A rendering engine library for Go supporting both SDL2 and WebAssembly (HTML Canvas) targets.
Nevar pievienot vairāk kā 25 tēmas Tēmai ir jāsākas ar burtu vai ciparu, tā var saturēt domu zīmes ('-') un var būt līdz 35 simboliem gara.
Noah Petherbridge b4a1979a8b Bugfix on space character pirms 4 mēnešiem
canvas Make it a Go module + minor tweaks pirms 1 gada
event Spacebar event pirms 4 mēnešiem
examples Change public API to use int instead of int32 everywhere pirms 1 gada
sdl Bugfix on space character pirms 4 mēnešiem
.gitignore Add WebAssembly Hello World Example pirms 1 gada
LICENSE.md Clean up repository for stand-alone release pirms 1 gada
README.md Change public API to use int instead of int32 everywhere pirms 1 gada
color.go Maximize SDL2 window pirms 10 mēnešiem
ellipse.go Better Ellipse Drawing Algorithm pirms 1 gada
functions.go Change public API to use int instead of int32 everywhere pirms 1 gada
go.mod Make it a Go module + minor tweaks pirms 1 gada
go.sum Maximize SDL2 window pirms 10 mēnešiem
image.go Make it a Go module + minor tweaks pirms 1 gada
interface.go Text.IsZero to check more values pirms 11 mēnešiem
point.go Add Point Comparator Function and Tests pirms 1 gada
point_test.go Add Point Comparator Function and Tests pirms 1 gada
rect_test.go Change public API to use int instead of int32 everywhere pirms 1 gada
shapes.go Change public API to use int instead of int32 everywhere pirms 1 gada
version.go Make it a Go module + minor tweaks pirms 1 gada

README.md

Render: Go Graphics Library

GoDoc

Render is a graphics rendering library for Go.

It supports SDL2 and HTML Canvas back-ends enabling its use for both desktop applications (Linux, Mac and Windows) and WebAssembly modules for running in the web browser.

Screenshot

Notice: github.com/kirsle/render is a mirror to the upstream repository at git.kirsle.net/go/render. Issues and pull requests will be accepted at GitHub.

Example

package main

import (
    "git.kirsle.net/go/render"
    "git.kirsle.net/go/render/sdl"
)

func main() {
    mw := sdl.New("Hello World", 320, 240)

    if err := mw.Setup(); err != nil {
        panic(err)
    }

    // Text that we're gonna draw in the window.
    text := render.Text{
        Text:         "Hello, world!",
        Size:         24,
        Color:        render.SkyBlue,
        Shadow:       render.Blue,
        FontFilename: "DejaVuSans.ttf",
    }

    // Compute the rendered size of the text.
    rect, _ := mw.ComputeTextRect(text)

    for {
        // Blank the window.
        mw.Clear(render.White)

        // Poll for events (mouse clicks, keyboard keys, etc.)
        ev, err := mw.Poll()
        if err != nil {
            panic(err)
        }

        // Escape key closes the window.
        if ev.Escape {
            mw.Teardown()
            break
        }

        // Get the window size.
        w, h := mw.WindowSize()

        // Draw the text centered in the window.
        mw.DrawText(text, render.NewPoint(
            (w/2) - (rect.W/2),
            (h/2) - (rect.H/2),
        ))

        mw.Present()
    }
}

See the examples/ directory for examples. More will come eventually, including some WebAssembly examples.

Project Status: Alpha

This module was written as part of my drawing-based maze game, code named Project: Doodle. It is currently in alpha status and its API may change and be cleaned up in the future.

Drawing Methods (Engine)

This package provides some basic primitive drawing methods which are implemented for SDL2 (desktops) and HTML Canvas (WebAssembly). See the render.Engine interface. The drawing methods supported are:

  • Clear(Color): blank the window and fill it with this color.
  • DrawPoint(Color, Point): draw a single pixel at a coordinate.
  • DrawLine(Color, A Point, B Point): draw a line between two points.
  • DrawRect(Color, Rect): draw a rectangle outline between two points.
  • DrawBox(Color, Rect): draw a filled rectangle between two points.
  • DrawText(Text, Point): draw text at a location.
  • StoreTexture(name string, image.Image): load a Go image.Image object into the engine as a “texture” that can be re-used and pasted on the canvas.
  • LoadTexture(filename string): load an image from disk into a texture.
  • Copy(Texturer, src Rect, dst Rect): copy a texture onto the canvas.

Drawing Types

This package defines a handful of types useful for drawing operations. See the godoc for full details.

  • Color: an RGBA color holding uint8 values for each channel.
    • NewRGBA(red, green, blue, alpha uint8) to construct a new color.
  • Point: holds an X,Y pair of coordinates.
  • Rect: holds an X,Y and a W,H value.
  • Text: holds text and configuration for rendering (color, stroke, shadow, size, etc.)

Shape Generator Functions

The render package includes a few convenience functions for drawing complex shapes.

The generator functions return a channel that yields all of the Points that should be drawn to complete the shape. Example:

var (
    A Point = render.NewPoint(10, 10)
    B Point = render.NewPoint(15, 20)
)

for pt := range render.IterLine(A, B) {
    engine.DrawPoint(render.Red, pt)
}
  • IterLine(A Point, B Point): draw a line from A to B.
  • IterRect(A Point, B Point): iterate all the points to draw a rectangle.
  • IterEllipse(A Point, B Point): draw an elipse fitting inside the rectangle bounded by points A and B.

License

MIT.