viewport

Tag: viewport
Parent tag: viewports
Attributes:

• name (string)

Child tags:

• CLEAR_COLOR (vec4) – r,g,b,a(optional)
• ORIGIN (vec2) – x,y (optional)
• SIZE (vec2) – width, height (optional)
• RATIO (float)- optional

The viewport tag defines the background color and dimensions of the viewport.

The background is defined with the tag CLEAR_COLOR, which has a vec4 has an attribute.

Both origin and size can be defined with relative or absolute values. If a value is smaller than, or equal to, 1 it is assumed to be relative.

If ratio is defined the height of the viewport is computed as absolute_width * ratio.

Example:

In the above definition the viewport the width is interpreted as relative ( <= 1) and the height is absolute.

In the second example the viewport’s width will be 25% of the window’s width. Assuming that the window is 1000 pixels wide, the width will be 250 pixels. The height can then be computed as 250*2 = 500 pixels.

Several viewports can be defined as shown in the figure below.

The code to define the above viewports is:

See the example project “shadows” in GitHub