106 lines
2.1 KiB
Go
106 lines
2.1 KiB
Go
package render
|
|
|
|
import (
|
|
"fmt"
|
|
|
|
"git.kirsle.net/apps/doodle/events"
|
|
)
|
|
|
|
// Engine is the interface for the rendering engine, keeping SDL-specific stuff
|
|
// far away from the core of Doodle.
|
|
type Engine interface {
|
|
Setup() error
|
|
|
|
// Poll for events like keypresses and mouse clicks.
|
|
Poll() (*events.State, error)
|
|
GetTicks() uint32
|
|
|
|
// Present presents the current state to the screen.
|
|
Present() error
|
|
|
|
// Clear the full canvas and set this color.
|
|
Clear(Color)
|
|
DrawPoint(Color, Point)
|
|
DrawLine(Color, Point, Point)
|
|
DrawRect(Color, Rect)
|
|
DrawBox(Color, Rect)
|
|
DrawText(Text, Point) error
|
|
|
|
// Delay for a moment using the render engine's delay method,
|
|
// implemented by sdl.Delay(uint32)
|
|
Delay(uint32)
|
|
|
|
// Tasks that the Setup function should defer until tear-down.
|
|
Teardown()
|
|
|
|
Loop() error // maybe?
|
|
}
|
|
|
|
// Color holds an RGBA color value.
|
|
type Color struct {
|
|
Red uint8
|
|
Green uint8
|
|
Blue uint8
|
|
Alpha uint8
|
|
}
|
|
|
|
func (c Color) String() string {
|
|
return fmt.Sprintf(
|
|
"Color<#%02x%02x%02x>",
|
|
c.Red, c.Green, c.Blue,
|
|
)
|
|
}
|
|
|
|
// Point holds an X,Y coordinate value.
|
|
type Point struct {
|
|
X int32
|
|
Y int32
|
|
}
|
|
|
|
func (p Point) String() string {
|
|
return fmt.Sprintf("Point<%d,%d>", p.X, p.Y)
|
|
}
|
|
|
|
// Rect has a coordinate and a width and height.
|
|
type Rect struct {
|
|
X int32
|
|
Y int32
|
|
W int32
|
|
H int32
|
|
}
|
|
|
|
func (r Rect) String() string {
|
|
return fmt.Sprintf("Rect<%d,%d,%d,%d>",
|
|
r.X, r.Y, r.W, r.H,
|
|
)
|
|
}
|
|
|
|
// Text holds information for drawing text.
|
|
type Text struct {
|
|
Text string
|
|
Size int
|
|
Color Color
|
|
Stroke Color // Stroke color (if not zero)
|
|
Shadow Color // Drop shadow color (if not zero)
|
|
}
|
|
|
|
func (t Text) String() string {
|
|
return fmt.Sprintf("Text<%s>", t.Text)
|
|
}
|
|
|
|
// Common color names.
|
|
var (
|
|
Invisible = Color{}
|
|
White = Color{255, 255, 255, 255}
|
|
Grey = Color{153, 153, 153, 255}
|
|
Black = Color{0, 0, 0, 255}
|
|
SkyBlue = Color{0, 153, 255, 255}
|
|
Blue = Color{0, 0, 255, 255}
|
|
Red = Color{255, 0, 0, 255}
|
|
Green = Color{0, 255, 0, 255}
|
|
Cyan = Color{0, 255, 255, 255}
|
|
Yellow = Color{255, 255, 0, 255}
|
|
Magenta = Color{255, 0, 255, 255}
|
|
Pink = Color{255, 153, 255, 255}
|
|
)
|