Table of Contents

• 1. currentlinecap
  • 1.1. Syntax
  • 1.2. Stack Effects
  • 1.3. Description
  • 1.4. PostScript Level
  • 1.5. Examples
  • 1.6. Common Use Cases
    • 1.6.1. Cap State Preservation
    • 1.6.2. Cap-Dependent Rendering
    • 1.6.3. Style Detection
  • 1.7. Common Pitfalls
  • 1.8. Error Conditions
  • 1.9. Implementation Notes
  • 1.10. Line Cap Styles
  • 1.11. See Also

1. currentlinecap

Returns current line cap style.

1.1. Syntax

– currentlinecap → int

1.2. Stack Effects

Table 1. Before

Level	Object
(empty)	–

Table 2. After

Level	Object
0	int (0, 1, or 2)

1.3. Description

currentlinecap returns the current line cap parameter from the graphics state. This is the value most recently set by setlinecap.

Cap styles:

• 0 = Butt cap (squared off at endpoint)

• 1 = Round cap (semicircular)

• 2 = Projecting square cap (extends beyond endpoint)

1.4. PostScript Level

Level 1 and later

1.5. Examples

Querying current line cap

1 setlinecap
currentlinecap
% Stack: 1

Saving and restoring line cap

currentlinecap          % Save
/savedCap exch def

2 setlinecap            % Change to square
drawLines

savedCap setlinecap     % Restore

Conditional drawing

currentlinecap 1 eq {
  % Round caps - draw dots
  drawDottedLine
} {
  % Other caps - draw dashed
  drawDashedLine
} ifelse

1.6. Common Use Cases

1.6.1. Cap State Preservation

/DrawWithRoundCaps {
  currentlinecap        % Save
  1 setlinecap          % Round

  drawShape

  setlinecap            % Restore
} def

1.6.2. Cap-Dependent Rendering

/DrawLineCap {
  currentlinecap
  dup 0 eq {
    % Butt - draw arrow
    drawArrow
  } if
  dup 1 eq {
    % Round - draw circle
    drawCircle
  } if
  2 eq {
    % Square - draw square
    drawSquare
  } if
} def

1.6.3. Style Detection

/IsRoundCap {
  currentlinecap 1 eq
} def

IsRoundCap {
  % Use round cap drawing
} {
  % Use other cap drawing
} ifelse

1.7. Common Pitfalls

Only Applies to Open Paths - Line caps don’t affect closed paths.

2 setlinecap
currentlinecap  % Returns 2
% But closed paths won't show square caps

Use for Dots - Round caps (1) with zero-length lines make perfect dots.

1.8. Error Conditions

Error	Condition
[stackoverflow]	No room on operand stack

1.9. Implementation Notes

• Very fast query operation

• No modification to graphics state

• Returns integer 0, 1, or 2

• Default value is typically 0 (butt)

• Widely supported (Level 1)

1.10. Line Cap Styles

Butt (0):     ├─────┤
Round (1):    (─────)
Square (2):   [─────]

1.11. See Also

• setlinecap - Set line cap style

• currentlinejoin - Get line join style

• currentlinewidth - Get line width

• currentdash - Get dash pattern