video

Documentation

Overview

Package video takes care on the game display. It also creates the window using GLFW. It exports the Refresh callback used by the libretro implementation.

Index

• func NewImage(file string) uint32
• func XYWHTo4points(x, y, w, h, fbh float32) (x1, y1, x2, y2, x3, y3, x4, y4 float32)
• type Color
  • func (color Color) Alpha(alpha float32) Color
• type Direction
• type Font
  • func LoadFont(file string, scale int32, windowWidth int, windowHeight int) (*Font, error)
  • func LoadTrueTypeFont(program uint32, r io.Reader, scale int32, low, high rune, dir Direction) (*Font, error)
  • func (f *Font) Printf(x, y float32, scale float32, fs string, argv ...interface{}) error
  • func (f *Font) SetColor(color Color)
  • func (f *Font) UpdateResolution(windowWidth int, windowHeight int)
  • func (f *Font) Width(scale float32, fs string, argv ...interface{}) float32
• type Video
  • func Init(fullscreen bool) *Video
  • func (video *Video) Configure(fullscreen bool)
  • func (video *Video) DrawBorder(x, y, w, h, borderWidth float32, c Color)
  • func (video *Video) DrawCircle(x, y, r float32, c Color)
  • func (video *Video) DrawImage(image uint32, x, y, w, h float32, scale float32, c Color)
  • func (video *Video) DrawRect(x, y, w, h, r float32, c Color)
  • func (video *Video) GetFramebufferSize() (int, int)
  • func (video *Video) Reconfigure(fullscreen bool)
  • func (video *Video) Refresh(data unsafe.Pointer, width int32, height int32, pitch int32)
  • func (video *Video) Render()
  • func (video *Video) ResetPitch()
  • func (video *Video) ResetRot()
  • func (video *Video) ResizeViewport()
  • func (video *Video) ScissorEnd()
  • func (video *Video) ScissorStart(x, y, w, h int32)
  • func (video *Video) SetPixelFormat(format uint32) bool
  • func (video *Video) SetRotation(rot uint) bool
  • func (video *Video) SetShouldClose(b bool)
  • func (video *Video) SetTitle(title string)
  • func (video *Video) TakeScreenshot(name string) error
  • func (video *Video) UpdateFilter(filter string)

Functions

func NewImage

func NewImage(file string) uint32

NewImage opens an image file, upload it the the GPU and returns the texture id

func XYWHTo4points

func XYWHTo4points(x, y, w, h, fbh float32) (x1, y1, x2, y2, x3, y3, x4, y4 float32)

XYWHTo4points converts coordinates from (x, y, width, height) to (x1, y1, x2, y2, x3, y3, x4, y4)

Types

type Color

type Color struct {
	R, G, B, A float32
}

Color is an RGBA type that we use in the menu

func (Color) Alpha

func (color Color) Alpha(alpha float32) Color

Alpha sets the alpha channel of a color

type Direction

type Direction uint8

Direction represents the direction in which strings should be rendered.

const (
	LeftToRight Direction = iota // E.g.: Latin
	RightToLeft                  // E.g.: Arabic
	TopToBottom                  // E.g.: Chinese
)

Known directions.

type Font

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

A Font allows rendering of text to an OpenGL context.

func LoadFont

func LoadFont(file string, scale int32, windowWidth int, windowHeight int) (*Font, error)

LoadFont loads the specified font at the given scale.

func LoadTrueTypeFont

func LoadTrueTypeFont(program uint32, r io.Reader, scale int32, low, high rune, dir Direction) (*Font, error)

LoadTrueTypeFont builds a set of textures based on a ttf files gylphs

func (*Font) Printf

func (f *Font) Printf(x, y float32, scale float32, fs string, argv ...interface{}) error

Printf draws a string to the screen, takes a list of arguments like printf

func (*Font) SetColor

func (f *Font) SetColor(color Color)

SetColor allows you to set the text color to be used when you draw the text

func (*Font) UpdateResolution

func (f *Font) UpdateResolution(windowWidth int, windowHeight int)

UpdateResolution passes the new framebuffer size to the font shader

func (*Font) Width

func (f *Font) Width(scale float32, fs string, argv ...interface{}) float32

Width returns the width of a piece of text in pixels

type Video

type Video struct {
	Window *glfw.Window
	Geom   libretro.GameGeometry
	Font   *Font
	// contains filtered or unexported fields
}

Video holds the state of the video package

func Init

func Init(fullscreen bool) *Video

Init instanciates the video package

func (*Video) Configure

func (video *Video) Configure(fullscreen bool)

Configure instanciates the video package

func (*Video) DrawBorder

func (video *Video) DrawBorder(x, y, w, h, borderWidth float32, c Color)

DrawBorder draws a colored rectangle border

func (*Video) DrawCircle

func (video *Video) DrawCircle(x, y, r float32, c Color)

DrawCircle draws a circle

func (*Video) DrawImage

func (video *Video) DrawImage(image uint32, x, y, w, h float32, scale float32, c Color)

DrawImage draws an image with x, y, w, h

func (*Video) DrawRect

func (video *Video) DrawRect(x, y, w, h, r float32, c Color)

DrawRect draws a rectangle and supports rounded corners

func (*Video) GetFramebufferSize

func (video *Video) GetFramebufferSize() (int, int)

GetFramebufferSize retrieves the size, in pixels, of the framebuffer of the specified window.

func (*Video) Reconfigure

func (video *Video) Reconfigure(fullscreen bool)

Reconfigure destroys and recreates the window with new attributes

func (*Video) Refresh

func (video *Video) Refresh(data unsafe.Pointer, width int32, height int32, pitch int32)

Refresh the texture framebuffer

func (*Video) Render

func (video *Video) Render()

Render the current frame

func (*Video) ResetPitch

func (video *Video) ResetPitch()

ResetPitch should be called when unloading a game so that the next game won't be rendered with the wrong pitch

func (*Video) ResetRot

func (video *Video) ResetRot()

ResetRot should be called when unloading a game so that the next game won't be rendered with the wrong rotation

func (*Video) ResizeViewport

func (video *Video) ResizeViewport()

ResizeViewport resizes the GL viewport to the framebuffer size

func (*Video) ScissorEnd

func (video *Video) ScissorEnd()

ScissorEnd closes a GL scissor box

func (*Video) ScissorStart

func (video *Video) ScissorStart(x, y, w, h int32)

ScissorStart starts a GL scissor box, don't forget to call ScissorEnd

func (*Video) SetPixelFormat

func (video *Video) SetPixelFormat(format uint32) bool

SetPixelFormat is a callback passed to the libretro implementation. It allows the core or the game to tell us which pixel format should be used for the display.

func (*Video) SetRotation

func (video *Video) SetRotation(rot uint) bool

SetRotation rotates the game image as requested by the core

func (*Video) SetShouldClose

func (video *Video) SetShouldClose(b bool)

SetShouldClose sets the value of the close flag of the window.

func (*Video) SetTitle

func (video *Video) SetTitle(title string)

SetTitle sets the window title, encoded as UTF-8, of the window.

func (*Video) TakeScreenshot

func (video *Video) TakeScreenshot(name string) error

TakeScreenshot captures the ouput of video.Render and writes it to a file

func (*Video) UpdateFilter

func (video *Video) UpdateFilter(filter string)

UpdateFilter configures the game texture filter and shader. We currently support 4 modes: Raw: nearest Smooth: linear Pixel Perfect: sharp-bilinear CRT: zfast-crt LCD: zfast-lcd