Example 4 — Square with Hole (Combine)

Created: 2026-05-27 · Updated: 2026-05-27

A circle is punched out of a square — Combine creates the hole. The result is a shape with a true geometric cutout that remains transparent even over colored backgrounds.

Result

Code

/* PARAMS */
float left  = 120f;
float top   = 100f;
float size  = 180f;
var   color = System.Drawing.Color.FromArgb(39, 174, 96);
/* END PARAMS */

int fillRgb = System.Drawing.ColorTranslator.ToOle(color);
int lineRgb = System.Drawing.ColorTranslator.ToOle(
    System.Drawing.Color.FromArgb(27, 120, 67));
float cx   = left + size / 2f;
float cy   = top  + size / 2f;
float hole = size * 0.35f;

// Square
var oSquare = ppptools.AddRect(left, top, size, size);

// Hole circle (centered in square)
var oHole = ppptools.AddOval(cx - hole/2f, cy - hole/2f, hole, hole);

// Combine — circle is punched out of the square
oSquare.Select(MsoTriState.msoTrue);
oHole.Select(MsoTriState.msoFalse);
ppptools.Combine();

foreach (dynamic sh in ppptools.GetSelectedRange())
{
    sh.Name               = "SquareWithHole";
    sh.Fill.ForeColor.RGB = fillRgb;
    sh.Fill.Transparency  = 0f;
    sh.Line.ForeColor.RGB = lineRgb;
    sh.Line.Weight        = 1.5f;
}

Step-by-Step Explanation

1. Pre-computing Colors and Dimensions

int fillRgb = System.Drawing.ColorTranslator.ToOle(color);
int lineRgb = System.Drawing.ColorTranslator.ToOle(
    System.Drawing.Color.FromArgb(27, 120, 67));
float cx   = left + size / 2f;
float cy   = top  + size / 2f;
float hole = size * 0.35f;

All derived values are stored as local variables before creating any shapes. This is cleaner than nesting calculations inside method calls.

cx / cy — center of the square (for centering the hole)
hole = size * 0.35f — hole diameter = 35% of the square's size

2. Creating the Square

var oSquare = ppptools.AddRect(left, top, size, size);

width == height → perfect square (same principle as the circle in Example 2).

3. Creating and Centering the Hole Circle

var oHole = ppptools.AddOval(cx - hole/2f, cy - hole/2f, hole, hole);

The hole circle sits exactly at the center of the square. The center-point pattern from Example 2 is reused: cx - hole/2f.

4. The Combine Operation — How It Differs from Union

oSquare.Select(MsoTriState.msoTrue);
oHole.Select(MsoTriState.msoFalse);
ppptools.Combine();

Combine works like Union, except: areas where the shapes overlap are punched out (become transparent). The result is a shape with a true geometric hole.

Operation	Overlapping Area
`Union`	stays filled
`Combine`	becomes a hole (transparent)
`Intersect`	only the overlap remains
`Subtract`	overlap is removed from the first shape

Selection Order Matters

With Combine, the shape selected first (msoTrue) determines the style.
Both shapes participate in the cutout — but the first shape "wins" for styling.

5. Styling the Result Shape

foreach (dynamic sh in ppptools.GetSelectedRange())
{
    sh.Name               = "SquareWithHole";
    sh.Fill.ForeColor.RGB = fillRgb;
    sh.Fill.Transparency  = 0f;
    sh.Line.ForeColor.RGB = lineRgb;
    sh.Line.Weight        = 1.5f;
}

The hole is not noticeable when the slide background is white. Over a colored background or image, the true cutout becomes visible.

What's Special About This Example

Combine ≠ Union — same syntax, but overlapping areas become holes, not solid fill.
True geometric hole — not a white circle on top, but a real transparent cutout in the shape geometry. Verify it: change the slide background color → the hole reveals the background.
lineRgb defined directly — the darker border color (27, 120, 67) is a manually darkened shade of the fill color (39, 174, 96).
Line.Weight = 1.5f — a thin border that makes the hole outline visible.

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