sdl_output

package
v0.0.0-...-09ec4ce Latest Latest
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 Go to latest Published: Dec 15, 2023 License: MIT Imports: 19 Imported by: 0

Documentation

Overview

GoSpeccy SDL interface (audio&video output, keyboard input)

Index

Constants

View Source 
const (
	HIDE = iota
	SHOW
)
View Source 
const BUFSIZE_IDEAL = 3

Ideal number of buffered 'AudioData' objects, in order to prevent [SDL buffer underruns] and [Go channel overruns].

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const DEFAULT_JOYSTICK_ID = 0
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const FREQUENCY_CHANGE_RATE = 1.0002
View Source 
const MIN_PLAYBACK_FREQUENCY = 10000

The function 'bufferRemove' requires a sufficiently high frequency so that FREQUENCY_CHANGE_RATE has an actual impact on the frequency. In other words: ((FREQUENCY_CHANGE_RATE-1) * MIN_PLAYBACK_FREQUENCY) has to be greater than 1.

View Source 
const PLAYBACK_FREQUENCY = 48000

The default SDL-audio playback frequency

View Source 
const RESPONSE_FREQUENCY = 12000

The ZX Spectrum beeper has only two levels: 0 and 1. However, the beeper can produce multi-channel sound if it changes so quickly that the speaker (speaker = the physical object that the TV uses to produce the sound) is unable to keep up with the rate of changes between the levels. This effectively puts the speaker into a position somewhere *between* 0 and 1 (e.g: 0.25, 0.7)

The RESPONSE_FREQUENCY is a frequency at which the multi-channel music in certain ZX Spectrum games and demos sounds "good-enough" to the human ear.

It is used only when 'hqAudio' is enabled.

Variables

View Source 
var (
	Scale2x            = flag.Bool("2x", false, "2x display scaler")
	Fullscreen         = flag.Bool("fullscreen", false, "Fullscreen (enable 2x scaler by default)")
	Audio              = flag.Bool("audio", true, "Enable or disable audio")
	AudioFreq          = flag.Uint("audio-freq", PLAYBACK_FREQUENCY, "Audio playback frequency (units: Hz)")
	HQAudio            = flag.Bool("audio-hq", true, "Enable or disable higher-quality audio")
	ShowPaintedRegions = flag.Bool("show-paint", false, "Show painted display regions")
)

Functions

func Main 

func Main()

func SDL_updateRects 

func SDL_updateRects(surface *sdl.Surface, surfaceChanges *ListOfRects, scale uint, updatedRectsCh chan []sdl.Rect)

Types

type InitialSettings 

type InitialSettings struct {
	// contains filtered or unexported fields
}

func (*InitialSettings) EnableAudio 

func (s *InitialSettings) EnableAudio(enable bool)

func (*InitialSettings) ResizeVideo 

func (s *InitialSettings) ResizeVideo(scale2x, fullscreen bool)

func (*InitialSettings) SetAudioFreq 

func (s *InitialSettings) SetAudioFreq(freq uint)

func (*InitialSettings) SetAudioQuality 

func (s *InitialSettings) SetAudioQuality(hqAudio bool)

func (*InitialSettings) ShowPaintedRegions 

func (s *InitialSettings) ShowPaintedRegions(enable bool)

func (*InitialSettings) Terminated 

func (s *InitialSettings) Terminated() bool

type ListOfRects 

type ListOfRects []sdl.Rect

type SDLAudio 

type SDLAudio struct {
	// contains filtered or unexported fields
}

func NewSDLAudio 

func NewSDLAudio(app *spectrum.Application, playbackFrequency uint, hqAudio bool) (*SDLAudio, error)

Opens SDL audio. If 'playbackFrequency' is 0, the frequency will be equivalent to PLAYBACK_FREQUENCY.

func (*SDLAudio) Close 

func (audio *SDLAudio) Close()

func (*SDLAudio) GetAudioDataChannel 

func (audio *SDLAudio) GetAudioDataChannel() chan<- *spectrum.AudioData

Implement AudioReceiver

type SDLRenderer 

type SDLRenderer struct {
	// contains filtered or unexported fields
}

func NewSDLRenderer 

func NewSDLRenderer(app *spectrum.Application, speccy *spectrum.Spectrum48k, scale2x, fullscreen bool, audio, hqAudio bool, audioFreq uint) *SDLRenderer

func (*SDLRenderer) EnableAudio 

func (r *SDLRenderer) EnableAudio(enable bool)

func (*SDLRenderer) ResizeVideo 

func (r *SDLRenderer) ResizeVideo(scale2x, fullscreen bool)

func (*SDLRenderer) SetAudioFreq 

func (r *SDLRenderer) SetAudioFreq(freq uint)

func (*SDLRenderer) SetAudioQuality 

func (r *SDLRenderer) SetAudioQuality(hqAudio bool)

func (*SDLRenderer) ShowPaintedRegions 

func (r *SDLRenderer) ShowPaintedRegions(enable bool)

func (*SDLRenderer) Terminated 

func (r *SDLRenderer) Terminated() bool

type SDLScreen 

type SDLScreen struct {
	// contains filtered or unexported fields
}

func NewSDLScreen 

func NewSDLScreen(app *spectrum.Application) *SDLScreen

func (*SDLScreen) Close 

func (display *SDLScreen) Close()

func (*SDLScreen) GetDisplayDataChannel 

func (display *SDLScreen) GetDisplayDataChannel() chan<- *spectrum.DisplayData

Implement DisplayReceiver

func (*SDLScreen) GetSurface 

func (display *SDLScreen) GetSurface() *sdl.Surface

func (*SDLScreen) UpdatedRectsCh 

func (display *SDLScreen) UpdatedRectsCh() <-chan []sdl.Rect

type SDLScreen2x 

type SDLScreen2x struct {
	// contains filtered or unexported fields
}

func NewSDLScreen2x 

func NewSDLScreen2x(app *spectrum.Application) *SDLScreen2x

func (*SDLScreen2x) Close 

func (display *SDLScreen2x) Close()

func (*SDLScreen2x) GetDisplayDataChannel 

func (display *SDLScreen2x) GetDisplayDataChannel() chan<- *spectrum.DisplayData

Implement DisplayReceiver

func (*SDLScreen2x) GetSurface 

func (display *SDLScreen2x) GetSurface() *sdl.Surface

func (*SDLScreen2x) UpdatedRectsCh 

func (display *SDLScreen2x) UpdatedRectsCh() <-chan []sdl.Rect

type SDLSurface 

type SDLSurface struct {
	// contains filtered or unexported fields
}

func NewSDLSurface 

func NewSDLSurface(app *spectrum.Application) *SDLSurface

Create an SDL surface suitable for an unscaled screen

func NewSDLSurface2x 

func NewSDLSurface2x(app *spectrum.Application) *SDLSurface

Create an SDL surface suitable for a 2x scaled screen

func (SDLSurface) Bpp 

func (s SDLSurface) Bpp() uint

func (SDLSurface) Height 

func (s SDLSurface) Height() uint

func (SDLSurface) Pitch 

func (s SDLSurface) Pitch() uint

func (SDLSurface) Width 

func (s SDLSurface) Width() uint

type SDLSurfaceAccessor 

type SDLSurfaceAccessor interface {
	UpdatedRectsCh() <-chan []sdl.Rect
	GetSurface() *sdl.Surface
}

type SDLSurfaceComposer 

type SDLSurfaceComposer struct {
	// contains filtered or unexported fields
}

Composes multiple SDL surfaces into a single surface

func NewSDLSurfaceComposer 

func NewSDLSurfaceComposer(app *spectrum.Application) *SDLSurfaceComposer

Creates a new composer, and starts its command-loop in a goroutine

func (*SDLSurfaceComposer) AddInputSurface 

func (composer *SDLSurfaceComposer) AddInputSurface(surface *sdl.Surface, x, y int, updatedRectsCh <-chan []sdl.Rect)

Enqueues a command that will append the specified surface to the end of [the list of input surfaces of 'composer'].

The order of surfaces in the mentioned list defines the compositing order. The first surface will visually appear at the bottom, while the last surface will visually appear at the top.

func (*SDLSurfaceComposer) RemoveAllInputSurfaces 

func (composer *SDLSurfaceComposer) RemoveAllInputSurfaces() <-chan byte

Enqueues a command that will clear [the list of input surfaces of 'composer']. The returned channel will receive a single value when the command completes.

func (*SDLSurfaceComposer) RemoveInputSurface 

func (composer *SDLSurfaceComposer) RemoveInputSurface(surface *sdl.Surface) <-chan byte

Enqueues a command that will remove the specified surface from [the list of input surfaces of 'composer']. The returned channel will receive a single value when the command completes.

func (*SDLSurfaceComposer) ReplaceOutputSurface 

func (composer *SDLSurfaceComposer) ReplaceOutputSurface(surface_orNil *sdl.Surface) <-chan byte

Enqueues a command that will replace the output surface. The returned channel will receive a single value when the command completes.

func (*SDLSurfaceComposer) SetPosition 

func (composer *SDLSurfaceComposer) SetPosition(surface *sdl.Surface, x, y int)

Enqueues a command that will move the specified surface to a new position

func (*SDLSurfaceComposer) ShowPaintedRegions 

func (composer *SDLSurfaceComposer) ShowPaintedRegions(enable bool)

Enqueues a command that will set the "show painted regions" flag. If the flag is set to true, then each paint operation is covered by a semi-transparent randomly colored rectangle.

type UnscaledDisplay 

type UnscaledDisplay struct {
	// contains filtered or unexported fields
}

Source Files

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