From 2c2e20404e80569fe1fce8cb105b62c9e5e97f0d Mon Sep 17 00:00:00 2001
From: NatureFreshMilk <naturefreshmilk@github.com>
Date: Fri, 11 Jan 2019 13:30:51 +0100
Subject: [PATCH] working renderer

---
 mapblockrenderer/renderer.go      | 89 ++++++++++++++++++++++++++++---
 mapblockrenderer/renderer_test.go |  7 ++-
 2 files changed, 89 insertions(+), 7 deletions(-)

diff --git a/mapblockrenderer/renderer.go b/mapblockrenderer/renderer.go
index 1e30971..2863f8a 100644
--- a/mapblockrenderer/renderer.go
+++ b/mapblockrenderer/renderer.go
@@ -5,7 +5,9 @@ import (
 	"mapserver/coords"
 	"mapserver/mapblockaccessor"
 	"image"
-	"image/color"
+	"image/draw"
+	"errors"
+	"fmt"
 )
 
 type MapBlockRenderer struct {
@@ -20,14 +22,89 @@ func NewMapBlockRenderer(accessor *mapblockaccessor.MapBlockAccessor, colors *co
 const (
 	IMG_SCALE = 16
 	IMG_SIZE = IMG_SCALE * 16
+	EXPECTED_BLOCKS_PER_FLAT_MAPBLOCK = 16*16
 )
 
-func (r *MapBlockRenderer) Render(pos1, pos2 coords.MapBlockCoords) *image.RGBA {
+func (r *MapBlockRenderer) Render(pos1, pos2 coords.MapBlockCoords) (*image.NRGBA, error) {
+	if pos1.X != pos2.X {
+		return nil, errors.New("X does not line up")
+	}
+
+	if pos1.Z != pos2.Z {
+		return nil, errors.New("Z does not line up")
+	}
+
 	upLeft := image.Point{0, 0}
 	lowRight := image.Point{IMG_SIZE, IMG_SIZE}
+	img := image.NewNRGBA(image.Rectangle{upLeft, lowRight})
 
-	img := image.NewRGBA(image.Rectangle{upLeft, lowRight})
-	cyan := color.RGBA{100, 200, 200, 0xff}
-	img.Set(10, 10, cyan)
-	return img
+	maxY := pos1.Y
+	minY := pos2.Y
+
+	if minY > maxY {
+		maxY, minY = minY, maxY
+	}
+
+	foundBlocks := 0
+	xzOccupationMap := make([][]bool, 16)
+	for x := range xzOccupationMap {
+		xzOccupationMap[x] = make([]bool, 16)
+	}
+
+	for mapBlockY := maxY; mapBlockY >= minY; mapBlockY-- {
+		currentPos := coords.NewMapBlockCoords(pos1.X, mapBlockY, pos1.Z)
+		mb, err := r.accessor.GetMapBlock(currentPos)
+
+		if err != nil {
+			return nil, err
+		}
+
+		if mb == nil {
+			continue
+		}
+
+		for x := 0; x < 16; x++ {
+			for z := 0; z < 16; z++ {
+				for y := 15; y >= 0; y-- {
+					if xzOccupationMap[x][z] {
+						continue
+					}
+
+					nodeName := mb.GetNodeName(x,y,z)
+
+					fmt.Println(x,y,z, nodeName)//XXX
+					if nodeName == "" {
+						continue
+					}
+
+					c := r.colors.GetColor(nodeName)
+
+					if c == nil {
+						continue
+					}
+
+					rect := image.Rect(
+						x*IMG_SCALE, z*IMG_SCALE,
+						(x*IMG_SCALE)+IMG_SCALE, (z*IMG_SCALE)+IMG_SCALE,
+					)
+
+					foundBlocks++
+					xzOccupationMap[x][z] = true
+					draw.Draw(img, rect, &image.Uniform{c}, image.ZP, draw.Src)
+
+					if foundBlocks == EXPECTED_BLOCKS_PER_FLAT_MAPBLOCK {
+						break
+					}
+				}
+				if foundBlocks == EXPECTED_BLOCKS_PER_FLAT_MAPBLOCK {
+					break
+				}
+			}
+		}
+		if foundBlocks == EXPECTED_BLOCKS_PER_FLAT_MAPBLOCK {
+			break
+		}
+	}
+
+	return img, nil
 }
diff --git a/mapblockrenderer/renderer_test.go b/mapblockrenderer/renderer_test.go
index f2a505e..2fa8bf2 100644
--- a/mapblockrenderer/renderer_test.go
+++ b/mapblockrenderer/renderer_test.go
@@ -32,10 +32,15 @@ func TestSimpleRender(t *testing.T) {
 
   cache := mapblockaccessor.NewMapBlockAccessor(a)
   c := colormapping.NewColorMapping()
+  err = c.LoadVFSColors(false, "/colors.txt")
+  if err != nil {
+    t.Fatal(err)
+  }
 
   r := NewMapBlockRenderer(cache, c)
-  img := r.Render(coords.NewMapBlockCoords(0, 10, 0), coords.NewMapBlockCoords(0, -1, 0))
+  img, _ := r.Render(coords.NewMapBlockCoords(0, 10, 0), coords.NewMapBlockCoords(0, -1, 0))
 
   f, _ := os.Create("image.png")
   png.Encode(f, img)
+  f.Close()
 }