mstar/canvas
1
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity Actions

added a glfwcanvas subpackage

Browse source
This commit is contained in:
Thomas Friedel 2018-10-20 14:42:29 +02:00
parent 32bbbdd7c8
commit 93d30a1ff7
4 changed files with 387 additions and 4 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

6
README.md
View file

@ -10,15 +10,15 @@ Whereas the Javascript API uses a context that all draw calls go to, here all dr
The library is intended to provide decent performance. Obviously it will not be able to rival hand coded OpenGL for a given purpose, but for many purposes it will be enough. It can also be combined with hand coded OpenGL.
# SDL convenience package
# SDL/GLFW convenience packages
The sdlcanvas subpackage provides a very simple way to get started with just a few lines of code. As the name implies it is based on the SDL library. It creates a window for you and gives you a canvas to draw with.
The sdlcanvas and glfwcanvas subpackages provide a very simple way to get started with just a few lines of code. As the names imply they are based on the SDL library and the GLFW library respectively. They create a window for you and give you a canvas to draw with.
# OS support
- Linux
- Windows
- OSX
- macOS
- Android
- iOS

2
examples/glfw/glfw.go
View file

@ -13,7 +13,7 @@ import (
func main() {
runtime.LockOSThread()
// init SDL
// init GLFW
err := glfw.Init()
if err != nil {
log.Fatalf("Error initializing GLFW: %v", err)

167
glfwcanvas/glfwcanvas.go Normal file
View file

@ -0,0 +1,167 @@
package glfwcanvas
import (
"fmt"
_ "image/gif" // Imported here so that applications based on this package support these formats by default
_ "image/jpeg"
_ "image/png"
"log"
"math"
"runtime"
"time"
"github.com/go-gl/gl/v3.2-core/gl"
"github.com/go-gl/glfw/v3.2/glfw"
"github.com/tfriedel6/canvas"
"github.com/tfriedel6/canvas/glimpl/gogl"
)
// Window represents the opened window with GL context. The Mouse* and Key*
// functions can be set for callbacks
type Window struct {
Window *glfw.Window
canvas *canvas.Canvas
frameTimes [10]time.Time
frameIndex int
frameCount int
fps float32
close bool
MouseDown func(button, x, y int)
MouseMove func(x, y int)
MouseUp func(button, x, y int)
MouseWheel func(x, y int)
KeyDown func(scancode int, rn rune, name string)
KeyUp func(scancode int, rn rune, name string)
KeyChar func(rn rune)
SizeChange func(w, h int)
}
// CreateWindow creates a window using SDL and initializes the OpenGL context
func CreateWindow(w, h int, title string) (*Window, *canvas.Canvas, error) {
runtime.LockOSThread()
// init GLFW
err := glfw.Init()
if err != nil {
log.Fatalf("Error initializing GLFW: %v", err)
}
// the stencil size setting is required for the canvas to work
glfw.WindowHint(glfw.StencilBits, 8)
glfw.WindowHint(glfw.DepthBits, 0)
// create window
window, err := glfw.CreateWindow(w, h, title, nil, nil)
if err != nil {
log.Fatalf("Error creating window: %v", err)
}
window.MakeContextCurrent()
// init GL
err = gl.Init()
if err != nil {
log.Fatalf("Error initializing GL: %v", err)
}
// set vsync on, enable multisample (if available)
glfw.SwapInterval(1)
gl.Enable(gl.MULTISAMPLE)
// load canvas GL assets
err = canvas.LoadGL(glimplgogl.GLImpl{})
if err != nil {
log.Fatalf("Error loading canvas GL assets: %v", err)
}
err = canvas.LoadGL(glimplgogl.GLImpl{})
if err != nil {
return nil, nil, fmt.Errorf("Error loading canvas GL assets: %v", err)
}
cv := canvas.New(0, 0, w, h)
wnd := &Window{
Window: window,
canvas: cv,
}
var mx, my int
window.SetMouseButtonCallback(func(w *glfw.Window, button glfw.MouseButton, action glfw.Action, mod glfw.ModifierKey) {
if action == glfw.Press && wnd.MouseDown != nil {
wnd.MouseDown(int(button), mx, my)
} else if action == glfw.Release && wnd.MouseUp != nil {
wnd.MouseUp(int(button), mx, my)
}
})
window.SetCursorPosCallback(func(w *glfw.Window, xpos float64, ypos float64) {
mx, my = int(math.Round(xpos)), int(math.Round(ypos))
if wnd.MouseMove != nil {
wnd.MouseMove(mx, my)
}
})
window.SetScrollCallback(func(w *glfw.Window, xoff float64, yoff float64) {
if wnd.MouseWheel != nil {
wnd.MouseWheel(int(math.Round(xoff)), int(math.Round(yoff)))
}
})
window.SetKeyCallback(func(w *glfw.Window, key glfw.Key, scancode int, action glfw.Action, mods glfw.ModifierKey) {
if action == glfw.Press && wnd.KeyDown != nil {
wnd.KeyDown(scancode, keyRune(key), keyName(key))
} else if action == glfw.Release && wnd.KeyUp != nil {
wnd.KeyUp(scancode, keyRune(key), keyName(key))
}
})
window.SetCharCallback(func(w *glfw.Window, char rune) {
if wnd.KeyChar != nil {
wnd.KeyChar(char)
}
})
window.SetSizeCallback(func(w *glfw.Window, width int, height int) {
if wnd.SizeChange != nil {
wnd.SizeChange(width, height)
}
})
return wnd, cv, nil
}
// FPS returns the frames per second (averaged over 10 frames)
func (wnd *Window) FPS() float32 {
return wnd.fps
}
// Close can be used to end a call to MainLoop
func (wnd *Window) Close() {
wnd.close = true
}
// StartFrame handles events and gets the window ready for rendering
func (wnd *Window) StartFrame() {
wnd.Window.MakeContextCurrent()
glfw.PollEvents()
}
// FinishFrame updates the FPS count and displays the frame
func (wnd *Window) FinishFrame() {
now := time.Now()
wnd.frameTimes[wnd.frameIndex] = now
wnd.frameIndex++
wnd.frameIndex %= len(wnd.frameTimes)
if wnd.frameCount < len(wnd.frameTimes) {
wnd.frameCount++
} else {
diff := now.Sub(wnd.frameTimes[wnd.frameIndex]).Seconds()
wnd.fps = float32(wnd.frameCount-1) / float32(diff)
}
wnd.Window.SwapBuffers()
}
// MainLoop runs a main loop and calls run on every frame
func (wnd *Window) MainLoop(run func()) {
for !wnd.close {
wnd.StartFrame()
run()
wnd.FinishFrame()
}
}

216
glfwcanvas/keynames.go Normal file
View file

@ -0,0 +1,216 @@
package glfwcanvas
import "github.com/go-gl/glfw/v3.2/glfw"
var keyNameMap [347]string
var keyRuneMap [347]rune
func init() {
keyNameMap[glfw.KeyEscape] = "Escape"
keyNameMap[glfw.Key0] = "Digit0"
keyNameMap[glfw.Key1] = "Digit1"
keyNameMap[glfw.Key2] = "Digit2"
keyNameMap[glfw.Key3] = "Digit3"
keyNameMap[glfw.Key4] = "Digit4"
keyNameMap[glfw.Key5] = "Digit5"
keyNameMap[glfw.Key6] = "Digit6"
keyNameMap[glfw.Key7] = "Digit7"
keyNameMap[glfw.Key8] = "Digit8"
keyNameMap[glfw.Key9] = "Digit9"
keyNameMap[glfw.KeyMinus] = "Minus"
keyNameMap[glfw.KeyEqual] = "Equal"
keyNameMap[glfw.KeyBackspace] = "Backspace"
keyNameMap[glfw.KeyTab] = "Tab"
keyNameMap[glfw.KeyQ] = "KeyQ"
keyNameMap[glfw.KeyW] = "KeyW"
keyNameMap[glfw.KeyE] = "KeyE"
keyNameMap[glfw.KeyR] = "KeyR"
keyNameMap[glfw.KeyT] = "KeyT"
keyNameMap[glfw.KeyY] = "KeyY"
keyNameMap[glfw.KeyU] = "KeyU"
keyNameMap[glfw.KeyI] = "KeyI"
keyNameMap[glfw.KeyO] = "KeyO"
keyNameMap[glfw.KeyP] = "KeyP"
keyNameMap[glfw.KeyLeftBracket] = "BracketLeft"
keyNameMap[glfw.KeyRightBracket] = "BracketRight"
keyNameMap[glfw.KeyEnter] = "Enter"
keyNameMap[glfw.KeyLeftControl] = "ControlLeft"
keyNameMap[glfw.KeyA] = "KeyA"
keyNameMap[glfw.KeyS] = "KeyS"
keyNameMap[glfw.KeyD] = "KeyD"
keyNameMap[glfw.KeyF] = "KeyF"
keyNameMap[glfw.KeyG] = "KeyG"
keyNameMap[glfw.KeyH] = "KeyH"
keyNameMap[glfw.KeyJ] = "KeyJ"
keyNameMap[glfw.KeyK] = "KeyK"
keyNameMap[glfw.KeyL] = "KeyL"
keyNameMap[glfw.KeySemicolon] = "Semicolon"
keyNameMap[glfw.KeyApostrophe] = "Quote"
keyNameMap[glfw.KeyGraveAccent] = "Backquote"
keyNameMap[glfw.KeyLeftShift] = "ShiftLeft"
keyNameMap[glfw.KeyBackslash] = "Backslash"
keyNameMap[glfw.KeyZ] = "KeyZ"
keyNameMap[glfw.KeyX] = "KeyX"
keyNameMap[glfw.KeyC] = "KeyC"
keyNameMap[glfw.KeyV] = "KeyV"
keyNameMap[glfw.KeyB] = "KeyB"
keyNameMap[glfw.KeyN] = "KeyN"
keyNameMap[glfw.KeyM] = "KeyM"
keyNameMap[glfw.KeyComma] = "Comma"
keyNameMap[glfw.KeyPeriod] = "Period"
keyNameMap[glfw.KeySlash] = "Slash"
keyNameMap[glfw.KeyRightShift] = "RightShift"
keyNameMap[glfw.KeyKPMultiply] = "NumpadMultiply"
keyNameMap[glfw.KeyLeftAlt] = "AltLeft"
keyNameMap[glfw.KeySpace] = "Space"
keyNameMap[glfw.KeyCapsLock] = "CapsLock"
keyNameMap[glfw.KeyF1] = "F1"
keyNameMap[glfw.KeyF2] = "F2"
keyNameMap[glfw.KeyF3] = "F3"
keyNameMap[glfw.KeyF4] = "F4"
keyNameMap[glfw.KeyF5] = "F5"
keyNameMap[glfw.KeyF6] = "F6"
keyNameMap[glfw.KeyF7] = "F7"
keyNameMap[glfw.KeyF8] = "F8"
keyNameMap[glfw.KeyF9] = "F9"
keyNameMap[glfw.KeyF10] = "F10"
keyNameMap[glfw.KeyPause] = "Pause"
keyNameMap[glfw.KeyScrollLock] = "ScrollLock"
keyNameMap[glfw.KeyKP7] = "Numpad7"
keyNameMap[glfw.KeyKP8] = "Numpad8"
keyNameMap[glfw.KeyKP9] = "Numpad9"
keyNameMap[glfw.KeyKPSubtract] = "NumpadSubtract"
keyNameMap[glfw.KeyKP4] = "Numpad4"
keyNameMap[glfw.KeyKP5] = "Numpad5"
keyNameMap[glfw.KeyKP6] = "Numpad6"
keyNameMap[glfw.KeyKPAdd] = "NumpadAdd"
keyNameMap[glfw.KeyKP1] = "Numpad1"
keyNameMap[glfw.KeyKP2] = "Numpad2"
keyNameMap[glfw.KeyKP3] = "Numpad3"
keyNameMap[glfw.KeyKP0] = "Numpad0"
keyNameMap[glfw.KeyKPDecimal] = "NumpadDecimal"
keyNameMap[glfw.KeyPrintScreen] = "PrintScreen"
// keyNameMap[glfw.KeyNonUSBackslash] = "IntlBackslash"
keyNameMap[glfw.KeyF11] = "F11"
keyNameMap[glfw.KeyF12] = "F12"
keyNameMap[glfw.KeyKPEqual] = "NumpadEqual"
keyNameMap[glfw.KeyF13] = "F13"
keyNameMap[glfw.KeyF14] = "F14"
keyNameMap[glfw.KeyF15] = "F15"
keyNameMap[glfw.KeyF16] = "F16"
keyNameMap[glfw.KeyF17] = "F17"
keyNameMap[glfw.KeyF18] = "F18"
keyNameMap[glfw.KeyF19] = "F19"
// keyNameMap[glfw.KeyUndo] = "Undo"
// keyNameMap[glfw.KeyPaste] = "Paste"
// keyNameMap[glfw.KeyAudioNext] = "MediaTrackPrevious"
// keyNameMap[glfw.KeyCut] = "Cut"
// keyNameMap[glfw.KeyCopy] = "Copy"
// keyNameMap[glfw.KeyAudioNext] = "MediaTrackNext"
keyNameMap[glfw.KeyKPEnter] = "NumpadEnter"
keyNameMap[glfw.KeyRightControl] = "ControlRight"
// keyNameMap[glfw.KeyMute] = "AudioVolumeMute"
// keyNameMap[glfw.KeyAudioPlay] = "MediaPlayPause"
// keyNameMap[glfw.KeyAudioStop] = "MediaStop"
// keyNameMap[glfw.KeyVolumeDown] = "AudioVolumeDown"
// keyNameMap[glfw.KeyVolumeUp] = "AudioVolumeUp"
keyNameMap[glfw.KeyKPDivide] = "NumpadDivide"
keyNameMap[glfw.KeyRightAlt] = "AltRight"
// keyNameMap[glfw.KeyHelp] = "Help"
keyNameMap[glfw.KeyHome] = "Home"
keyNameMap[glfw.KeyUp] = "ArrowUp"
keyNameMap[glfw.KeyPageUp] = "PageUp"
keyNameMap[glfw.KeyLeft] = "ArrowLeft"
keyNameMap[glfw.KeyRight] = "ArrowRight"
keyNameMap[glfw.KeyEnd] = "End"
keyNameMap[glfw.KeyDown] = "ArrowDown"
keyNameMap[glfw.KeyInsert] = "Insert"
keyNameMap[glfw.KeyDelete] = "Delete"
// keyNameMap[glfw.KeyApplication] = "ContextMenu"
keyRuneMap[glfw.Key0] = '0'
keyRuneMap[glfw.Key1] = '1'
keyRuneMap[glfw.Key2] = '2'
keyRuneMap[glfw.Key3] = '3'
keyRuneMap[glfw.Key4] = '4'
keyRuneMap[glfw.Key5] = '5'
keyRuneMap[glfw.Key6] = '6'
keyRuneMap[glfw.Key7] = '7'
keyRuneMap[glfw.Key8] = '8'
keyRuneMap[glfw.Key9] = '9'
keyRuneMap[glfw.KeyMinus] = '-'
keyRuneMap[glfw.KeyEqual] = '='
keyRuneMap[glfw.KeyTab] = '\t'
keyRuneMap[glfw.KeyQ] = 'Q'
keyRuneMap[glfw.KeyW] = 'W'
keyRuneMap[glfw.KeyE] = 'E'
keyRuneMap[glfw.KeyR] = 'R'
keyRuneMap[glfw.KeyT] = 'T'
keyRuneMap[glfw.KeyY] = 'Y'
keyRuneMap[glfw.KeyU] = 'U'
keyRuneMap[glfw.KeyI] = 'I'
keyRuneMap[glfw.KeyO] = 'O'
keyRuneMap[glfw.KeyP] = 'P'
keyRuneMap[glfw.KeyLeftBracket] = '['
keyRuneMap[glfw.KeyRightBracket] = ']'
keyRuneMap[glfw.KeyEnter] = '\n'
keyRuneMap[glfw.KeyA] = 'A'
keyRuneMap[glfw.KeyS] = 'S'
keyRuneMap[glfw.KeyD] = 'D'
keyRuneMap[glfw.KeyF] = 'F'
keyRuneMap[glfw.KeyG] = 'G'
keyRuneMap[glfw.KeyH] = 'H'
keyRuneMap[glfw.KeyJ] = 'J'
keyRuneMap[glfw.KeyK] = 'K'
keyRuneMap[glfw.KeyL] = 'L'
keyRuneMap[glfw.KeySemicolon] = ';'
keyRuneMap[glfw.KeyApostrophe] = '\''
keyRuneMap[glfw.KeyGraveAccent] = '`'
keyRuneMap[glfw.KeyBackslash] = '\\'
keyRuneMap[glfw.KeyZ] = 'Z'
keyRuneMap[glfw.KeyX] = 'X'
keyRuneMap[glfw.KeyC] = 'C'
keyRuneMap[glfw.KeyV] = 'V'
keyRuneMap[glfw.KeyB] = 'B'
keyRuneMap[glfw.KeyN] = 'N'
keyRuneMap[glfw.KeyM] = 'M'
keyRuneMap[glfw.KeyComma] = ','
keyRuneMap[glfw.KeyPeriod] = '.'
keyRuneMap[glfw.KeySlash] = '/'
keyRuneMap[glfw.KeyKPMultiply] = '*'
keyRuneMap[glfw.KeySpace] = ' '
keyRuneMap[glfw.KeyKP7] = '7'
keyRuneMap[glfw.KeyKP8] = '8'
keyRuneMap[glfw.KeyKP9] = '9'
keyRuneMap[glfw.KeyKPSubtract] = '-'
keyRuneMap[glfw.KeyKP4] = '4'
keyRuneMap[glfw.KeyKP5] = '5'
keyRuneMap[glfw.KeyKP6] = '6'
keyRuneMap[glfw.KeyKPAdd] = '+'
keyRuneMap[glfw.KeyKP1] = '1'
keyRuneMap[glfw.KeyKP2] = '2'
keyRuneMap[glfw.KeyKP3] = '3'
keyRuneMap[glfw.KeyKP0] = '0'
keyRuneMap[glfw.KeyKPDecimal] = '.'
keyRuneMap[glfw.KeyKPEqual] = '='
keyRuneMap[glfw.KeyKPEnter] = '\n'
keyRuneMap[glfw.KeyKPDivide] = '/'
}
func keyName(key glfw.Key) string {
if int(key) >= len(keyNameMap) {
return "Unidentified"
}
name := keyNameMap[key]
if name == "" {
return "Unidentified"
}
return name
}
func keyRune(key glfw.Key) rune {
if int(key) >= len(keyNameMap) {
return 0
}
return keyRuneMap[key]
}