mtsatellite/common/renderer.go

532 lines
11 KiB
Go

// Copyright 2014 by Sascha L. Teichmann
// Use of this source code is governed by the MIT license
// that can be found in the LICENSE file.
package common
import (
"container/heap"
"image"
"image/color"
"math"
)
type Area struct {
X1, Z1 int16
X2, Z2 int16
}
type Renderer struct {
width int
height int
xOfs int16
zOfs int16
yBuffer []int32
yMin []int32
cBuffer []int32
RejectedBlocks int
SolidBlocks int
TransparentBlocks int
spans *SpanPool
tBuffer []*Span
}
type YOrder struct {
Renderer *Renderer
blocks []*Block
capacity int
}
func NewYOrder(renderer *Renderer, capacity int) *YOrder {
return &YOrder{
Renderer: renderer,
blocks: make([]*Block, 0, capacity),
capacity: capacity}
}
func (yo *YOrder) Reset() {
yo.blocks = yo.blocks[0:0]
}
func max(a, b int) int {
if a > b {
return a
}
return b
}
func max32(a, b int32) int32 {
if a > b {
return a
}
return b
}
func copyData(data []byte) []byte {
l := len(data)
ndata := make([]byte, l, max(l, 8*1024))
copy(ndata, data)
return ndata
}
func (yo *YOrder) RenderBlock(block *Block, colors *Colors) (err error) {
var nblock *Block
if len(yo.blocks) == yo.capacity {
oblock := yo.blocks[0]
if oblock.Coord.Y < block.Coord.Y {
// New one is above highest old. Directly render new.
err = yo.Renderer.RenderBlock(block, colors)
return
}
// Render old one. Store copy of new in heap.
heap.Pop(yo)
err = yo.Renderer.RenderBlock(oblock, colors)
l := len(block.Data)
if cap(oblock.Data) < l {
oblock.Data = make([]byte, l, max(l, 8*1024))
} else {
oblock.Data = oblock.Data[0:l]
}
copy(oblock.Data, block.Data)
oblock.Coord = block.Coord
nblock = oblock
} else {
nblock = &Block{Coord: block.Coord, Data: copyData(block.Data)}
}
heap.Push(yo, nblock)
return
}
func (yo *YOrder) Drain(colors *Colors) (err error) {
for len(yo.blocks) > 0 {
if err = yo.Renderer.RenderBlock(heap.Pop(yo).(*Block), colors); err != nil {
return
}
}
return
}
func (yo *YOrder) Len() int {
return len(yo.blocks)
}
func (yo *YOrder) Swap(i, j int) {
yo.blocks[i], yo.blocks[j] = yo.blocks[j], yo.blocks[i]
}
func (yo *YOrder) Less(i, j int) bool {
// Reverse order intented.
return yo.blocks[i].Coord.Y > yo.blocks[j].Coord.Y
}
func (yo *YOrder) Push(x interface{}) {
yo.blocks = append(yo.blocks, x.(*Block))
}
func (yo *YOrder) Pop() (x interface{}) {
l := len(yo.blocks)
x = yo.blocks[l-1]
yo.blocks = yo.blocks[0 : l-1]
return x
}
func NewRenderer(width, height int, transparent bool) (renderer *Renderer) {
dim := width * height
pixSize := dim * 16 * 16
yBuffer := make([]int32, pixSize)
cBuffer := make([]int32, pixSize)
yMin := make([]int32, dim)
var tBuffer []*Span
var spans *SpanPool
if transparent {
tBuffer = make([]*Span, pixSize)
spans = NewSpanPool()
}
renderer = &Renderer{
width: width,
height: height,
yBuffer: yBuffer,
cBuffer: cBuffer,
yMin: yMin,
tBuffer: tBuffer,
spans: spans}
renderer.Reset()
return
}
func (r *Renderer) SetPos(xOfs, zOfs int16) {
r.xOfs = xOfs
r.zOfs = zOfs
}
func (r *Renderer) Reset() {
for i, n := 0, len(r.yBuffer); i < n; i++ {
r.yBuffer[i] = math.MinInt32
r.cBuffer[i] = -1
}
for i, n := 0, len(r.yMin); i < n; i++ {
r.yMin[i] = math.MinInt32
}
if r.TransparentBlocks > 0 {
r.TransparentBlocks = 0
for i, t := range r.tBuffer {
if t != nil {
r.spans.FreeAll(t)
r.tBuffer[i] = nil
}
}
}
r.SolidBlocks = 0
r.RejectedBlocks = 0
}
func (r *Renderer) IsFilled() bool {
for _, y := range r.yMin {
if y == math.MinInt32 {
return false
}
}
return true
}
func (r *Renderer) RenderBlock(block *Block, colors *Colors) (err error) {
bx := block.Coord.X - r.xOfs
bz := block.Coord.Z - r.zOfs
// We do not need to render the block if the whole 16x16 area
// is already filled and the block is strictly below.
blockY := int32(block.Coord.Y) << 4
pos := int(bz)*r.width + int(bx)
if blockY < r.yMin[pos] {
r.RejectedBlocks++
return
}
// Decoding is pretty expensive so do it that late.
var db *DecodedBlock
if db, err = NewDecodedBlock(block.Data, colors); err != nil {
return
}
if db.AirOnly() {
r.RejectedBlocks++
return
}
w := r.width << 4
ofs := int(bz)*w<<4 + int(bx)<<4
yB := r.yBuffer
yMin := int32(math.MaxInt32)
if db.Transparent && r.tBuffer != nil {
r.TransparentBlocks++
for z := 0; z < 16; z++ {
for x := 0; x < 16; x++ {
currentY := yB[ofs]
if currentY < blockY {
for y := 15; y >= 0; y-- {
if c, ok := db.Content(x, y, z); ok {
cY := blockY + int32(y)
if colors.IsTransparent(c) {
r.tBuffer[ofs] = r.spans.Insert(r.tBuffer[ofs], cY, c)
} else {
r.cBuffer[ofs] = c
currentY = cY
yB[ofs] = currentY
break
}
}
}
}
if currentY < yMin {
yMin = currentY
}
ofs++
}
ofs += w - 16
}
} else {
r.SolidBlocks++
for z := 0; z < 16; z++ {
for x := 0; x < 16; x++ {
currentY := yB[ofs]
if currentY < blockY {
for y := 15; y >= 0; y-- {
if c, ok := db.Content(x, y, z); ok {
r.cBuffer[ofs] = c
currentY = blockY + int32(y)
yB[ofs] = currentY
break
}
}
}
if currentY < yMin {
yMin = currentY
}
ofs++
}
ofs += w - 16
}
}
r.yMin[pos] = yMin
return
}
func (a Area) Contains(x, z int16) bool {
return x >= a.X1 && x <= a.X2 && z >= a.Z1 && z <= a.Z2
}
func (a Area) IsHigher() bool {
return a.Z2-a.Z1 > a.X2-a.X1
}
func areasContain(areas []Area, x, z int16) bool {
for _, r := range areas {
if r.Contains(x, z) {
return true
}
}
return false
}
// Greedy algorithm to figure out a list of disjunct areas
// of free regions in the domain to the (x, z) block plane.
// oldAreas are searched and found free areas are appended
// to newAreas which ist return.
// This is useful to spatial query only blocks from db
// that are not below already rendered blocks.
func (r *Renderer) UncoveredAreas(newAreas, oldAreas []Area) []Area {
yM := r.yMin
// Scan old areas.
for _, oldArea := range oldAreas {
for z := oldArea.Z1; z <= oldArea.Z2; z++ {
row := z * int16(r.width)
for x := oldArea.X1; x <= oldArea.X2; x++ {
// Uncovered and not in list of new areas?
if yM[row+x] > math.MinInt32 || areasContain(newAreas, x, z) {
continue
}
area := Area{X1: x, Z1: z, X2: x, Z2: z}
// Try to extend the area in x and/or z till no further extension is possible.
for extendDirs := 1 | 2; extendDirs != 0; {
var xFirst bool
// Try to extend in the direction with most gain
// of blocks.
if area.IsHigher() { // Higher means to win more blocks in x direction.
xFirst = true
}
dirs:
for i := 0; i < 2; i++ {
if xFirst {
// Extension in x possible?
if extendDirs&1 == 1 {
nx := area.X2 + 1
if nx >= int16(r.width) {
extendDirs &= ^1
continue
}
// Scan line below current area if its fully free.
for nz := area.Z1; nz <= area.Z2; nz++ {
if yM[nz*int16(r.width)+nx] > math.MinInt32 || areasContain(newAreas, nx, nz) {
extendDirs &= ^1
continue dirs
}
}
// free -> extend
area.X2 = nx
}
} else if extendDirs&2 == 2 {
// Symmetric case in z direction
nz := area.Z2 + 1
if nz >= int16(r.height) {
extendDirs &= ^2
continue
}
// Scan line right beside the area if its free.
row2 := nz * int16(r.width)
for nx := area.X1; nx <= area.X2; nx++ {
if yM[row2+nx] > math.MinInt32 || areasContain(newAreas, nx, nz) {
extendDirs &= ^2
continue dirs
}
}
area.Z2 = nz
}
// Switch to other search direction (x -> z or z -> x)
xFirst = !xFirst
}
}
// At this point the area is extended to max.
newAreas = append(newAreas, area)
}
}
}
return newAreas
}
func (r *Renderer) CreateImage(colors []color.RGBA, background color.RGBA) *image.RGBA {
pw, ph := r.width<<4, r.height<<4
image := image.NewRGBA(image.Rect(0, 0, pw, ph))
ofs, numCols := 0, int32(len(colors))
for z := ph - 1; z >= 0; z-- {
for x := 0; x < pw; x++ {
colIdx := r.cBuffer[ofs]
if colIdx >= 0 && colIdx < numCols {
image.Set(x, z, colors[colIdx])
} else {
image.Set(x, z, background)
}
ofs++
}
}
return image
}
func safeColor(x int32) uint8 {
switch {
case x < 0:
return 0
case x > 255:
return 255
default:
return uint8(x)
}
}
func (r *Renderer) CreateShadedImage(
xOfs, zOfs, width, height int,
cols *Colors, background color.RGBA) *image.RGBA {
image := image.NewRGBA(image.Rect(0, 0, width, height))
pw := r.width << 4
cs := cols.Colors
ofs, numCols := zOfs*pw+xOfs, int32(len(cs))
stride := pw - width
istride := image.Stride + 4*width
iofs := image.PixOffset(0, height-1)
pix := image.Pix
if r.TransparentBlocks > 0 { // Fast path for transparent images.
for z := height - 1; z >= 0; z-- {
for x := 0; x < width; x++ {
colIdx := r.cBuffer[ofs]
if colIdx < 0 || colIdx >= numCols {
pix[iofs] = background.R
pix[iofs+1] = background.G
pix[iofs+2] = background.B
pix[iofs+3] = 0xff
} else {
y := r.yBuffer[ofs]
t := r.tBuffer[ofs]
opaque := t == nil || t.Top() < y
var y1, y2 int32
if x == 0 {
y1 = y
} else {
y1 = r.yBuffer[ofs-1]
if opaque {
if s := r.tBuffer[ofs-1]; s != nil {
y1 = max32(y1, s.Top())
}
}
}
if z == 0 {
y2 = y
} else {
y2 = r.yBuffer[ofs+pw]
if opaque {
if s := r.tBuffer[ofs+pw]; s != nil {
y1 = max32(y1, s.Top())
}
}
}
d := ((y - y1) + (y - y2)) * 12
if d > 36 {
d = 36
}
col := cs[colIdx]
col = color.RGBA{
R: safeColor(int32(col.R) + d),
G: safeColor(int32(col.G) + d),
B: safeColor(int32(col.B) + d),
A: 0xff}
if !opaque {
col = cols.BlendColors(t, col, y)
}
pix[iofs] = col.R
pix[iofs+1] = col.G
pix[iofs+2] = col.B
pix[iofs+3] = col.A
}
iofs += 4
ofs++
}
ofs += stride
iofs -= istride
}
} else { // Solid images.
for z := height - 1; z >= 0; z-- {
for x := 0; x < width; x++ {
colIdx := r.cBuffer[ofs]
if colIdx < 0 || colIdx >= numCols {
pix[iofs] = background.R
pix[iofs+1] = background.G
pix[iofs+2] = background.B
pix[iofs+3] = 0xff
} else {
var y, y1, y2 int32
y = r.yBuffer[ofs]
if x == 0 {
y1 = y
} else {
y1 = r.yBuffer[ofs-1]
}
if z == 0 {
y2 = y
} else {
y2 = r.yBuffer[ofs+pw]
}
d := ((y - y1) + (y - y2)) * 12
if d > 36 {
d = 36
}
col := cs[colIdx]
pix[iofs] = safeColor(int32(col.R) + d)
pix[iofs+1] = safeColor(int32(col.G) + d)
pix[iofs+2] = safeColor(int32(col.B) + d)
pix[iofs+3] = 0xff
}
iofs += 4
ofs++
}
ofs += stride
iofs -= istride
}
}
return image
}