Module cairo_helpers
Cairo helper functions
Functions
| create_cr(conky_window) | Get a new drawing context for the given conky window. |
| polygon(cr, coordinates) | Draw a polygon with the given vertices. |
| show_point(cr, x, y[, size=4[, r=1[, g=0[, b=0[, a=0.7]]]]]) | Draw a little cross where a given point is. |
| alpha_gradient(cr, x1, y1, x2, y2, r, g, b, stops) | Set a single color gradient with varying opacity on the given cairo drawing context. |
| alpha_gradient_radial(cr, x1, y1, inner_radius, x2, y2, outer_radius, r, g, b, stops) | Set a radial single color gradient with varying opacity on the given cairo drawing context. |
| set_font(cr, font_family, font_size[, font_slant[, font_weight]]) | Select font settings for given cairo drawing context |
| font_extents(font_family, font_size[, font_slant[, font_weight]]) | Get cairo_font_extents_t for a given font with size. |
| write_left(cr, x, y, text) | Write text left-aligned (to the right of given x). |
| write_right(cr, x, y, text) | Write text right-aligned (to the left of given x). |
| write_centered(cr, mx, y, text) | Write text centered (spread evenly towards both sides of mx). |
| write_middle(cr, mx, my, text) | Write text centered horizontally and vertically on the given point mx, my. |
Local Functions
| text_extents(cr, text) | Get cairo_text_extents_t for given text on given cairo drawing surface with its currently set font. |
| round_coords(cr, x, y) | Round coordinates to even pixel values See https://www.cairographics.org/FAQ/#sharp_lines See https://scriptinghelpers.org/questions/4850/how-do-i-round-numbers-in-lua-answered |
Functions
- create_cr(conky_window)
-
Get a new drawing context for the given conky window.
Be sure to call cairo_destroy(cr) when you're done.
Parameters:
- conky_window global conky_window
Returns:
-
cairo_t
- polygon(cr, coordinates)
-
Draw a polygon with the given vertices.
Parameters:
- cr cairo_t
- coordinates {number,...} of vertices (x1, y1, x2, y2, ...)
- show_point(cr, x, y[, size=4[, r=1[, g=0[, b=0[, a=0.7]]]]])
-
Draw a little cross where a given point is. Useful for debugging.
By default the cross is red.
Parameters:
- cr cairo_t
- x number x coordinate of point
- y number y coordinate of point
- size number line length of cross (default 4)
- r number red color component (default 1)
- g number green color component (default 0)
- b number blue color component (default 0)
- a number alpha color compnent (transparency) (default 0.7)
- alpha_gradient(cr, x1, y1, x2, y2, r, g, b, stops)
-
Set a single color gradient with varying opacity
on the given cairo drawing context.
Parameters:
- cr cairo_t
- x1 number x coordinate of gradient start
- y1 number y coordinate of gradient start
- x2 number x coordinate of gradient end
- y2 number y coordinate of gradient end
- r number red color component
- g number green color component
- b number blue color component
- stops {number,...} list of offset & alpha value pairs offset between 0 and 1 describes position in the gradient alpha between 0 and 1 describes opacity at given offset. Note: For high/low alpha values the brightness may be emphasized by color variation.
- alpha_gradient_radial(cr, x1, y1, inner_radius, x2, y2, outer_radius, r, g, b, stops)
-
Set a radial single color gradient with varying opacity
on the given cairo drawing context.
Parameters:
- cr cairo_t
- x1 number x coordinate of inner circle center point
- y1 number y coordinate of inner circle center point
- inner_radius number
- x2 number x coordinate of outer circle center point
- y2 number y coordinate of outer circle center point
- outer_radius number
- r number red color component
- g number green color component
- b number blue color component
- stops {number,...} list of offset & alpha value pairs offset between 0 and 1 describes position in the gradient alpha between 0 and 1 describes opacity at given offset. Note: For high/low alpha values the brightness may be emphasized by color variation.
- set_font(cr, font_family, font_size[, font_slant[, font_weight]])
-
Select font settings for given cairo drawing context
Parameters:
- cr cairo_t
- font_family string
- font_size int
- font_slant optional cairo_font_slant_t (default: CAIRO_FONT_SLANT_NORMAL) (optional)
- font_weight optional cairo_font_weight_t (default: CAIRO_FONT_WEIGHT_NORMAL) (optional)
- font_extents(font_family, font_size[, font_slant[, font_weight]])
-
Get cairo_font_extents_t for a given font with size.
Use this, for example, to determine line-height.
see https://cairographics.org/manual/cairo-cairo-scaled-font-t.html#cairo-font-extents-t
Parameters:
- font_family string
- font_size int
- font_slant optional cairo_font_slant_t (default: CAIRO_FONT_SLANT_NORMAL) (optional)
- font_weight optional cairo_font_weight_t (default: CAIRO_FONT_WEIGHT_NORMAL) (optional)
Returns:
-
cairo_font_extents_t
- write_left(cr, x, y, text)
-
Write text left-aligned (to the right of given x).
Parameters:
- cr cairo_t
- x number start of the written text
- y number coordinate of the baseline on top of which the text will be written
- text string
- write_right(cr, x, y, text)
-
Write text right-aligned (to the left of given x).
Parameters:
- cr cairo_t
- x number end of the written text
- y number coordinate of the baseline on top of which the text will be written
- text string
- write_centered(cr, mx, y, text)
-
Write text centered (spread evenly towards both sides of mx).
Parameters:
- cr cairo_t
- mx number horizontal center of the written text
- y number coordinate of the baseline on top of which the text will be written
- text string
- write_middle(cr, mx, my, text)
-
Write text centered horizontally and vertically on the given point mx, my.
Parameters:
- cr cairo_t
- mx number horizontal center of the written text
- my number vertical center of the written text
- text string
Local Functions
- text_extents(cr, text)
-
Get cairo_text_extents_t for given text on given cairo drawing surface
with its currently set font.
See https://cairographics.org/manual/cairo-cairo-scaled-font-t.html#cairo-text-extents-t
Parameters:
- cr cairo_t
- text string
Returns:
-
cairo_text_extents_t
- round_coords(cr, x, y)
-
Round coordinates to even pixel values
See https://www.cairographics.org/FAQ/#sharp_lines
See https://scriptinghelpers.org/questions/4850/how-do-i-round-numbers-in-lua-answered
Parameters:
- cr cairo_t
- x number horizontal pixel coord value
- y number vertical pixel coord value