ebiten/doc.go
Hajime Hoshi b1d7a5f595 shaderir/glsl: Enable dFdx for WebGL
With WebGL1, an extension is required for dFdx. On the other hand,
with WebGL2, GLSL ES 300 is required and the extension is forbidden.
This change fixes shaderir/glsl to switch the output depends on the
WebGL version.

This change also adds a new build tag 'ebitenwebgl1' forcing WebGL 1.

Updates #1404
2020-11-21 19:07:54 +09:00

82 lines
3.5 KiB
Go

// Copyright 2014 Hajime Hoshi
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
// Package ebiten provides graphics and input API to develop a 2D game.
//
// You can start the game by calling the function RunGame.
//
// // Game implements ebiten.Game interface.
// type Game struct{}
//
// // Update proceeds the game state.
// // Update is called every tick (1/60 [s] by default).
// func (g *Game) Update() error {
// // Write your game's logical update.
// return nil
// }
//
// // Draw draws the game screen.
// // Draw is called every frame (typically 1/60[s] for 60Hz display).
// func (g *Game) Draw(screen *ebiten.Image) {
// // Write your game's rendering.
// }
//
// // Layout takes the outside size (e.g., the window size) and returns the (logical) screen size.
// // If you don't have to adjust the screen size with the outside size, just return a fixed size.
// func (g *Game) Layout(outsideWidth, outsideHeight int) (screenWidth, screenHeight int) {
// return 320, 240
// }
//
// func main() {
// game := &Game{}
// // Sepcify the window size as you like. Here, a doulbed size is specified.
// ebiten.SetWindowSize(640, 480)
// ebiten.SetWindowTitle("Your game's title")
// // Call ebiten.RunGame to start your game loop.
// if err := ebiten.RunGame(game); err != nil {
// log.Fatal(err)
// }
// }
//
// In the API document, 'the main thread' means the goroutine in init(), main() and their callees without 'go'
// statement. It is assured that 'the main thread' runs on the OS main thread. There are some Ebiten functions (e.g.,
// DeviceScaleFactor) that must be called on the main thread under some conditions (typically, before ebiten.RunGame
// is called).
//
// Environment variables
//
// `EBITEN_SCREENSHOT_KEY` environment variable specifies the key
// to take a screenshot. For example, if you run your game with
// `EBITEN_SCREENSHOT_KEY=q`, you can take a game screen's screenshot
// by pressing Q key. This works only on desktops.
//
// `EBITEN_INTERNAL_IMAGES_KEY` environment variable specifies the key
// to dump all the internal images. This is valid only when the build tag
// 'ebitendebug' is specified. This works only on desktops.
//
// Build tags
//
// `ebitendebug` outputs a log of graphics commands. This is useful to know what happens in Ebiten. In general, the
// number of graphics commands affects the performance of your game.
//
// `ebitengl` forces to use OpenGL in any environments.
//
// `ebitenwebgl1` forces to use WebGL 1 on browsers.
//
// `ebitensinglethread` disables Ebiten's thread safety to unlock maximum performance. If you use this you will have
// to manage threads yourself. Functions like IsKeyPressed will no longer be concurrent-safe with this build tag.
// They must be called from the main thread or the same goroutine as the given game's callback functions like Update
// to RunGame.
package ebiten