drawingthings

package module
v1.3.0 Latest Latest
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 Go to latest Published: Dec 29, 2023 License: BSD-2-Clause-Views Imports: 12 Imported by: 1

README 

Drawing Things

Drawing things are either simple (line, text) or complex things (e.g. run or 
bar graphs)  which can be defined and then rendered using the sketch package. 
Sketch provides the common drawing API with underlying support for QT or 
Postscript output allowing the drawing things to paint themselves without 
explicit understanding of the differing interfaces.


Transition:
This repo, along with other related sketch and drawing repos are in transition.
With the recent announcement of the sale of github, I have decided to host 
my personal open source repos here.  Please have patience while these move.

Documentation

Index

Constants

View Source 
const (
	DT_BASE int = iota + 1 // start at 1 so if kind missing from json, the reduling 0 doesn't bugger us up
	DT_RECT
	DT_LINE
	DT_TEXT
	DT_ARC
	DT_POLY
	DT_CIRCLE
	DT_PIECHART
	DT_GRAPH
	DT_BARGRAPH
	DT_RUNGRAPH
	DT_TANGLE
	DT_REGPOLY
	DT_METER
	DT_CLOCK
	DT_IMAGE
	DT_BLIP
)
View Source 
const (
	DT_BGSTYLE_SOLID int = iota
	DT_BGSTYLE_TRANSP
	DT_BGSTYLE_OUTLINE
)
View Source 
const (
	DS_DEFAULT int = iota // immediately right
	DS_UP_RIGHT
	DS_UP_LEFT
	DS_LOW_LEFT
	DS_LOW_RIGHT
	DS_HIDDEN // no text; make first click for quick hide
	DS_MAX
)

data block location relative to triangle

View Source 
const (
	BLIP_KIND_T int = iota // what we draw; directional triangle
	BLIP_KIND_R            // non-directional rectangle
)
View Source 
const (
	XL_DEFAULT int = iota // x label styles
	XL_REVERSE
	XL_INDEX       // index in data rather than recorded sequence number
	XL_REV_INDEX   // reverse index order (data in normal order)
	XL_TIME        // hh:mm:ss
	XL_REV_TIME    // hhLmm:ss but max to min
	XL_TIME_HM     // only hh:mm
	XL_REV_TIME_HM // only hh:mm but max to min
	XL_TIME_H      // only hh
	XL_REV_TIME_H  // only hh but max to min
	XL_DATE
	XL_REV_DATE
	XL_DATE_TIME     // two tiered date and time  (hh:mm)
	XL_REV_DATE_TIME // two tiered date and time  (hh:mm)
)
View Source 
const (
	Meter_220 int = iota
	Meter_180
	Meter_90
)
View Source 
const (
	Needle_full int = iota // full needle line with box placed under the center point
	Needle_tic             // tic mark with box placed at center point
)
View Source 
const (
	Paint_smooth int = iota
	Paint_jump
)
View Source 
const (
	SOLID_LINE int = iota
	DASHED_LINE
	DOT_LINE
	DOT_DOT_DASH_LINE
	DOT_DASH_LINE
)

Variables

This section is empty.

Functions

func Circle_pt 

func Circle_pt(scale float64, cx float64, cy float64, radius float64, angle float64) *sktools.Point

Compute the point (x,y) on a circle assuming a center of cx,cy, angle formed by a straight line running from cx,cy to the point, and radius r. Scale is applied to the x,y and radius values

func Json_update 

func Json_update(dt Drawingthing_i, jblob interface{})

Json_update allows a set of updated values to be applied to an object using a json blob containing the fields that should be updated. Any field not contained in the blob should remain as it exists. The specific drawing type may not allow some fields (like the id) to be updated after creation, thus supplying them will have no effect.

func Line_style_to_pattern 

func Line_style_to_pattern(style int) []int

Line_style_to_pattern accepts a DT_*_LINE constant and returns an integer pattern that can be used by the underlying graphics construct to set the line drawing style.

func Rotate_pts 

func Rotate_pts(rpt *sktools.Point, points []*sktools.Point, angle float64) (new_points []*sktools.Point)

Types

type Drawingthing_i 

type Drawingthing_i interface {
	Contains(x float64, y float64) bool
	Get_data() *data_mgr.Data_group
	Get_id() string
	Get_text() string
	Is_kind(kind int) bool
	//Is_updated() || Needs_paint() || Is_animated()
	Nuke(sketch.Graphics_api)
	Paint(gc sketch.Graphics_api, scale float64)
	Preserve()
	Restore()
	Rotate(vertex float64, angle float64)
	Set_colour(cname string)
	Set_data(data interface{})
	Set_delta_hw(dheight float64, dwidth float64)
	Set_delta_length(dlength float64)
	Set_endpt(x1 float64, y1 float64)
	Set_fill(state bool)
	Set_fill_colour(cname string)
	Set_hw(height float64, width float64)
	Set_length(length float64)
	Set_line_style(style int)
	Set_iscale(new_scale float64)
	Set_scale(new_scale float64)
	Set_origin(new_xo float64, new_yo float64)
	Set_rel_origin(delta_xo float64, delta_yo float64)
	Set_vis_threshold(new_threshold float64)
	String() string
	Tickle(data interface{})
	To_json() (string, error)
}

The drawing thing interface. All drawingthings must implement these functions.

func Json2ScaledDt added in v1.2.5 

func Json2ScaledDt(jif interface{}, scale float64) (Drawingthing_i, error)

Given a json description of a drawing thing this function unpacks the json to determine the type, then creates the proper struct from the json. Finally it returns a pointer to the interface which then can be used as follows: 

dt, err = Json2ScaledDt( json_string, scale )
if err == nil {
	dt.Set_endpt( x, y )
}

The type of drawing thing is determined by the Kind field in the json which must be one of the DT_* constants. The struct is initialised with a call to the MK_default_*() function, and then the json is 'applied' over top; thus the json needs to supply only the values which override the defaults. For simple things, defaults are likely just all 0s, where as things like graphs the defaults are probalby much more complicated.

func Json2dt 

func Json2dt(jif interface{}) (Drawingthing_i, error)

Old proto to keep this change from being a breaking change. Deprecated; use Json2ScaledDt( jif, scale )

type Dt_bar_graph 

type Dt_bar_graph struct {
	Dt_graph_base
	// contains filtered or unexported fields
}

func Mk_default_bar_graph 

func Mk_default_bar_graph() *Dt_bar_graph

This generates a bar graph struct with defaults.

func (*Dt_bar_graph) Paint 

func (dt *Dt_bar_graph) Paint(gc sketch.Graphics_api, scale float64)

Paint will render the bar graph using the graphics context (gc) passed in.

func (*Dt_bar_graph) To_json 

func (dt *Dt_bar_graph) To_json() (string, error)

Return json from the underlying drawing thing.

type Dt_base 

type Dt_base struct {
	Id            string  // creator assigned id
	Kind          int     // one of the DT_* consts that identifies the type
	Colour        string  // colur name or rgb string
	Xo            float64 // 'origin' point; upper left x,y or center x,y depending on thing
	Yo            float64
	Scale         float64 // Different things need scale info for different reasons; it's kept here
	Rot_angle     float64 // rotation, degrees anti-clock with "3:00" being 0
	Rot_vertex    float64 // the vertex around which rotation happens
	Visible       bool
	Vis_threshold float64 // scale value below which the thing isn't painted
	// contains filtered or unexported fields
}

Field names must be public as we need to support json (un)packing.

func Mk_drawingthing 

func Mk_drawingthing(id string, kind dt_kind, xo float64, yo float64) (dt *Dt_base)

Generic (dt) make funciton

func (*Dt_base) Contains 

func (dt *Dt_base) Contains(x float64, y float64) bool

Contains returns true if the x,y coord passed in is within the bounding box of the thing. As a generic function, likely not suitable for many things, true is returned if the point is +/- 5 px in each direction. We expect that most things will override this.

func (*Dt_base) Get_data 

func (dt *Dt_base) Get_data() *data_mgr.Data_group

Get_data returns the data group associated with the drawing thing or nil if the drawing thing does not support/use data.

func (*Dt_base) Get_id 

func (dt *Dt_base) Get_id() string

Get_id returns the drawingthing's ID.

func (*Dt_base) Get_text 

func (dt *Dt_base) Get_text() string

Get_text returns the text string associated with the drawing thing or "" if the drawing thing does not support/use data. This is a specialised form of Get_data() which relieves the caller from getting an interface and needing to sort out the type.

func (*Dt_base) Is_kind 

func (dt *Dt_base) Is_kind(kind int) bool

Is_kind returns true if the kind passed in (DT_* const) is the same kind as the struct.

func (*Dt_base) Is_visible 

func (dt *Dt_base) Is_visible(scale float64) bool

Is_visible returns true if the thing's visible setting is true and the current value of scale is >= the vis_threshold value.

func (*Dt_base) Nuke 

func (dt *Dt_base) Nuke(sketch.Graphics_api)

Nuke will do any cleanup that is necessary.

func (*Dt_base) Paint 

func (dt *Dt_base) Paint(gc sketch.Graphics_api, scale float64)

Paint causes the drawingthing to be rendered using the sketch graphics context which is passed in. Scale is used by drawing things only to determine visibility based on current display scale, and does NOT affect the rendering of the thing.

func (*Dt_base) Preserve 

func (dt *Dt_base) Preserve()

Preserve allows the drawingthing to stash away information that it wants to ensure does not change during an update. By default we save/restore just the ID and kind. Each object may decide to do more and implement their own version of this function.

func (*Dt_base) Restore 

func (dt *Dt_base) Restore()

Restore allows the drawing thing to restore anything preserved, and/or to force additional computations on the next paint assuming that something affecting the paint (size, location, etc.) has changed. As a default, the ID will be restored and the updated boolean will be marked true.

func (*Dt_base) Rotate 

func (dt *Dt_base) Rotate(vertex float64, angle float64)

Rotate captures the information needed to rotate the thing when painted. The rotation point is given as a vertex number (1, 2, 3 etc.); rotation is then computed using the coordinates of the vertex. For some drawingthings, the vertex 0 indicates the center, and for some the vertex is ignored as the thing has a single definition of rotation.

func (*Dt_base) Set_colour 

func (dt *Dt_base) Set_colour(cname string)

Set_colur allows the drawingthing colur to be changed. For most drawingthings this is the outline or stroke colour, and for some drawing things (e.g. graphs) setting the colour likely has no effect. Cname (colouor name) can be a recognised name (e.g. green, red, or orange) or a hex rgb value in the form of either #rrggbb or 0xrrggbb.

func (*Dt_base) Set_data 

func (dt *Dt_base) Set_data(data_thing interface{})

Set_data allows a new piece of data to be added to the drawing thing. Data is different for each drawing thing. For a graph data will be a data group or possibly a data set, but for a text thing, the data will likely be a string.

This is a dummy function for things that don't support/use data.

func (*Dt_base) Set_delta_hw 

func (dt *Dt_base) Set_delta_hw(dheight float64, dwidth float64)

Set_delta_hw allows the height and width of a datathing to be changed by relative value. If the drawing thing supporst the concept of height and width, each are adjusted by adding the delta values passed to this funciton to the current height and width of the thing.

func (*Dt_base) Set_delta_length 

func (dt *Dt_base) Set_delta_length(length float64)

Set_delta_length allows the length of a drawing thing to be changed by a relative value. If the drawingthing supports the concept of length, it is adjusted by adding the value passed to this function.

func (*Dt_base) Set_endpt 

func (dt *Dt_base) Set_endpt(x1 float64, y1 float64)

Set_endpt allows an x,y coordinate to be passed to the drawingthing to set/adjust the thing's concept of an endpoint. For a line, this is the second point and for multi-pointed things this probably has no effect.

func (*Dt_base) Set_fill 

func (dt *Dt_base) Set_fill(state bool)

Set_fill allows the fill property (boolean) to be turned on or off. Passing true, sets the property and if the drawingthing has a concept of being filled, it will be filled when painted.

func (*Dt_base) Set_fill_colour 

func (dt *Dt_base) Set_fill_colour(cname string)

Set_fill_colour allows the fill colour to be adjusted. If the fill property is enabled (true) and the drawingthing supports the concept of being filled, the colour given will be used.

func (*Dt_base) Set_hw 

func (dt *Dt_base) Set_hw(height float64, width float64)

Set_hw allows the absolute height and width of the drawing thing to be set provided the drawing thing supports the concept of height and width.

func (*Dt_base) Set_iscale 

func (dt *Dt_base) Set_iscale(increment float64)

Set_iscale sets the painting scale for the drawingthing. The value passed is added to the current setting rather than used as an absolute. Some things, like graphs, might need to reset themselves if the scale is changed. See note about scale in drawingthing.go.

func (*Dt_base) Set_length 

func (dt *Dt_base) Set_length(length float64)

Set_hw allows the absolute length of the drawing thing to be set provided the drawing thing supports the concept of length.

func (*Dt_base) Set_line_style 

func (dt *Dt_base) Set_line_style(style int)

Set_line_style allows the line style (e.g. solid, dashed) to be set for those drawingthings which support it.

func (*Dt_base) Set_origin 

func (dt *Dt_base) Set_origin(new_xo float64, new_yo float64)

Set_origin allows the origin point to be changed effectively moving the object in the drawing plane. The internal updated flag is set as for some drawing things the change to the origin may cause a recomputation of other vertices.

func (*Dt_base) Set_rel_origin 

func (dt *Dt_base) Set_rel_origin(delta_xo float64, delta_yo float64)

Set_rel_origin changes the origin for the DT by adding the delta values to the current origin values.

func (*Dt_base) Set_scale 

func (dt *Dt_base) Set_scale(new_scale float64)

Set_scale sets the painting scale for the drawingthing. Some things, like graphs, might need to reset themselves if the scale is changed. See note about scale in drawingthing.go.

func (*Dt_base) Set_updated 

func (dt *Dt_base) Set_updated(state bool)

Set_updated toggles the internal updated flag.

func (*Dt_base) Set_vis_threshold 

func (dt *Dt_base) Set_vis_threshold(new_t float64)

Set_vis_threshold sets the scale threshold below which a drawing thing will not be painted. If the threshold is set to 2.0, then when the current scale is < 2.0 the effect will be to hide the thing.

func (*Dt_base) Set_visibility 

func (dt *Dt_base) Set_visibility(state bool)

Set_visibility allows the visible flag to be toggled. If the thing isn't visible it shouldn't paint.

func (*Dt_base) String 

func (dt *Dt_base) String() string

String implements the stringer interface allowing the object to be passed to fmt.*() functions etc. We get lazy and just bang the struct into json.

func (*Dt_base) Tickle 

func (dt *Dt_base) Tickle(data interface{})

A tickle from the outside world. data contains needed information in a format that is unique to the underlying thing.

func (*Dt_base) To_json 

func (dt *Dt_base) To_json() (string, error)

To_json converts the underlying drawing thing into a json blob in a string, and retruns it

func (*Dt_base) Updated added in v1.1.0 

func (dt *Dt_base) Updated() bool

type Dt_blip 

type Dt_blip struct {
	Dt_base // common fields and functions

	Tangle   *Dt_tangle
	Rect     *Dt_rect
	Raw_txt  string  // raw text for to_* functions
	Tcolour  string  // triangle outline colour
	Tfill    string  // triangel fill colour
	Txt_size float64 // size of the text to paint
	Heading  float64 // the rotation (degrees from 'north')
	Alt      float64 // alt in meters
	Crumbs   bool    // true if we are leaving droppings
	// contains filtered or unexported fields
}

func Mk_blip 

func Mk_blip(xo float64, yo float64, colour string, text string) *Dt_blip

Mk_blip creates a blip given the coordinates and text string. Text is assumed to be a single string with pipe (|) separated fields.

func Mk_def_blip 

func Mk_def_blip() (dt *Dt_blip)

Mk_def_blip creates a default blip struct.

func (*Dt_blip) Contains added in v1.2.0 

func (dt *Dt_blip) Contains(x float64, y float64) bool

Contains returns true if the point passed is in the triangle or in the bounding box of the text.

func (*Dt_blip) Paint 

func (dt *Dt_blip) Paint(gc sketch.Graphics_api, scale float64)

Paint draws the blip (triangle and text). If we were updated, we must first update the drawing things that we manage before we can paint them.

If crumbs are on, then we will paint the breadcrumb trail (droppings) starting with didx and wrapping to didx-1.

func (*Dt_blip) Preserve 

func (dt *Dt_blip) Preserve()

We override preserve and restore to capture the orign values before an update. If they change, then we update the droppings on restore.

func (*Dt_blip) Restore 

func (dt *Dt_blip) Restore()

If the origin changed, update the droppings. We also need to ensure that id and kind don't change.

func (*Dt_blip) Tickle 

func (dt *Dt_blip) Tickle(qualifier interface{})

We accept tickles which are assumed to be mouse interactions in the form of a sketch/tool interaction.

func (*Dt_blip) To_json 

func (dt *Dt_blip) To_json() (string, error)

To_json will generate a json string from this struct. Only public fields make it into the json.

type Dt_circle 

type Dt_circle struct {
	Dt_base // common fields and functions

	Fill_style int
	Fcolour    string // fill colour

	Radius     float64
	Line_style int
}

func Mk_circle 

func Mk_circle(xo float64, yo float64, radius float64, outline_colour string, fill bool, fill_colour string) *Dt_circle

Allow for easy programatic creation of a circle.

func Mk_def_circle 

func Mk_def_circle() (dt *Dt_circle)

Mk_def_circle creates a default circle struct.

func (*Dt_circle) Paint 

func (dt *Dt_circle) Paint(gc sketch.Graphics_api, scale float64)

Draw the circle with it's current folour outline, and fill style. If the visible attribute for the object is false, then it is not rendered.

func (*Dt_circle) Set_delta_length 

func (dt *Dt_circle) Set_delta_length(dr float64)

Adjust the current legngth (radius) by the delta value dr

func (*Dt_circle) Set_fill 

func (dt *Dt_circle) Set_fill(state bool)

Set the fill value. If true passed, then circle will be filled.

func (*Dt_circle) Set_fill_colour 

func (dt *Dt_circle) Set_fill_colour(cname string)

Set the fill colour to use when the circle fill state is true.

func (*Dt_circle) Set_length 

func (dt *Dt_circle) Set_length(r float64)

Set the length (radius) to the given value r

func (*Dt_circle) Set_line_style 

func (dt *Dt_circle) Set_line_style(style int)

Set_line_style allows the style of the outline to be changed after the thing has been created. Expects one of the *_LINE constants.

func (*Dt_circle) String 

func (dt *Dt_circle) String() string

func (*Dt_circle) To_json 

func (dt *Dt_circle) To_json() (string, error)

To_json will generate a json string from this struct.

type Dt_clock 

type Dt_clock struct {
	Dt_base // common fields and functions

	Font   string // Sans, Serif, are also legit
	Size   int
	Weight int    // stroke weight (bold-ness)
	Format string // GO style time format for output
	Zulu   bool
	Tz     string
	// contains filtered or unexported fields
}

func Mk_clock 

func Mk_clock(xo float64, yo float64, size float64, font string, colour string, tfmt string) *Dt_clock

Mk_clock allows an instance of the clock struct to be created directly rather than creating a generic drawing thing.

func Mk_default_clock 

func Mk_default_clock() *Dt_clock

Mk_default_clock makes a simple clock structure onto which a json string can be 'overlaid'.

func (*Dt_clock) Paint 

func (dt *Dt_clock) Paint(gc sketch.Graphics_api, scale float64)

Paint draws the clock according to the information in the struct.

func (*Dt_clock) Set_delta_hw 

func (dt *Dt_clock) Set_delta_hw(dsize float64, dwidth float64)

h and w are delta values which are added to the current size. Currently delth width is ignored.

func (*Dt_clock) Set_size 

func (dt *Dt_clock) Set_size(size float64, width float64)

Change the current size. Width is ignored at the moment.

func (*Dt_clock) String 

func (dt *Dt_clock) String() string

func (*Dt_clock) To_json 

func (dt *Dt_clock) To_json() (string, error)

To_json will generate a json string from this struct.

type Dt_graph_base 

type Dt_graph_base struct {
	Dt_base // common fields and functions

	Height        float64 // overall height,width of the 'sub page'	(before scaling)
	Width         float64
	ScaledH       float64 // height/width after scaling
	ScaledW       float64
	Gheight       float64 // height width of the plot area
	Gwidth        float64
	Orig_x        float64 // the offset of the origin on the sub page
	Orig_y        float64
	X_disp        float64 // displacment (up) from the origin that the xaxis should be written
	Ymargin       int     // y labels on left are written starting this distance to the left of the y axis
	Yrmargin      int     // right y title spaced over this many points from the right y axis
	Y_split       int     // number of sections we split in y direction
	X_split       int     // number of splits in x dir
	Label_size    int     // size of x/y label text
	Subtitle_size int     // size of axis title text
	Title_size    int     // size of main title

	// titles are written 5 pts to the inside of the respective subpage edge
	Title         string // main graph title
	X_title       string // title under x labels
	Y_ltitle      string // title on left
	Y_rtitle      string // title on right
	Title_font    string
	Subtitle_font string

	Data *data_mgr.Data_group

	Grid_colour     string // colour for the grid
	Axis_colour     string // colour for the axis
	Bg_colour       string // colour for the plot area background
	Sp_colour       string // colour for the sub page (background to the whole graph area)
	Title_colour    string // main title colour
	Subtitle_colour string // colur of x/y axis titles
	Label_colour    string // x and y axis labels
	X_lab_style     int    // style x labels to be written in

	Scale_fmt        string // format string (e.g. %.0f) used on axis labels
	Show_xgrid       bool
	Show_ygrid       bool
	Show_left_scale  bool // show the scale on the left axis
	Show_right_scale bool // show the scale on the right axis
	Show_xlabels     bool // show labels along x axis
	Show_left_yaxis  bool // allow painting of either y axis
	Show_right_yaxis bool

	Right_min  float64 // x-axis value for right y axis
	Right_max  float64 // top value for right y axis
	Left_min   float64 // x-axis value for left y axis
	Left_max   float64 // top value for left y axis
	Left_round float64 // top value to round to (e.g. 100 or 1000)

	Sp_created bool // indicates whether or not the subpage has been created
	IsScaled   bool // true if scaled height/width should be used
	// contains filtered or unexported fields
}

Form base class xo,yo define the lower left of the working area. The coordinates of the origin of the graph are offset from this. Height and Width are the overall 'clip area,' with gheight and gwidth used for the graph itself.

It might seem silly to define both the origin offset from the lower left of the graph xo,yo and a Y margin, but the ymargin is used to place the y labels such that they are not placed up against the left edge of the drawing area. Y-margin is the distance to the left of the y axis, not to the right of the drawing area left edge.

func Mk_base_graph 

func Mk_base_graph(xo float64, yo float64, height float64, width float64, gh float64, gw float64) *Dt_graph_base

------ public functions ------------------------------------------ 

Create a base graph with defaults.
This graph probalby has no value other than a place holder as it has no
real paint function associated with it.

func (*Dt_graph_base) Nuke 

func (dtg *Dt_graph_base) Nuke(gc sketch.Graphics_api)

Nuke will clean up the subpage associated with the drawing thing; if it exists. State is saved such that the active page remains the same. The drawing thing is assumed to be on the curently selected page, or on the root page.

func (*Dt_graph_base) Paint 

func (dt *Dt_graph_base) Paint(gc sketch.Graphics_api, scale float64)

Paint will paint the base graph. Probably useless as there is no data style associated with the base graph and thus nothing is plotted.

func (*Dt_graph_base) Preserve 

func (dt *Dt_graph_base) Preserve()

Preserve allows the drawingthing to stash away information that it wants to ensure does not change during an update. By default we save/restore just the ID and kind. Each object may decide to do more and implement their own version of this function.

func (*Dt_graph_base) Restore 

func (dt *Dt_graph_base) Restore()

Restore allows the drawing thing to restore anything preserved, and/or to force additional computations on the next paint assuming that something affecting the paint (size, location, etc.) has changed. As a default, the ID will be restored and the updated boolean will be marked true.

func (*Dt_graph_base) Set_data 

func (dt *Dt_graph_base) Set_data(data_thing interface{})

Set data does one of two things depending on what is passed in:

If the data_thing is a data_manger group or set, it attaches a data set to the graph. The data set is used when the paint function is called, but otherwise is assumed to be managed outside of the drawing thing environment.

When the data_thing is a string, it is assumed to conain information to apply to the already attached data group. The string is assumed to have information of the form: 

<set>:<seq>,<value> [<set>:<seq,<value>]  ...

The sequence value allows for both x,y plotting as well as either sequence series run/bar graphis or time oriented where seq is a unix timestamp. In any case it is treated as a float64.

func (*Dt_graph_base) Set_scale added in v1.2.4 

func (dt *Dt_graph_base) Set_scale(scale float64)

Set the desired scale. This applies only to the overall height/width used to manage the subpage. All other aspects of scaling the actual paint process are handled in the GC.

type Dt_image 

type Dt_image struct {
	Dt_base // common fields and functions

	Height float64 // bounding box that image will be scaled to fit in
	Width  float64
	Fname  string // where the image lives (.jpg/.png supported)
	Rfreq  int64  // seconds between reloads
	Border bool   // causes a border to be drawn round the image
	// contains filtered or unexported fields
}

Right now images are expected to be on disk, but that could change. The filename can be a single file name, or a list of file names which are separated by semicolons. These filenames can be cycled through with a call to the Load_next() or Load_prev() functions. Each filename can be a sublist of names, separated by commas. These sublists are treated as a single, stacked, image; the images are combined (with the first in the list being the "base") before painting.

Public names are captured when the struct is converted to json.

func Mk_default_image 

func Mk_default_image() *Dt_image

Mk_default_image creates a default image.

func Mk_image 

func Mk_image(gc sketch.Graphics_api, x0 float64, y0 float64,
	fname string, height float64, width float64,
	colour string, reload int64, border bool) *Dt_image

Mk_dt_image creates an image which will be positioned at the given point and scaled to fit proportionally in the bounding box described by height and width. If border is true, a rectangle outline will be painted round the image using the given colour. The image will be reloaded every 'reload' seconds.

The image file name may be a single filename, or a SEMICOLON separater list of filenames. Each filename in the list, or the single file name, may itself be a (sub)list of images. If the filename is a sublist, then it is assumed that these images are to be 'stacked' from first to last with the first being the 'base' image and each successive image layered or stacked on top. Black pickes in the stacked images are not written, thus those areas become 'transparant."

If a list of filenames is given, the first filename is slected and loaded. The user application may invoke the Load_next() or Load_prev() functions to cause a different file to be used.

func (*Dt_image) First_image 

func (dt *Dt_image) First_image()

First_image selects the first file in the list, when multiple given, and causes it to be reloaded.

func (*Dt_image) Fix_fnames 

func (dt *Dt_image) Fix_fnames()

Fix_fnames will take an object created with json that might have semicolon separated filenames in fname, and split them up as is needed to load.

func (*Dt_image) Last_image 

func (dt *Dt_image) Last_image()

Last_image selects the last file in the list, when multiple given, and causes it to be reloaded.

func (*Dt_image) Load_next 

func (dt *Dt_image) Load_next()

Load_next selects the next file in the list, when multiple given, and causes it to be reloaded.

func (*Dt_image) Load_prev 

func (dt *Dt_image) Load_prev()

Load_prev selects the previous file from the list, when multiple given, and causes it to be reloaded.

func (*Dt_image) Paint 

func (dt *Dt_image) Paint(gc sketch.Graphics_api, scale float64)

Paint will display the image. If the time to reload has passed, then a goroutine will be scheduled to reload the image which will be painted the first time this function is called after the load has completed.

func (*Dt_image) Reload 

func (dt *Dt_image) Reload(gc sketch.Graphics_api)

Reload is a function that can be run as a goroutine which will casue the image to be reloaded asynch. The image is loaded into the new-image component of the struct. When it is loaded, and ok, the swap flag is toggled allowing paint to move and use it.

Image is the only drawing thing that needs/uses scale to actually scale something rather than just to control visibility. This is because the image is scaled as it is loaded, not as it is painted, thus it cannot be adjusted at time of render.

func (*Dt_image) Set_data 

func (dt *Dt_image) Set_data(data_thing interface{})

Set_data allows a new filename to be supplied (optional) and causes an immediate reload of the image from the file. Data is a string or pointer to string of the form: 

[colour=<colour-value>,]{filename | -}

If colour is supplied, then the outline colour is set to true and the colour is set to the supplied value. If filename is supplied, then the filename is replaced with the one given. Filename may be a dash (-) to indicate no change to the source of the image.

Regardless of colour or filename change we schedule an update of the image unless one is already in progress.

func (*Dt_image) Set_endpt 

func (dt *Dt_image) Set_endpt(x float64, y float64)

Set_endpt is used to set the anchorpoint x,y for the image.

func (*Dt_image) Set_iscale 

func (dt *Dt_image) Set_iscale(increment float64)

Set_scale sets the painting scale for the image by adding the passed value to the current setting. We look to see if the new scale is different than the old scale and if it is we force a reload.

func (*Dt_image) Set_scale 

func (dt *Dt_image) Set_scale(new_scale float64)

Set_scale sets the painting scale for the image. We look to see if the new scale is different than the old scale and if it is we force a reload.

func (*Dt_image) String 

func (dt *Dt_image) String() string

String returns a string representation of the object: json in this case.

func (*Dt_image) Tickle 

func (dt *Dt_image) Tickle(idata interface{})

Deal with a tickle. Right now we support single token data strings: 

first/last -- rewind/fast forward list to beginning/end
next -- select next image in the list
prev -- select prev image in the list
reload - Force a reload

func (*Dt_image) To_json 

func (dt *Dt_image) To_json() (string, error)

To_json will generate a json string from this struct.

type Dt_line 

type Dt_line struct {
	Dt_base // common fields and functions

	X1 float64
	Y1 float64

	Line_style int
}

func Mk_line 

func Mk_line(x0 float64, y0 float64, x1 float64, y1 float64, colour string, style int) *Dt_line

Mk_dt_line creates a line with the given end points and returns a pointer to the structure.

func (*Dt_line) Paint 

func (dt *Dt_line) Paint(gc sketch.Graphics_api, scale float64)

Given a graphics context, do what is needed to draw the line.

func (*Dt_line) Set_endpt 

func (dt *Dt_line) Set_endpt(x1 float64, y1 float64)

func (*Dt_line) String 

func (dt *Dt_line) String() string

func (*Dt_line) To_json 

func (dt *Dt_line) To_json() (string, error)

To_json will generate a json string from this struct.

type Dt_meter 

type Dt_meter struct {
	Dt_base // common fields and functions

	Paint_style   int     // PS_ constants (smooth/jump)
	Radius        float64 // amuont the peak is shifted in the y direction from yo
	Needle_style  int
	Needle_colour string
	Text_colour   string
	Text_size     int // text size; if 0 we use preset values
	Arc_colour    string
	Arc_type      int // Meter_* constants
	Tic_marks     bool
	Value_box     bool    // if false, no digital value is displayed
	Center_box    bool    // for 220/90 center if true and in needle tic. if false placed below
	Smooth_factor float64 // number of calls required to move 10%
	Smooth_step   float64 // computed smoothing step for the current movement

	Val_cur    float64 // current value (min <= v <= max)
	Val_target float64 // target value (if smooth scrolling to transition current to target)
	Val_min    float64 // value range
	Val_max    float64
	// contains filtered or unexported fields
}

func Mk_default_meter 

func Mk_default_meter() (dt *Dt_meter)

Mk_def_meter creates a default meter struct.

func (*Dt_meter) Paint 

func (dt *Dt_meter) Paint(gc sketch.Graphics_api, scale float64)

Paint draws the meter according to the information in the struct.

func (*Dt_meter) Preserve 

func (dt *Dt_meter) Preserve()

Preerve saves the fields which may not be updated/overlaid. The generic Json_update() function in drawingthings.go will invoke this before overlaying the struct with caller json, and then will invoke retore() to restore the preserved values. This funciton is needed as the current value must be preserved when smooth adjusting the meter.

func (*Dt_meter) Restore 

func (dt *Dt_meter) Restore()

Restore copies presrved values back into the main struct. This allows us to protect some fields from being overlaid with user data. Id, Kind and Val_cur fields are preserved/restored.

func (*Dt_meter) Set_data 

func (dt *Dt_meter) Set_data(data_thing interface{})

Set_data sets the target value for the meter. If jump positioning is selected for the meter, then the needle will be shown in this position on the next paint. If smooth needle positioning is selected, then the needle will be moved in steps between the current position to the supplied target position. Target will be constrained between the current meter max and min values.

func (*Dt_meter) Tickle 

func (dt *Dt_meter) Tickle(idata interface{})

func (*Dt_meter) To_json 

func (dt *Dt_meter) To_json() (string, error)

To_json will generate a json string from this struct.

type Dt_piechart 

type Dt_piechart struct {
	Dt_base // common fields and functions

	Sep_colour string // the colour to use to separate pieces of the pie
	Fill_style int
	Fcolours   []string  // fill colours, one per slice
	Pcts       []float64 // percentages, one per slice

	Radius float64
}

func Mk_piechart 

func Mk_piechart(xo float64, yo float64, radius float64, outline_colour string, sep_colour string, pcts []float64, fillcolours []string) *Dt_piechart

Programatic creation of a pie chart. The colours an percentages can be a single element array, and added to over the lifespan of the object.

func Mk_piechart_values 

func Mk_piechart_values(xo float64, yo float64, radius float64, outline_colour string, sep_colour string, values []float64, fillcolours []string) *Dt_piechart

Create a pie chart given an array of values which are normalised into percentages of the overall total. Fill colours can be supplied on the call, or added later.

func (*Dt_piechart) Add_colour 

func (dt *Dt_piechart) Add_colour(cname string)

Add a fill colour value to the array. Cname may be a supported colour name (e.e. yellow) or a hex rgb value of the form #rrggbb or 0xrrggbb.

func (*Dt_piechart) Add_pctg 

func (dt *Dt_piechart) Add_pctg(p float64)

Add a percentage value to the array.

func (*Dt_piechart) Clear_values 

func (dt *Dt_piechart) Clear_values(clear_colours bool)

Clear the values and optionally the colours.

func (*Dt_piechart) Paint 

func (dt *Dt_piechart) Paint(gc sketch.Graphics_api, scale float64)

Draw the chart with it's current folours, and outline. If the visible attribute for the object is false, then it is not rendered.

func (*Dt_piechart) Set_delta_radius 

func (dt *Dt_piechart) Set_delta_radius(dr float64)

Adjust the current radius by the delta value dr

func (*Dt_piechart) Set_radius 

func (dt *Dt_piechart) Set_radius(r float64)

Set the radius to the given value r

func (*Dt_piechart) String 

func (dt *Dt_piechart) String() string

func (*Dt_piechart) To_json 

func (dt *Dt_piechart) To_json() (string, error)

To_json will generate a json string from this struct.

func (*Dt_piechart) XTo_json 

func (dt *Dt_piechart) XTo_json() string

type Dt_rect 

type Dt_rect struct {
	Dt_base // common fields and functions

	Fill_style int
	Fcolour    string // fill colour

	Height     float64
	Width      float64
	Line_style int
}

func Mk_rect 

func Mk_rect(xo float64, yo float64, height float64, width float64, outline_colour string, fill bool, fill_colour string) *Dt_rect

Mk_rect allows an instance of the rect struct to be created directly rather than creating a generic drawing thing. Xo,Yo is upper left corner.

func (*Dt_rect) Paint 

func (dt *Dt_rect) Paint(gc sketch.Graphics_api, scale float64)

Paint draws the rectangle according to the information in the struct.

func (*Dt_rect) Set_delta_hw 

func (dt *Dt_rect) Set_delta_hw(h float64, w float64)

h and w are delta values which are added to the current size.

func (*Dt_rect) Set_fill 

func (dt *Dt_rect) Set_fill(state bool)

Set the fill value. If true passed, then rectangle will be filled

func (*Dt_rect) Set_fill_colour 

func (dt *Dt_rect) Set_fill_colour(cname string)

Set the fill colour to use when the rectangle fill state is true.

func (*Dt_rect) Set_line_style 

func (dt *Dt_rect) Set_line_style(style int)

Set_line_style allows the style of the outline to be changed after the thing has been created. Expects one of the *_LINE constants.

func (*Dt_rect) Set_size 

func (dt *Dt_rect) Set_size(h float64, w float64)

Change the current height and width.

func (*Dt_rect) String 

func (dt *Dt_rect) String() string

func (*Dt_rect) To_json 

func (dt *Dt_rect) To_json() (string, error)

To_json will generate a json string from this struct.

type Dt_reg_polygon 

type Dt_reg_polygon struct {
	Dt_base // common fields and functions

	Fill_style int
	Fcolour    string // fill colour

	Points     []*sktools.Point
	Radius     float64
	Sides      int
	Line_style int
}

func Mk_def_poly 

func Mk_def_poly() (dt *Dt_reg_polygon)

Mk_def_poly creates a polygon struct with default (less than useful) values.

func Mk_reg_poly 

func Mk_reg_poly(xo float64, yo float64, radius float64, sides int, outline_colour string, fill bool, fill_colour string) *Dt_reg_polygon

Mk_rect allows an instance of the regular poly struct to be created directly rather than creating a generic drawing thing.

func (*Dt_reg_polygon) Paint 

func (dt *Dt_reg_polygon) Paint(gc sketch.Graphics_api, scale float64)

Paint draws the polygon according to the information in the struct.

func (*Dt_reg_polygon) Rotate 

func (dt *Dt_reg_polygon) Rotate(vertex float64, angle float64)

Rotate captures the information needed to rotate the triangle when painted. The rotation point is given as a vertex number (1, 2, 3 etc.) and to rotate round the centre of the triangle, the special vertex of 0 is used.

Some drawing things might treat a vertex of 1.5 to mean halfway between the first and second vertex, and others might ignore the fractional part all together.

func (*Dt_reg_polygon) Set_fill 

func (dt *Dt_reg_polygon) Set_fill(state bool)

Set the fill value. If true passed, then rectangle will be filled

func (*Dt_reg_polygon) Set_fill_colour 

func (dt *Dt_reg_polygon) Set_fill_colour(cname string)

Set the fill colour to use when the rectangle fill state is true.

func (*Dt_reg_polygon) Set_iscale 

func (dt *Dt_reg_polygon) Set_iscale(increment float64)

Set_iscale will set the drawing scale of the poligyon by adding the increment passed in to the current value.

func (*Dt_reg_polygon) Set_line_style 

func (dt *Dt_reg_polygon) Set_line_style(style int)

Set_line_style allows the style of the outline to be changed after the thing has been created. Expects one of the *_LINE constants.

func (*Dt_reg_polygon) Set_origin 

func (dt *Dt_reg_polygon) Set_origin(new_xo float64, new_yo float64)

Set a new orign for the drawing thing.

func (*Dt_reg_polygon) Set_scale 

func (dt *Dt_reg_polygon) Set_scale(new_scale float64)

Set_scale will set the drawing scale of the poligyon to the value passed in.

func (*Dt_reg_polygon) String 

func (dt *Dt_reg_polygon) String() string

func (*Dt_reg_polygon) To_json 

func (dt *Dt_reg_polygon) To_json() (string, error)

To_json will generate a json string from this struct.

type Dt_run_graph 

type Dt_run_graph struct {
	Dt_graph_base

	Line_styles []int // line style; one for each line
}

The struct used to manage the run graph. Line styles from the array are applied in order. If less styles are provided than data sets, the styles wrap. If no line styles are provided the default is a solid line.

func Mk_default_run_graph 

func Mk_default_run_graph() *Dt_run_graph

This generates a run graph struct with defaults. Likely this is used to create a graph overwhich a subset of json is used to populate only the desired changes to the default.

func (*Dt_run_graph) Paint 

func (dt *Dt_run_graph) Paint(gc sketch.Graphics_api, scale float64)

Paint will render the run graph using the graphics context (gc) passed in.

func (*Dt_run_graph) To_json 

func (dt *Dt_run_graph) To_json() (string, error)

Return json from the underlying drawing thing.

type Dt_tangle 

type Dt_tangle struct {
	Dt_base // common fields and functions

	Fill_style int
	Fcolour    string // fill colour

	Height       float64 // amuont the peak is shifted in the y direction from yo
	Base_len     float64
	Rise         float64 // rise of the second point from the pase y
	Peak_offset  float64 // amount the peak is shifted in the x direction from xo
	Align_centre bool    // if true, the centre of the triangle is positioned at Xo,Yo.
	Adjusted     bool    // set if adjusted x,y has been set
	Adjusted_xo  float64 // adjusted lower left for quick painting
	Adjusted_yo  float64
	Line_style   int // *_LINE consts

	Points []*sktools.Point // drawing points; scaled and rotated
}

func Mk_def_tangle 

func Mk_def_tangle() (dt *Dt_tangle)

Mk_def_tangle creates a default triangle struct.

func Mk_tangle 

func Mk_tangle(xo float64, yo float64, height float64, base_len float64, peak_off float64, align_centre bool, outline_colour string, fill bool, fill_colour string) *Dt_tangle

Mk_tangle creates a triangle given the coordinates and: 

the length of the base
the offset (x) of the peak
the height
the rise off of the base y for the second point

If align center is true, then the centre of the triangle is positioned at Xo,Yo rather than the leftmost vertex.

func (*Dt_tangle) Centre_xy 

func (dt *Dt_tangle) Centre_xy() (x float64, y float64)

Centre_xy computes the centroid center of the triangele; the intersection of the three lines from each of the vertices to the opposite edge's midpoint.

We do this by computing two of the lines' slopes (m1 and m2), then computing 'b' for the line which isn't from Xo,Yo. Given ths slopes and the y intercept of the second line, we can compute the center's x value (xc) which can be plugged back into one of the equations to compute yc.

The returned xc,yc are NOT ajusted based on the current Xo,Yo values, but are deltas: 

-add to Xo,Yo to find the center point in real coordinates
- subtract from Xo,Yo to find the  lower left of the triangle
  for painting when positioning by the center.

func (*Dt_tangle) Paint 

func (dt *Dt_tangle) Paint(gc sketch.Graphics_api, scale float64)

Paint draws the triangle according to the information in the struct.

func (*Dt_tangle) Set_delta_hb 

func (dt *Dt_tangle) Set_delta_hb(h float64, b float64)

Set_delta_hb changes the height and base length by a delta value (h and b).

func (*Dt_tangle) Set_fill 

func (dt *Dt_tangle) Set_fill(state bool)

Set_fill allows to turn on or off the fill property.

func (*Dt_tangle) Set_fill_colour 

func (dt *Dt_tangle) Set_fill_colour(cname string)

Set_fill_colour replaces the current colour with the colour passed in.

func (*Dt_tangle) Set_line_style 

func (dt *Dt_tangle) Set_line_style(style int)

Set_line_style allows the style of the outline to be changed after the thing has been created. Expects one of the *_LINE constants.

func (*Dt_tangle) Set_rot_angle 

func (dt *Dt_tangle) Set_rot_angle(new_angle float64)

Set_rot_angle allows other objects to set the rotation angle.

func (*Dt_tangle) Set_size 

func (dt *Dt_tangle) Set_size(h float64, b float64)

Set_size changes the current height and base length.

func (*Dt_tangle) String 

func (dt *Dt_tangle) String() string

func (*Dt_tangle) To_json 

func (dt *Dt_tangle) To_json() (string, error)

To_json will generate a json string from this struct.

type Dt_text 

type Dt_text struct {
	Dt_base // common fields and functions

	Text       string // the 'data' to display
	Font       string // Sans, Serif, are also legit
	Size       int
	Weight     int // stroke weight (bold-ness)
	Ital       bool
	Fill_style int    // ability to fill is a future thing
	Fcolour    string // fill colour
}

func Mk_text 

func Mk_text(xo float64, yo float64, size float64, font string, outline_colour string, fill bool, fill_colour string, text string) *Dt_text

Mk_text allows an instance of the text struct to be created directly rather than creating a generic drawing thing.

func (*Dt_text) Paint 

func (dt *Dt_text) Paint(gc sketch.Graphics_api, scale float64)

Paint draws the text according to the information in the struct.

func (*Dt_text) Set_data 

func (dt *Dt_text) Set_data(data_thing interface{})

Set_data allows the text, and text colour, associated with this dt to be changed. A string is accepted, and if it begins with "colourxxxxxx," then the characters up to the comma are used to set the colour. The xxxx can be a colour name or a hex rgb value if proceeded with a hash.

func (*Dt_text) Set_delta_hw 

func (dt *Dt_text) Set_delta_hw(dsize float64, dwidth float64)

h and w are delta values which are added to the current size. Currently delth width is ignored.

func (*Dt_text) Set_fill 

func (dt *Dt_text) Set_fill(state bool)

Set the fill value. If true passed, then text will be filled

func (*Dt_text) Set_fill_colour 

func (dt *Dt_text) Set_fill_colour(cname string)

Set the fill colour to use when the text fill state is true.

func (*Dt_text) Set_size 

func (dt *Dt_text) Set_size(size float64, width float64)

Change the current size. Width is ignored at the moment.

func (*Dt_text) String 

func (dt *Dt_text) String() string

func (*Dt_text) To_json 

func (dt *Dt_text) To_json() (string, error)

To_json will generate a json string from this struct.

type J2dt 

type J2dt struct {
	Kind int
}

Basic struct with ONLY the fields needed to determine kind.

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