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Kavachकवच

Standard Library: std.gpu

● Intermediate5 min

Every type, method and function of std.gpu: what the spec lists, then each declaration in its source, with its examples and the line that declares it.

Spec 14.24 · learn it in GPU Screens.

A declaration below shows what a program writes against: a type's fields, a function's parameters, what it gives, its contracts (require, ensure) and its examples. kavach test runs every example, so each one is true of the code.

spec 14.24 · std.gputhe examples, tested

What the spec lists

Function or methodGives
gpu.screen(win) -> Screen ! GpuErrorWhat draws into the window win, using the program's GPU
screen.frame() -> Frame ! GpuErrorThe next picture to draw, as big as the window is now. It waits for the screen's next refresh when the last picture isn't shown yet (vsync), so a loop of frames runs at the screen's rate
frame.clear(r, g, b)Fills the picture with one color; each part is a Float32 from 0 to 1
frame.draw(pipeline, vertices)Draws vertices through pipeline (15.3)
frame.draw(pipeline, vertices, instances: items)The same once for each item of items, which the vertex fn gets as its second parameter
frame.draw(pipeline, vertices, instances: items, with: shared)The same, shared given to every vertex as the vertex fn's last parameter
frame.show()Puts the picture on the screen
gpu.pipeline(vertex_fn, fragment_fn) -> PipelineA pipeline drawing triangles with a gpu vertex fn and a gpu fragment fn (15.3)

std.gpu · gpu.kav

use std.gpu: 3 types and 1 function. stdlib/gpu/gpu.kav

GpuError type

Why there is nothing to draw into: no GPU, a window that can't be drawn into, or a frame that can't be had now.

pub type GpuError = Unavailable(reason: String)

Screen type

What draws into a window.

pub type Screen: Drop {
    id: Int
    window: Int
}

frame method

The next picture to draw, as big as the window is now; it waits for the screen's next refresh when the last picture isn't shown yet.

pub fn frame(self) -> Frame ! GpuError uses Window

Frame type

A picture being drawn. One not shown before its last holder ends is thrown away.

pub type Frame: Drop {
    id: Int
}

clear method

Fills the picture with one color, each part from 0 to 1.

pub fn clear(self, r: Float32, g: Float32, b: Float32) uses Window
    require r >= 0.0 and r <= 1.0 and g >= 0.0 and g <= 1.0 and b >= 0.0 and b <= 1.0

show method

Puts the picture on the screen.

pub fn show(self) uses Window

screen function

What draws into the window win, using the program's GPU.

pub fn screen(win: AppWindow) -> Screen ! GpuError uses Window