle   xgrid;
  GGraphGridStyle   ygrid;
  uint16_t      flags;
    #define GWIN_GRAPH_STYLE_XAXIS_POSITIVE_ARROWS  0x0001
    #define GWIN_GRAPH_STYLE_XAXIS_NEGATIVE_ARROWS  0x0002
    #define GWIN_GRAPH_STYLE_YAXIS_POSITIVE_ARROWS  0x0004
    #define GWIN_GRAPH_STYLE_YAXIS_NEGATIVE_ARROWS  0x0008
    #define GWIN_GRAPH_STYLE_POSITIVE_AXIS_ARROWS (GWIN_GRAPH_STYLE_XAXIS_POSITIVE_ARROWS|GWIN_GRAPH_STYLE_YAXIS_POSITIVE_ARROWS)
    #define GWIN_GRAPH_STYLE_NEGATIVE_AXIS_ARROWS (GWIN_GRAPH_STYLE_XAXIS_NEGATIVE_ARROWS|GWIN_GRAPH_STYLE_YAXIS_NEGATIVE_ARROWS)
    #define GWIN_GRAPH_STYLE_XAXIS_ARROWS     (GWIN_GRAPH_STYLE_XAXIS_POSITIVE_ARROWS|GWIN_GRAPH_STYLE_XAXIS_NEGATIVE_ARROWS)
    #define GWIN_GRAPH_STYLE_YAXIS_ARROWS     (GWIN_GRAPH_STYLE_YAXIS_POSITIVE_ARROWS|GWIN_GRAPH_STYLE_YAXIS_NEGATIVE_ARROWS)
    #define GWIN_GRAPH_STYLE_ALL_AXIS_ARROWS    (GWIN_GRAPH_STYLE_XAXIS_ARROWS|GWIN_GRAPH_STYLE_YAXIS_ARROWS)
} GGraphStyle;

// A graph window
typedef struct GGraphObject {
  GWindowObject   g;
  GGraphStyle     style;
  coord_t       xorigin, yorigin;
  coord_t       lastx, lasty;
  } GGraphObject;

/*===========================================================================*/
/* External declarations.                                                    */
/*===========================================================================*/

#ifdef __cplusplus
extern "C" {
#endif

/**
 * @brief   Create a graph window.
 * @return  NULL if there is no resultant drawing area, otherwise a window handle.
 *
 * @param[in] g     The GDisplay to display this window on
 * @param[in] gg    The GGraphObject structure to initialise. If this is NULL the structure is dynamically allocated.
 * @param[in] pInit   The initialization parameters to use
 *
 * @note        The drawing color and the background color get set to the current defaults. If you haven't called
 *            @p gwinSetDefaultColor() or @p gwinSetDefaultBgColor() then these are White and Black respectively.
 * @note        The font gets set to the current default font. If you haven't called @p gwinSetDefaultFont() then there
 *            is no default font and text drawing operations will no nothing.
 * @note        The dimensions and position may be changed to fit on the real screen.
 * @note        A graph does not save the drawing state. It is not automatically redrawn if the window is moved or
 *            its visibility state is changed.
 * @note        The coordinate system within the window for graphing operations (but not for any other drawing
 *            operation) is relative to the bottom left corner and then shifted right and up by the specified
 *            graphing x and y origin. Note that this system is inverted in the y direction relative to the display.
 *            This gives the best graphing arrangement ie. increasing y values are closer to the top of the display.
 *
 * @api
 */
GHandle gwinGGraphCreate(GDisplay *g, GGraphObject *gg, const GWindowInit *pInit);
#define gwinGraphCreate(gg, pInit)      gwinGGraphCreate(GDISP, gg, pInit)

/**
 * @brief   Set the style of the graphing operations.
 *
 * @param[in] gh    The window handle (must be a graph window)
 * @param[in] pstyle  The graph style to set.
 * @note        The graph is not automatically redrawn. The new style will apply to any new drawing operations.
 *
 * @api
 */
void gwinGraphSetStyle(GHandle gh, const GGraphStyle *pstyle);

/**
 * @brief   Set the origin for graphing operations.
 *
 * @param[in] gh    The window handle (must be a graph window)
 * @param[in] x, y    The new origin for the graph (in graph coordinates relative to the bottom left corner).
 * @note        The graph is not automatically redrawn. The new origin will apply to any new drawing operations.
 *
 * @api
 */
void gwinGraphSetOrigin(GHandle gh, coord_t x, coord_t y);

/**
 * @brief   Draw the axis and the background grid.
 *
 * @param[in] gh    The window handle (must be a graph window)
 * @note        The graph is not automatically cleared. You must do that first by calling gwinClear().
 *
 * @api
 */
void gwinGraphDrawAxis(GHandle gh);

/**
 * @brief   Start a new set of graphing data.
 * @details This prevents a line being drawn from the last data point to the next point to be drawn.
 *
 * @param[in] gh    The window handle (must be a graph window)
 *
 * @api
 */
void gwinGraphStartSet(GHandle gh);

/**
 * @brief   Draw a graph point.
 * @details A graph point and a line connecting to the previous point will be drawn.
 *
 * @param[in] gh    The window handle (must be a graph window)
 * @param[in] x, y    The new point for the graph.
 *
 * @api
 */
void gwinGraphDrawPoint(GHandle gh, coord_t x, coord_t y);

/**
 * @brief   Draw multiple graph points.
 * @details A graph point and a line connecting to each previous point will be drawn.
 *
 * @param[in] gh    The window handle (must be a graph window)
 * @param[in] points  The array of points for the graph.
 * @param[in] count   The number of points in the array.
 * @note        This is slightly more efficient than calling gwinGraphDrawPoint() repeatedly.
 *
 * @api
 */
void gwinGraphDrawPoints(GHandle gh, const point *points, unsigned count);

#ifdef __cplusplus
}
#endif

#endif  /* _GWIN_GRAPH_H */
/** @} */