feat(render): 纹理图集构建与区块网格构建(面剔除/三通道/光照顶点)

This commit is contained in:
NianGao Dev
2026-08-15 22:39:44 +08:00
parent 8bdd5b047f
commit 719fe5fb2a
4 changed files with 372 additions and 0 deletions

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internal/mesh/mesh.go Normal file
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// Package mesh 区块网格构建:面剔除 + 顶点格式 + 光照(场景/渲染.md §3)。
//
// 网格在 CPU 构建(worker 池),GL 只负责上传——渲染 goroutine 不产生分配压力。
package mesh
import (
"mc/internal/block"
"mc/internal/chunk"
)
// Vertex 顶点格式(渲染.md §5):位置 + UV + 天空/方块光各 4-bit。
type Vertex struct {
X, Y, Z float32
U, V float32
Sky, Block uint8
}
// ChunkMesh 一个区块的三类网格(渲染.md §6 三 pass)。
type ChunkMesh struct {
Opaque []Vertex // 不透明(主 pass)
Cutout []Vertex // alpha test(树叶/玻璃)
Translucent []Vertex // 半透明(水,远→近排序 pass)
}
// Neighbor 邻居方块查询(跨区块面剔除用,区块管理.md §6)。
type Neighbor func(x, y, z int32) block.State
// UVFunc 纹理键 → 图集 UV(归一化坐标,含 inset)。
type UVFunc func(texKey string) (u0, v0, u1, v1 float32, ok bool)
// Builder 网格构建器。
type Builder struct {
reg *block.Registry
uv UVFunc
}
// NewBuilder 创建构建器。
func NewBuilder(reg *block.Registry, uv UVFunc) *Builder {
return &Builder{reg: reg, uv: uv}
}
// face 一个面的 4 个角偏移与朝向。
type faceDef struct {
dir [3]int32
corners [4][3]int32
}
// faces 六面定义(角顺序与 UV 顶点顺序一致)。
var faces = [6]faceDef{
{dir: [3]int32{0, 1, 0}, corners: [4][3]int32{{0, 1, 0}, {1, 1, 0}, {1, 1, 1}, {0, 1, 1}}}, // 顶
{dir: [3]int32{0, -1, 0}, corners: [4][3]int32{{0, 0, 1}, {1, 0, 1}, {1, 0, 0}, {0, 0, 0}}}, // 底
{dir: [3]int32{1, 0, 0}, corners: [4][3]int32{{1, 0, 0}, {1, 0, 1}, {1, 1, 1}, {1, 1, 0}}}, // 东(+x)
{dir: [3]int32{-1, 0, 0}, corners: [4][3]int32{{0, 0, 1}, {0, 0, 0}, {0, 1, 0}, {0, 1, 1}}}, // 西(-x)
{dir: [3]int32{0, 0, 1}, corners: [4][3]int32{{1, 0, 1}, {0, 0, 1}, {0, 1, 1}, {1, 1, 1}}}, // 南(+z)
{dir: [3]int32{0, 0, -1}, corners: [4][3]int32{{0, 0, 0}, {1, 0, 0}, {1, 1, 0}, {0, 1, 0}}}, // 北(-z)
}
// faceTexture 面方向 → 注册表纹理面名(block.Registry.Texture 参数)。
var faceTexture = [6]string{"up", "down", "east", "west", "south", "north"}
// Build 构建区块网格(面剔除:仅当邻格非完全不透明时生成该面,渲染.md §3.1)。
func (b *Builder) Build(c *chunk.Chunk, nb Neighbor) *ChunkMesh {
m := &ChunkMesh{}
blocks := c.Snapshot()
baseX, baseZ := float32(c.CX*16), float32(c.CZ*16)
for x := 0; x < 16; x++ {
for y := 0; y < chunk.Height; y++ {
for z := 0; z < 16; z++ {
s := blocks[chunk.Index(x, y, z)]
if s == block.Air {
continue
}
var target *[]Vertex
switch {
case b.reg.IsTranslucent(s):
target = &m.Translucent
case b.reg.IsCutout(s):
target = &m.Cutout
default:
target = &m.Opaque
}
wx := int32(x) + c.CX*16
wy := int32(y)
wz := int32(z) + c.CZ*16
sky, blk := c.SkyLight(x, y, z), c.BlockLight(x, y, z)
for fi, f := range faces {
nx := wx + f.dir[0]
ny := wy + f.dir[1]
nz := wz + f.dir[2]
neighbor := nb(nx, ny, nz)
if b.reg.IsOpaque(neighbor) {
continue // 面被不透明邻格遮挡(面剔除)
}
// 同类型邻格也剔除(水贴水不渲染内面;树叶相邻保留边缘,简化规则)
if neighbor != block.Air && !b.reg.IsOpaque(neighbor) &&
b.reg.IsTranslucent(neighbor) == b.reg.IsTranslucent(s) && b.reg.IsTranslucent(s) {
continue
}
texKey := b.reg.Texture(s, faceTexture[fi])
u0, v0, u1, v1, ok := b.uv(texKey)
if !ok {
u0, v0, u1, v1 = 0, 0, 1, 1
}
for _, corner := range f.corners {
*target = append(*target, Vertex{
X: baseX + float32(x) + float32(corner[0]),
Y: float32(y) + float32(corner[1]),
Z: baseZ + float32(z) + float32(corner[2]),
U: u0 + (u1-u0)*float32(cornerUV(corner, f)[0]),
V: v0 + (v1-v0)*float32(cornerUV(corner, f)[1]),
Sky: sky,
Block: blk,
})
}
}
}
}
}
return m
}
// cornerUV 角在面上的 UV 权重(0/1),顺序与 corners 一致。
func cornerUV(c [3]int32, f faceDef) [2]int32 {
var u, v int32
switch f.dir {
case [3]int32{0, 1, 0}, [3]int32{0, -1, 0}: // 顶/底:x→u,z→v
u, v = c[0], c[2]
case [3]int32{1, 0, 0}, [3]int32{-1, 0, 0}: // 东/西:z→u,y→v
u, v = c[2], 1-c[1]
default: // 南/北:x→u,y→v
u, v = c[0], 1-c[1]
}
return [2]int32{u, v}
}

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package mesh
import (
"path/filepath"
"testing"
"mc/internal/block"
"mc/internal/chunk"
)
// loadReg 加载注册表。
func loadReg(t *testing.T) *block.Registry {
t.Helper()
r, err := block.Load(filepath.Join("..", "..", "assets", "config", "blocks.json"))
if err != nil {
t.Fatalf("加载注册表失败: %v", err)
}
return r
}
// airNb 邻居查询:全部视为空气(不剔除任何面)。
func airNb(x, y, z int32) block.State { return block.Air }
// dummyUV 固定 UV(测试不关心贴图坐标)。
func dummyUV(key string) (float32, float32, float32, float32, bool) {
return 0, 0, 1, 1, true
}
// TestSingleBlock 单方块 6 面全生成:24 顶点(6 面 × 4 顶点四边形)。
func TestSingleBlock(t *testing.T) {
reg := loadReg(t)
stone, _ := reg.ID("stone")
c := chunk.New(0, 0)
c.Fill(0, 0, 0, block.NewState(stone, 0))
c.SetBlockLight(0, 0, 0, 10)
b := NewBuilder(reg, dummyUV)
m := b.Build(c, airNb)
if len(m.Opaque) != 24 {
t.Fatalf("不透明顶点期望 24,实际 %d", len(m.Opaque))
}
if len(m.Cutout) != 0 || len(m.Translucent) != 0 {
t.Fatalf("其他通道应为空: cutout=%d translucent=%d", len(m.Cutout), len(m.Translucent))
}
// 顶点光照传递
for _, v := range m.Opaque {
if v.Block != 10 {
t.Fatalf("顶点方块光期望 10,实际 %d", v.Block)
}
}
}
// TestFaceCulling 相邻不透明方块剔除共享面:2 块相邻 → 各 5 面 → 40 顶点。
func TestFaceCulling(t *testing.T) {
reg := loadReg(t)
stone, _ := reg.ID("stone")
c := chunk.New(0, 0)
c.Fill(0, 0, 0, block.NewState(stone, 0))
c.Fill(1, 0, 0, block.NewState(stone, 0))
// 邻居查询:跨区块查空气,区块内查实际方块
nb := func(x, y, z int32) block.State {
if x < 0 || x >= 16 || y < 0 || y >= chunk.Height || z < 0 || z >= 16 {
return block.Air
}
return c.Block(int(x), int(y), int(z))
}
b := NewBuilder(reg, dummyUV)
m := b.Build(c, nb)
if len(m.Opaque) != 40 {
t.Fatalf("面剔除后顶点期望 40,实际 %d", len(m.Opaque))
}
}
// TestChannels 透明分类:火把→cutout,水→translucent(渲染.md §6)。
func TestChannels(t *testing.T) {
reg := loadReg(t)
torch, _ := reg.ID("torch")
water, _ := reg.ID("water")
c := chunk.New(0, 0)
c.Fill(0, 0, 0, block.NewState(torch, 0))
c.Fill(2, 0, 0, block.NewState(water, 0))
b := NewBuilder(reg, dummyUV)
m := b.Build(c, airNb)
if len(m.Cutout) != 24 {
t.Fatalf("火把 cutout 顶点期望 24,实际 %d", len(m.Cutout))
}
if len(m.Translucent) != 24 {
t.Fatalf("水 translucent 顶点期望 24,实际 %d", len(m.Translucent))
}
if len(m.Opaque) != 0 {
t.Fatalf("不应有不透明顶点,实际 %d", len(m.Opaque))
}
}