WIP: Speed up rendering by using a spritesheet

internal/conv/object.go

@@ -3,7 +3,9 @@ package conv
 import (
 	"fmt"
 	"image/color"
+	"image/png"
 	"log"
+	"os"
 
 	"github.com/faiface/pixel"
 
@@ -29,6 +31,89 @@ type Object struct {
 	Sprites []Sprite
 }
 
+func maxWidth(obj *data.Object) int {
+	out := 0
+
+	for _, spr := range obj.Sprites {
+		width := int(spr.Width)
+		if width > out {
+			out = width
+		}
+	}
+
+	return out
+}
+
+func fullHeight(obj *data.Object) int {
+	out := 0
+
+	for _, spr := range obj.Sprites {
+		out = out + int(spr.Height)
+	}
+
+	return out
+}
+
+func ConvertObjects(objects []*data.Object) (map[string]*Object, *pixel.PictureData) {
+	// This needs to be the maxWidth of all the objects, added together
+	maxX := 0
+	for _, obj := range objects {
+		maxX = maxX + maxWidth(obj)
+	}
+
+	// This needs to be the largest fullHeight of all the objects
+	maxY := 0
+	for _, obj := range objects {
+		height := fullHeight(obj)
+		if height > maxY {
+			maxY = height
+		}
+	}
+
+	xOffset := 0
+	spritesheet := pixel.MakePictureData(pixel.R(0.0, 0.0, float64(maxX), float64(maxY)))
+
+	out := make(map[string]*Object)
+	for _, rawObj := range objects {
+		log.Println("xOffset:", xOffset)
+		cObj := ConvertObjectWithSpritesheet(rawObj, rawObj.Name, spritesheet, xOffset)
+		xOffset = xOffset + maxWidth(rawObj)
+		out[cObj.Name] = cObj
+	}
+
+	f, _ := os.Create("spritesheet.png")
+	img := spritesheet.Image()
+	png.Encode(f, img)
+	f.Close()
+
+	return out, spritesheet
+}
+
+func ConvertObjectWithSpritesheet(rawObj *data.Object, name string, pic *pixel.PictureData, xOffset int) *Object {
+	out := &Object{
+		Name:    name,
+		Sprites: make([]Sprite, len(rawObj.Sprites)),
+	}
+
+	// We store the sprites vertically in the provided pic
+	yOffset := 0
+	log.Printf("Converting %v: xOffset = %v", name, xOffset)
+
+	for i, rawSpr := range rawObj.Sprites {
+		spr := spriteToPic(name, i, rawSpr, pic, xOffset, yOffset)
+		log.Printf("	%#v", spr.Frame())
+		out.Sprites[i] = Sprite{
+			Width:  int(rawSpr.Width),
+			Height: int(rawSpr.Height),
+			Pic:    pic,
+			Spr:    spr,
+		}
+		yOffset = yOffset + int(rawSpr.Height)
+	}
+
+	return out
+}
+
 func ConvertObject(rawObj *data.Object, name string) *Object {
 	out := &Object{
 		Name:    name,
@@ -36,37 +121,56 @@ func ConvertObject(rawObj *data.Object, name string) *Object {
 	}
 
 	for i, rawSpr := range rawObj.Sprites {
-		pic := spriteToPic(name, i, rawSpr)
+		pic := pixel.MakePictureData(
+			pixel.R(
+				float64(0),
+				float64(0),
+				float64(rawSpr.Width),
+				float64(rawSpr.Height),
+			),
+		)
+		spr := spriteToPic(name, i, rawSpr, pic, 0, 0)
+
 		out.Sprites[i] = Sprite{
 			Width:  int(rawSpr.Width),
 			Height: int(rawSpr.Height),
 			Pic:    pic,
-			Spr:    pixel.NewSprite(pic, pic.Bounds()),
+			Spr:    spr,
 		}
 	}
 
 	return out
 }
 
-func spriteToPic(name string, idx int, sprite *data.Sprite) *pixel.PictureData {
-	pic := pixel.MakePictureData(pixel.R(float64(0), float64(0), float64(sprite.Width), float64(sprite.Height)))
+func spriteToPic(name string, idx int, sprite *data.Sprite, pic *pixel.PictureData, xOffset, yOffset int) *pixel.Sprite {
 	width := int(sprite.Width)
 	height := int(sprite.Height)
 
-	log.Printf("%v %v: width=%v height=%v", name, idx, width, height)
+	//log.Printf("%v %v: width=%v height=%v", name, idx, width, height)
 
 	for y := 0; y < height; y++ {
 		for x := 0; x < width; x++ {
 			b := sprite.Data[y*width+x]
 
 			// Update the picture
-			if err := setPaletteColor(pic, x, y, b); err != nil {
-				log.Printf("%s %d: %d,%d: %v", name, idx, x, y, err)
+			if err := setPaletteColor(pic, x+xOffset, y+yOffset, b); err != nil {
+				//log.Printf("%s %d: %d,%d: %v", name, idx, x, y, err)
 			}
 		}
 	}
 
-	return pic
+	// FIXME: I really don't get this fetish for starting at the bottom-left
+	bounds := pixel.R(
+		float64(xOffset),
+		float64(yOffset),
+		float64(xOffset+width),
+		float64(yOffset+height),
+	)
+
+	//bounds.Min = bounds.Min.ScaledXY(pixel.Vec{1.0, -1.0})
+	//bounds.Max = bounds.Max.ScaledXY(pixel.Vec{1.0, -1.0})
+
+	return pixel.NewSprite(pic, bounds)
 }
 
 func setPaletteColor(pic *pixel.PictureData, x int, y int, colorIdx byte) error {

internal/data/object.go

@@ -80,6 +80,7 @@ type Object struct {
 	ObjectHeader
 
 	Filename string
+	Name     string // left blank for use by you
 	Sprites  []*Sprite
 }