Module raster 

Translation of vector shapes into discrete pixels in the framebuffer.

Rasterization proceeds by turning a primitive such as a triagle into a sequence of scanlines, each corresponding to a horizontal span of pixels covered by the primitive on a given line. The scanlines, in turn, are converted into a series of fragments that represent potentially drawn pixels.

If depth testing (z-buffering) is enabled, the fragments are then tested against the current depth value in their position. For each fragment that passes the depth test, a color is computed by the fragment shader and written into the framebuffer. Fragments that fail the test are discarded.

Structs

Frag

A fragment, or a single “pixel” in a rasterized primitive.

Scanline

A horizontal, 1-pixel-thick “slice” of a primitive being rasterized.

ScanlineIter

Iterator emitting scanlines, linearly interpolating values between the left and right endpoints as it goes.

Functions

line

Rasterizes a one-pixel-thick line between two vertices.

scan

Returns an iterator that emits a scanline for each line from y0 to y1, interpolating varyings from l0 to l1 on the left and from r0 to r1 on the right side.

tri_fill

Rasterizes a filled triangle defined by three vertices.

Type Aliases

ScreenPt

Point in screen space. x and y are viewport pixel coordinates, z is depth.

Varyings

Values to interpolate across a rasterized primitive.