doodle/pkg/level/chunk.go
Noah Petherbridge 2b42a072a0 Code Layout Refactor
* All private Doodle source code into the pkg/ folder.
* Potentially public code into the lib/ folder.
* Centralize the logger into a subpackage.
2019-04-09 17:35:44 -07:00

278 lines
6.4 KiB
Go

package level
import (
"encoding/json"
"fmt"
"image"
"math"
"os"
"git.kirsle.net/apps/doodle/lib/render"
"git.kirsle.net/apps/doodle/pkg/balance"
"git.kirsle.net/apps/doodle/pkg/log"
"git.kirsle.net/apps/doodle/pkg/userdir"
"github.com/satori/go.uuid"
"golang.org/x/image/bmp"
)
// Types of chunks.
const (
MapType int = iota
GridType
)
// Chunk holds a single portion of the pixel canvas.
type Chunk struct {
Type int // map vs. 2D array.
Accessor
// Values told to it from higher up, not stored in JSON.
Point render.Point
Size int
// Texture cache properties so we don't redraw pixel-by-pixel every frame.
uuid uuid.UUID
texture render.Texturer
textureMasked render.Texturer
dirty bool
}
// JSONChunk holds a lightweight (interface-free) copy of the Chunk for
// unmarshalling JSON files from disk.
type JSONChunk struct {
Type int `json:"type"`
Data json.RawMessage `json:"data"`
}
// Accessor provides a high-level API to interact with absolute pixel coordinates
// while abstracting away the details of how they're stored.
type Accessor interface {
Inflate(*Palette) error
Iter() <-chan Pixel
IterViewport(viewport render.Rect) <-chan Pixel
Get(render.Point) (*Swatch, error)
Set(render.Point, *Swatch) error
Delete(render.Point) error
Len() int
MarshalJSON() ([]byte, error)
UnmarshalJSON([]byte) error
}
// NewChunk creates a new chunk.
func NewChunk() *Chunk {
return &Chunk{
Type: MapType,
Accessor: NewMapAccessor(),
}
}
// Texture will return a cached texture for the rendering engine for this
// chunk's pixel data. If the cache is dirty it will be rebuilt in this func.
func (c *Chunk) Texture(e render.Engine) render.Texturer {
if c.texture == nil || c.dirty {
// Generate the normal bitmap and one with a color mask if applicable.
bitmap := c.toBitmap(render.Invisible)
defer os.Remove(bitmap)
tex, err := e.NewBitmap(bitmap)
if err != nil {
log.Error("Texture: %s", err)
}
c.texture = tex
c.textureMasked = nil // invalidate until next call
c.dirty = false
}
return c.texture
}
// TextureMasked returns a cached texture with the ColorMask applied.
func (c *Chunk) TextureMasked(e render.Engine, mask render.Color) render.Texturer {
if c.textureMasked == nil {
// Generate the normal bitmap and one with a color mask if applicable.
bitmap := c.toBitmap(mask)
defer os.Remove(bitmap)
tex, err := e.NewBitmap(bitmap)
if err != nil {
log.Error("Texture: %s", err)
}
c.textureMasked = tex
}
return c.textureMasked
}
// toBitmap puts the texture in a well named bitmap path in the cache folder.
func (c *Chunk) toBitmap(mask render.Color) string {
// Generate a unique filename for this chunk cache.
var filename string
if c.uuid == uuid.Nil {
c.uuid = uuid.Must(uuid.NewV4())
}
filename = c.uuid.String()
if mask != render.Invisible {
filename += fmt.Sprintf("-%02x%02x%02x%02x",
mask.Red, mask.Green, mask.Blue, mask.Alpha,
)
}
// Get the temp bitmap image.
bitmap := userdir.CacheFilename("chunk", filename+".bmp")
err := c.ToBitmap(bitmap, mask)
if err != nil {
log.Error("Texture: %s", err)
}
return bitmap
}
// ToBitmap exports the chunk's pixels as a bitmap image.
func (c *Chunk) ToBitmap(filename string, mask render.Color) error {
canvas := c.SizePositive()
imgSize := image.Rectangle{
Min: image.Point{},
Max: image.Point{
X: c.Size,
Y: c.Size,
},
}
if imgSize.Max.X == 0 {
imgSize.Max.X = int(canvas.W)
}
if imgSize.Max.Y == 0 {
imgSize.Max.Y = int(canvas.H)
}
img := image.NewRGBA(imgSize)
// Blank out the pixels.
for x := 0; x < img.Bounds().Max.X; x++ {
for y := 0; y < img.Bounds().Max.Y; y++ {
img.Set(x, y, balance.DebugChunkBitmapBackground.ToColor())
}
}
// Pixel coordinate offset to map the Chunk World Position to the
// smaller image boundaries.
pointOffset := render.Point{
X: int32(c.Point.X * int32(c.Size)),
Y: int32(c.Point.Y * int32(c.Size)),
}
// Blot all the pixels onto it.
for px := range c.Iter() {
var color = px.Swatch.Color
if mask != render.Invisible {
color = mask
}
img.Set(
int(px.X-pointOffset.X),
int(px.Y-pointOffset.Y),
color.ToColor(),
)
}
fh, err := os.Create(filename)
if err != nil {
return err
}
defer fh.Close()
return bmp.Encode(fh, img)
}
// Set proxies to the accessor and flags the texture as dirty.
func (c *Chunk) Set(p render.Point, sw *Swatch) error {
c.dirty = true
return c.Accessor.Set(p, sw)
}
// Delete proxies to the accessor and flags the texture as dirty.
func (c *Chunk) Delete(p render.Point) error {
c.dirty = true
return c.Accessor.Delete(p)
}
// Rect returns the bounding coordinates that the Chunk has pixels for.
func (c *Chunk) Rect() render.Rect {
// Lowest and highest chunks.
var (
lowest render.Point
highest render.Point
)
for coord := range c.Iter() {
if coord.X < lowest.X {
lowest.X = coord.X
}
if coord.Y < lowest.Y {
lowest.Y = coord.Y
}
if coord.X > highest.X {
highest.X = coord.X
}
if coord.Y > highest.Y {
highest.Y = coord.Y
}
}
return render.Rect{
X: lowest.X,
Y: lowest.Y,
W: highest.X,
H: highest.Y,
}
}
// SizePositive returns the Size anchored to 0,0 with only positive
// coordinates.
func (c *Chunk) SizePositive() render.Rect {
S := c.Rect()
return render.Rect{
W: int32(math.Abs(float64(S.X))) + S.W,
H: int32(math.Abs(float64(S.Y))) + S.H,
}
}
// Usage returns the percent of free space vs. allocated pixels in the chunk.
func (c *Chunk) Usage(size int) float64 {
return float64(c.Len()) / float64(size)
}
// MarshalJSON writes the chunk to JSON.
func (c *Chunk) MarshalJSON() ([]byte, error) {
data, err := c.Accessor.MarshalJSON()
if err != nil {
return []byte{}, err
}
generic := &JSONChunk{
Type: c.Type,
Data: data,
}
b, err := json.Marshal(generic)
return b, err
}
// UnmarshalJSON loads the chunk from JSON and uses the correct accessor to
// parse the inner details.
func (c *Chunk) UnmarshalJSON(b []byte) error {
// Parse it generically so we can hand off the inner "data" object to the
// right accessor for unmarshalling.
generic := &JSONChunk{}
err := json.Unmarshal(b, generic)
if err != nil {
return fmt.Errorf("Chunk.UnmarshalJSON: failed to unmarshal into generic JSONChunk type: %s", err)
}
switch c.Type {
case MapType:
c.Accessor = NewMapAccessor()
return c.Accessor.UnmarshalJSON(generic.Data)
default:
return fmt.Errorf("Chunk.UnmarshalJSON: unsupported chunk type '%d'", c.Type)
}
}