rev: 3827f53bae88e48a594610914ba74b9512ead6dd tukan/testing/test_tmt4hw.sc -rw-r--r-- 39.0 KiB View raw Log this file
3827f53bae88 — Leonard Ritter * more work on module system 3 months ago
                                                                                
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#
    biquadratic interpolation
    with raymarching

#
    tetrahedral marching triangles

    step 1: identify by mask for each tet if its relevant vertices are partially set
    mask has 8 bits, 3 tets per bitarray = 2 x 24 bits
    all bits set or all bits not set = ignore, otherwise generate surface

    one tet is handled per thread

import ..tukan.voxel
let voxel = tukan.voxel

using import glm
using import glsl
using import Array
using import Box
using import struct
using import enum
using import ..tukan.gl
using import ..tukan.bitmap
using import ..tukan.packing
using import ..tukan.random
using import ..tukan.color
using import ..tukan.perfect_hash
using import ..tukan.raytrace
using import ..tukan.sdf
using import ..tukan.sdl
using import ..tukan.rotation
using import ..tukan.brdf
using import ..tukan.mesh
using import ..tukan.normal
using import ..tukan.projection
using import ..tukan.derivative
using import ..tukan.isosurface
using import ..tukan.hash
using import .testfragment

let USE_PACKING =
    true
    #false

# regress to trilinear filtering
let USE_TRILINEAR_FILTER =
    true
    #false

let USE_WEIGHT_BLUR =
    #true
    false

let
    QUADRATIC_APPROX = 2
    LINEAR_APPROX = 1
    RAYMARCHED = 0

let RAYTRACE_MODE = QUADRATIC_APPROX

# reserve 10MB for each voxel buffer
    at 4 bytes per voxel
let MAX_VOXELS = ((20 * (1 << 20)) // 4)

# pack quantization
let PACKING_Q = 1.0

embed
    let RAYMARCH_MINDIST = (1.0 / 16.0)
    let RAYMARCH_STEPS = 16

#embed
    let RAYMARCH_MINDIST = (1.0 / 256.0)
    let RAYMARCH_STEPS = 50

let BINDING_BUF_CELLS_IN = 1
let BINDING_BUF_CELLS_IN_INFO = 2
let BINDING_BUF_CELLS_OUT = 3
let BINDING_BUF_CELLS_OUT_INFO = 4
let BINDING_BUF_DRAW_CMD = 3
let BINDING_BUF_COMPUTE_CMD = 4
let BINDING_BUF_VERTEX_ATTR1_IN = 5
let BINDING_BUF_VERTEX_ATTR1_OUT = 6

let IMAGE_TARGET_ATLAS = 1

let UNIFORM_LEVEL = 1
let UNIFORM_PROGRAM = 2
let UNIFORM_SCREEN_SAMPLER = 3
let UNIFORM_DIVISOR = 4
let UNIFORM_ATLAS_SAMPLER = 5

let ProgramVoxelizeInit = 0
let ProgramVoxelize = 1
let ProgramSimplify = 2

let sqrt3 = (sqrt 3.0)
let THREADSIZE = 256

let COEFF_ATLAS_SIZE = 256

let corner-vectors =
    arrayof vec3
        vec3 0 0 0
        vec3 1 0 0
        vec3 0 1 0
        vec3 1 1 0
        vec3 0 0 1
        vec3 1 0 1
        vec3 0 1 1
        vec3 1 1 1

run-stage;

struct CellValsInfo plain
    count : u32

struct CellVals plain
    # each entry holds a key
    entries : (array u32)

buffer buf-cells-in : CellVals
    binding = BINDING_BUF_CELLS_IN
    \ readonly coherent restrict

buffer buf-cells-in-info : CellValsInfo
    binding = BINDING_BUF_CELLS_IN_INFO
    \ readonly coherent restrict

buffer buf-cells-out : CellVals
    binding = BINDING_BUF_CELLS_OUT
    \ writeonly coherent restrict

buffer buf-cells-out-info : CellValsInfo
    binding = BINDING_BUF_CELLS_OUT_INFO
    \ coherent restrict

let CubeData =
    struct CubeData plain
        # w = key of cube, also index into voxel texture
        key : u32

struct VertexAttr1 plain
    # cell key + simplex index, 4x u8 weights
    entries : (array CubeData)

buffer buf-vertex-attr1-in : VertexAttr1
    binding = BINDING_BUF_VERTEX_ATTR1_IN
    \ readonly coherent restrict

buffer buf-vertex-attr1-out : VertexAttr1
    binding = BINDING_BUF_VERTEX_ATTR1_OUT
    \ writeonly coherent restrict

uniform u-program : i32
    location = UNIFORM_PROGRAM

uniform u-level : i32
    location = UNIFORM_LEVEL

uniform smp-screen : sampler2D
    location = UNIFORM_SCREEN_SAMPLER

uniform smp-atlas : sampler3D
    location = UNIFORM_ATLAS_SAMPLER

struct DispatchIndirectCommand plain
    num_groups_x : u32 = 1
    num_groups_y : u32 = 1
    num_groups_z : u32 = 1

struct DispatchIndirectCommandI plain
    command : DispatchIndirectCommand

struct DrawArraysIndirectCommand plain
    count : u32 = 0
    instanceCount : u32 = 0
    first : u32 = 0
    baseInstance : u32 = 0

struct DrawArraysIndirectCommandI plain
    command : DrawArraysIndirectCommand

buffer buf-compute-cmd : DispatchIndirectCommandI
    binding = BINDING_BUF_COMPUTE_CMD
    \ writeonly coherent restrict

buffer buf-draw-cmd : DrawArraysIndirectCommandI
    binding = BINDING_BUF_DRAW_CMD
    \ writeonly coherent restrict

uniform u-divisor : i32
    location = UNIFORM_DIVISOR

fn setup-compute-command ()
    local_size 1 1 1
    let divisor = ((deref u-divisor) as u32)
    buf-compute-cmd.command =
        DispatchIndirectCommand
            ((deref buf-cells-in-info.count) + divisor - 1:u32) // divisor
            1
            1
    ;

fn setup-draw-arrays-command ()
    local_size 1 1 1
    buf-draw-cmd.command =
        DrawArraysIndirectCommand
            deref buf-cells-in-info.count
            1
            0
            0
    ;

fn simple-sphere (p)
    (length p) - 0.5

fn nine-spheres (p)
    let x = (deref shglobals.time)
    r := (mix 0.1 0.2 ((sin x) * 0.5 + 0.5))
    d := (sqrt 0.5) * 0.4
    sdSmoothAnd
        sdSmoothOr
            (length p) - 0.5
            min
                (length (p - (vec3 d d d))) - r
                (length (p - (vec3 -d d d))) - r
                (length (p - (vec3 d -d d))) - r
                (length (p - (vec3 -d -d d))) - r
            0.1
        * -1.0
            min
                (length (p - (vec3 d d -d))) - r
                (length (p - (vec3 -d d -d))) - r
                (length (p - (vec3 d -d -d))) - r
                (length (p - (vec3 -d -d -d))) - r
        0.1

fn twoballs (p)
    let x = (deref shglobals.time)
    x := ((sin x) * 0.5 + 0.5) * 0.5
    sdSmoothOr
        (length (p - (vec3 0.0 0 x))) - 0.25
        (length (p - (vec3 0.0 0 -x))) - 0.25
        0.2

fn doubletori (p)
    let x = (deref shglobals.time)
    let xz =
        anglevector-rotate
            anglevector -x
            p.xz
    let p1 =
        vec3
            xz.x
            p.y
            xz.y
    let p2 =
        vec3
            anglevector-rotate
                anglevector x
                p.xy
            p.z

    'sdSmoothOr
        sdmDist
            sdTorus p1.xzy (vec2 0.5 0.05)
            sdMaterial
                vec4 1.0 0.5 0.3 1.0
        sdmDist
            sdTorus p2 (vec2 0.4 0.1)
            sdMaterial
                vec4 0.3 0.5 1.0 1.0
                roughness = 0.1
        0.2

fn tentacles (p)
    p := (vec3 p.x (p.y - 0.2) p.z)
    let x = (deref shglobals.time)
    r := (mix -1.0 1.0 ((sin x) * 0.5 + 0.5))

    local d =
        sdmDist inf
            sdMaterial (vec4 0.0)
    for a in (range 6)
        a := a as f32
        q1 := (anglevector (radians (360.0 * a / 6.0))) * 1.0
        q2 := (anglevector (radians (360.0 * (a + 2.0 * r) / 6.0))) * 0.2
        b :=
            sdBezier
                vec3 0 -0.8 0
                vec3 q1.x -0.6 q1.y
                vec3 q2.x 0.4 q2.y
                p
        bbby := b.y * b.y * b.y
        throb := (sin (2.0 * pi * (bbby - x * 0.1 + a * 0.3) * 12.0))
        armlen := b.y

        b := b.x - 0.09 * (exp -b.y) + throb * 0.01 * (1.0 - bbby)

        #d = (min d b)
        veinmatmix :=
            clamp (armlen - throb * 0.2) 0.0 1.0
        d =
            'sdSmoothOrM (deref d)
                sdmDist (b / 1.1)
                    sdMaterial
                        mix
                            vec4 0.3 0.5 1.0 1.0
                            vec4 1.0 0.3 0.3 1.0
                            veinmatmix
                        roughness =
                            mix 1.0 0.1 veinmatmix
                sdMaterial
                    vec4 2.0 1.8 0.5 1.0
                    roughness = 1.0
                0.15
                4.0
    deref d

fn two-boxes (p)
    let x = (deref shglobals.time)
    let p1 =
        vec3
            anglevector-rotate
                anglevector -x
                p.xy
            p.z
    let p2 =
        vec3
            p.x
            anglevector-rotate
                anglevector (x * 0.917)
                p.yz
    'sdSmoothOr
        sdmDist
            sdBox p1 (vec3 0.33)
            sdMaterial
                vec4 1.0 0.5 0.3 1.0
        sdmDist
            sdBox p2 (vec3 0.33)
            sdMaterial
                vec4 0.3 0.5 1.0 1.0
                roughness = 0.1
        0.2

fn two-boxes-merge (p)
    let d =
        vec3 0.3
    let sz =
        vec3 0.5
    let x = (deref shglobals.time)
    r := (mix 1.0 0.2 ((sin x) * 0.5 + 0.5))
    'sdSmoothAnd
        'sdSmoothOr
            sdmDist
                #sdSphere
                    p - (vec3 0.01)
                    1.0
                sdUberprim
                    p - (vec3 0.01)
                    vec4 1.0 1.0 0.05 0.05
                    vec3 0.5 0.05 0.0
                sdMaterial
                    vec4 1.0 0.9 0.3 1.0
                    metallic = 1.0
            'sdSmoothOr
                sdmDist
                    sdBox (p - d) sz
                    sdMaterial
                        vec4 1.0 0.5 0.3 1.0
                sdmDist
                    sdBox (p + d) sz
                    sdMaterial
                        vec4 0.3 0.5 1.0 1.0
                        roughness = 0.2
                0.5
            0.05
        sdmDist
            -
                sdSphere
                    p - (vec3 0.0 0.0 -0.5)
                    r
            sdMaterial
                vec4 0.5 0.3 1.0 1.0
        0.1

fn two-boxes-merge-deluxe (p)
    let d =
        vec3 0.3
    let sz =
        vec3 0.5
    let x = (deref shglobals.time)
    let sp1 =
        p - (vec3 0.0 0.0 -0.5)
    cwave := (sin (x * 10.0 + 2.0 * pi * 10.0 * (length sp1)))
    wave := cwave * 0.5 + 0.5
    r := (mix 1.0 0.2 ((sin x) * 0.5 + 0.5))
    'sdSmoothOr
        'sdSmoothAnd
            'sdSmoothOr
                sdmDist
                    #sdSphere
                        p - (vec3 0.01)
                        1.0
                    sdUberprim
                        p - (vec3 0.01)
                        vec4 1.0 1.0 0.05 0.05
                        vec3 0.5 0.05 0.0
                    sdMaterial
                        vec4 1.0 0.9 0.3 1.0
                        metallic = 1.0
                'sdSmoothOr
                    sdmDist
                        ((sdBox (p - d) (sz - 0.1)) - 0.1 + cwave * 0.01) / 1.3
                        sdMaterial
                            mix
                                vec4 1.0 0.5 0.3 1.0
                                (vec4 1.0 0.5 0.3 1.0) * 0.3
                                wave
                    sdmDist
                        sdBox (p + d) sz
                        sdMaterial
                            vec4 0.3 0.5 1.0 1.0
                            roughness = 0.2
                    0.5
                0.05
            sdmDist
                - (sdSphere sp1 r)
                sdMaterial
                    vec4 0.5 0.3 1.0 1.0
            0.1
        sdmDist
            sdEllipsoid
                p - (vec3 0.2 0.0 0.0)
                vec3 0.3 0.4 1.0
            sdMaterial
                vec4 0.3 1.0 0.5 1.0
        0.1

fn one-box (p)
    sdBox p (vec3 0.33)

fn matmapf (p)
    do
        p := p.yzx * 2.0
        (two-boxes-merge p) * 0.5
    #doubletori p
    #two-boxes p
    #tentacles p

# single sphere:
    256^3: 89240 cells (best: 0.3ms)
    1024^3: 1427240 cells (best: 3.5ms)
# min: 104567 at 256^3
fn mapf (p)
    #let x = ((radians (deref shglobals.time)) * 10.0)
    #let xz =
        anglevector-rotate
            anglevector -x
            p.xz
    #let p =
        vec3
            xz.x
            p.y
            xz.y
    #simple-sphere p
    #twoballs p
    #doubletori p
    #nine-spheres p
    #two-boxes p
    #one-box p
    (matmapf p) as f32

fn normalmapf (p r)
    - (sdNormalFast mapf p r)

fn subdivide-cell (key)
    let level = ((deref u-level) as u32)
    let r = (/ (f32 (1:u32 << level)))
    let d = (2.0 * r)
    #let rlimit =
        if (level == 8:u32) r
        else (sqrt3 * r)

    key := (key << 3:u32)

    ucoord := (unpack-morton3x10 key)
    coord := (vec3 ucoord) * d - 1.0 + r

    global cells : (array u32 8)
    global written = 0:u32

    fn test-cell (i ofs key coord r)
        let rlimit = (sqrt3 * r)
        key := key | i
        pos := coord + ofs
        let dist = (mapf pos)
        let hit = ((abs dist) < rlimit)
        if hit
            cells @ (deref written) = key
            written += 1:u32

    inline test-cell (i ofs)
        test-cell i ofs key coord r

    test-cell 0:u32 (vec3 0 0 0)
    test-cell 1:u32 (vec3 d 0 0)
    test-cell 2:u32 (vec3 0 d 0)
    test-cell 3:u32 (vec3 d d 0)
    test-cell 4:u32 (vec3 0 0 d)
    test-cell 5:u32 (vec3 d 0 d)
    test-cell 6:u32 (vec3 0 d d)
    test-cell 7:u32 (vec3 d d d)

    # commit
    if (written != 0:u32)
        let id = (atomicAdd buf-cells-out-info.count (deref written))
        for i in (range (deref written))
            buf-cells-out.entries @ (id + i) = (cells @ i)

uniform img-target-atlas :
    do
        static-if USE_PACKING
            image3D rgba8_snorm
        else
            image3D rgba32f
    binding = IMAGE_TARGET_ATLAS
    \ coherent writeonly restrict

fn simplify-cell (key)
    let level = (((deref u-level) as u32) - 1)
    let r = (/ (f32 (1:u32 << level)))
    let d = (2.0 * r)

    ucoord := (unpack-morton3x10 key)
    coord := (vec3 ucoord) * d - 1.0 + r

    let id = (atomicAdd buf-cells-out-info.count 1:u32)
    let data = (buf-vertex-attr1-out.entries @ id)

    let L =
        static-if USE_TRILINEAR_FILTER r
        elseif USE_WEIGHT_BLUR d
        else d

    let icoord = (ivec3 ucoord)
    inline get (x y z)
        ofs := ((vec3 x y z) * L)
        pos := (coord + ofs)
        vec4
            (mapf pos) / (d * PACKING_Q)
            normalmapf pos (r * 0.5)

    data.key = key
    static-if USE_TRILINEAR_FILTER
        inline store_val (x y z)
            let sx sy sz = (x * 2 - 1) (y * 2 - 1) (z * 2 - 1)
            d := (get sx sy sz)
            imageStore img-target-atlas
                icoord + (ivec3 x y z)
                d
        store_val 0 0 0
        store_val 1 0 0
        store_val 0 1 0
        store_val 1 1 0
        store_val 0 0 1
        store_val 1 0 1
        store_val 0 1 1
        store_val 1 1 1
    else
        inline store_val (x y z)
            imageStore img-target-atlas
                icoord + (ivec3 x y z)
                get x y z

        store_val -1 -1 -1
        store_val  0 -1 -1
        store_val  1 -1 -1
        store_val -1  0 -1
        store_val  0  0 -1
        store_val  1  0 -1
        store_val -1  1 -1
        store_val  0  1 -1
        store_val  1  1 -1

        store_val -1 -1  0
        store_val  0 -1  0
        store_val  1 -1  0
        store_val -1  0  0
        store_val  0  0  0
        store_val  1  0  0
        store_val -1  1  0
        store_val  0  1  0
        store_val  1  1  0

        store_val -1 -1  1
        store_val  0 -1  1
        store_val  1 -1  1
        store_val -1  0  1
        store_val  0  0  1
        store_val  1  0  1
        store_val -1  1  1
        store_val  0  1  1
        store_val  1  1  1

    ;

fn voxelize-init ()
    let index = (deref gl_GlobalInvocationID.x)
    subdivide-cell index

fn voxelize ()
    let index = (deref gl_GlobalInvocationID.x)
    if (index < buf-cells-in-info.count)
        subdivide-cell (deref (buf-cells-in.entries @ index))

fn simplify ()
    local_size THREADSIZE 1 1
    let index = (deref gl_GlobalInvocationID.x)
    if (index < buf-cells-in-info.count)
        simplify-cell (deref (buf-cells-in.entries @ index))

fn supershader ()
    local_size THREADSIZE 1 1
    let mode = (deref u-program)
    switch mode
    case ProgramVoxelizeInit
        voxelize-init;
    case ProgramVoxelize
        voxelize;
    #case ProgramSimplify
        simplify;
    default
        ;;

fn calc-projection ()
    let aspect = (vec2 (/ (deref shglobals.aspect)) 1.0)
    'ifp-perspective ProjectionSetup aspect 0.1

inout-geometry geom_data : CubeData
fn rasterize-vert ()
    let index = ((deref gl_VertexID) as u32)
    let data = (deref (buf-vertex-attr1-in.entries @ index))
    geom_data.out = data
    ;

inline transform-rotate (p)
    let a = ((deref shglobals.time) * 0.2)
    let c s = (cos a) (sin a)
    vec3
        c * p.x - s * p.z
        p.y
        s * p.x + c * p.z

inline transform-invert-rotate (p)
    let a = ((deref shglobals.time) * -0.2)
    let c s = (cos a) (sin a)
    vec3
        c * p.x - s * p.z
        p.y
        s * p.x + c * p.z

inline transform-pos (p)
    v := (transform-rotate p)
    vec3 v.xy (v.z + 1.0)

inout depthval : f32
inout ray_origin : vec3
inout ray_dir : vec3
inout cube_data : CubeData flat
fn rasterize-geom ()
    input_primitive points
    output_primitive triangle_strip 14

    let data = (geom_data.in @ 0)

    let key = (deref data.key)

    let level = (((deref u-level) as u32) - 1)
    let r = (/ (f32 (1:u32 << level)))
    let d = (2.0 * r)
    ucoord := (unpack-morton3x10 key)
    coord := (vec3 ucoord) * d - 1.0

    cube_data.out.key = data.key

    inline write-vertex (i)
        let p = (cube-vertex i)
        p := (vec3 p.x p.y (1 - p.z))
        ray_origin.out = p

        coord := coord + (vec3 p) * d
        coord := (transform-pos coord)

        ray_dir.out =
            transform-invert-rotate coord

        let proj =
            calc-projection;

        let pcoord =
            'project proj
                vec4 coord 1.0

        depthval.out = coord.z
        gl_Position = pcoord
        EmitVertex;

    for i in (range 14)
        write-vertex i
    EndPrimitive;
    ;

fn pack-surfel-data (normal depth color matdata)
    let normal =
        bitcast (packSnorm2x16 (pack_normal_snorm normal)) f32
    let color =
        #bitcast (packUnorm4x8 color) f32
        bitcast
            |
                ((clamp (color.r / 4.0) 0.0 1.0) * 1023.0 + 0.5) as u32
                (((clamp (color.g / 4.0) 0.0 1.0) * 1023.0 + 0.5) as u32) << 10:u32
                (((clamp (color.b / 4.0) 0.0 1.0) * 1023.0 + 0.5) as u32) << 20:u32
            f32

    let matdata =
        bitcast (packUnorm4x8 matdata) f32
    vec4 normal matdata color depth

fn unpack-surfel-data (frag)
    let normal =
        unpack_normal_snorm (unpackSnorm2x16 (bitcast frag.x u32))
    let matdata =
        unpackUnorm4x8 (bitcast frag.y u32)
    let color =
        #unpackUnorm4x8 (bitcast frag.z u32)
        bitcast frag.z u32
    color :=
        vec3
            ((color & 0x3ff:u32) as f32 / 1023.0) * 4.0
            (((color >> 10:u32) & 0x3ff:u32) as f32 / 1023.0) * 4.0
            (((color >> 20:u32) & 0x3ff:u32) as f32 / 1023.0) * 4.0
    _
        normal
        frag.w
        color
        matdata

out out_Color : vec4
    binding = 0
fn rasterize-frag ()
    fragment_depth depth_less
    let level = (((deref u-level) as u32) - 1)
    let r = (/ (f32 (1:u32 << level)))
    let d = (2.0 * r)
    let key = (deref cube_data.in.key)
    ucoord := (unpack-morton3x10 key)
    icoord := (ivec3 ucoord)
    coord := (vec3 ucoord) * d - 1.0

    ro := (deref ray_origin.in)
    rd := (normalize (deref ray_dir.in))

    far := (iCubeFar (ro - 0.5) rd)

    let delta =
        static-if USE_TRILINEAR_FILTER 0.5
        elseif USE_WEIGHT_BLUR -0.5
        else 0.0

    inline load_val (x y z)
        pos := (vec3 icoord) + (vec3 x y z) + delta
        pos := pos / (COEFF_ATLAS_SIZE as f32)
        (textureLod smp-atlas pos 0) . x

    inline load_normal (x y z)
        pos := (vec3 icoord) + (vec3 x y z) + delta
        pos := pos / (COEFF_ATLAS_SIZE as f32)
        (textureLod smp-atlas pos 0) . yzw

    inline interpolate (o)
        static-if USE_WEIGHT_BLUR
            let k = 0.5
            let
                w000 =
                    load_val o.x o.y o.z
                w100 =
                    load_val (o.x + k) o.y o.z
                w010 =
                    load_val o.x (o.y + k) o.z
                w110 =
                    load_val (o.x + k) (o.y + k) o.z
                w001 =
                    load_val o.x o.y (o.z + k)
                w101 =
                    load_val (o.x + k) o.y (o.z + k)
                w011 =
                    load_val o.x (o.y + k) (o.z + k)
                w111 =
                    load_val (o.x + k) (o.y + k) (o.z + k)
            * 0.125
                +
                    w000
                    w100
                    w010
                    w110
                    w001
                    w101
                    w011
                    w111
        else
            load_val o.x o.y o.z

    inline interpolate-normal (o)
        #sdNormalFast interpolate o 0.01
        normalize
            static-if USE_WEIGHT_BLUR
                let k = 0.5
                let
                    w000 =
                        load_normal o.x o.y o.z
                    w100 =
                        load_normal (o.x + k) o.y o.z
                    w010 =
                        load_normal o.x (o.y + k) o.z
                    w110 =
                        load_normal (o.x + k) (o.y + k) o.z
                    w001 =
                        load_normal o.x o.y (o.z + k)
                    w101 =
                        load_normal (o.x + k) o.y (o.z + k)
                    w011 =
                        load_normal o.x (o.y + k) (o.z + k)
                    w111 =
                        load_normal (o.x + k) (o.y + k) (o.z + k)
                * 0.125
                    +
                        w000
                        w100
                        w010
                        w110
                        w001
                        w101
                        w011
                        w111
            else
                load_normal o.x o.y o.z

    # reconstruct 1D quadratic coefficients from three samples

    embed
        # option A: sample from enter, middle and exit
        c0 := (interpolate ro)
        c1 := (interpolate (ro + rd * (far * 0.5)))
        c2 := (interpolate (ro + rd * far))

        2A := 4.0 * (c2 + c0 - 2.0 * c1)
        NB := -4.0 * c1 + 3.0 * c0 + c2
        2C := 2.0 * c0

        # from
            Numerically Stable Method for Solving Quadratic Equations
            https://people.csail.mit.edu/bkph/articles/Quadratics.pdf
        k := NB * NB - 2A * 2C
        if (k < 0.0)
            discard!;
        k := (sqrt k)
        let pred = (NB > 0.0)
        let q0 q1 =
            /
                ? pred 2C (NB - k)
                ? pred (NB + k) 2A
            /
                ? pred (NB + k) 2C
                ? pred 2A (NB - k)
        k :=
            ? (q0 < 0.0) q1 q0
        #q1 := (? (q1 > q0) q1 inf)
        if ((k < -0.01) | (k > 1.01))
            discard!;
        t := k * far
    #embed
        local t = 0.0
        local count = 0
        for i in (range RAYMARCH_STEPS)
            p := ro + rd * t
            let L = PACKING_Q
            dist := ((interpolate (deref p)) * L)
            count += 1
            if (dist < RAYMARCH_MINDIST)
                break;
            t += dist
            if (t > far)
                discard!;
        t := (deref t)

    p := ro + rd * t

    q :=
        interpolate p

    #n :=
        - (sdNormalFast interpolate p 0.01)
    n :=
        #normalmapf coord (r / 4.0)
        #- (sdNormalFast interpolate p 0.01)
        interpolate-normal p
        #normalize
            vec3
                dFdx p.z
                dFdy p.z
                0

    coord := coord + p * d
    #let dist = (matmapf coord)
    #let material =
        dist.material

    p := (transform-pos coord)
    #n := (transform-rotate n)

    gl_FragDepth = (0.1 / p.z)

    out_Color =
        pack-surfel-data n
            p.z
            do
                #vec4
                    rd * 0.5 + 0.5
                    1
                #material.albedo
                #vec4 (rd * 0.5 + 0.5) 1
                #vec4 ((deref p) * 0.5 + 0.5) 1
                #vec4 (normhue ((dist as f32) * 0.5 + 0.5)) 1
                #vec4 (normhue (count / RAYMARCH_STEPS)) 1
                #vec4 (normhue (t / (max 0.01 far))) 1
                vec4 1
            do
                #vec4 material.roughness material.metallic 0 0
                vec4 0.5 0 0 0

#
    let level = (((deref u-level) as u32) - 1)
    let r = (/ (f32 (1:u32 << level)))
    let d = (2.0 * r)
    let coord = (deref modelpos.in)

    uv := ((deref gl_FragCoord) . xy) / (vec2 (deref shglobals.size))
    uv := (uv * 2.0 - 1.0) * (vec2 shglobals.aspect 1)

    let rd = (normalize (vec3 uv 1))
    #let rd = (normalize (deref viewpos.in))

    inline fetchmap (p)

        # ivec3 0..2 0..2 0..2 -> vec3 (n-1)*2*r
        (vec3 (p * 2 - 1)) * r

    inline mapavgf (p)
        * 0.125
            +
                mapf (p + (vec3 -r -r -r))
                mapf (p + (vec3  r -r -r))
                mapf (p + (vec3 -r  r -r))
                mapf (p + (vec3  r  r -r))
                mapf (p + (vec3 -r -r  r))
                mapf (p + (vec3  r -r  r))
                mapf (p + (vec3 -r  r  r))
                mapf (p + (vec3  r  r  r))

    #inline mapf (p)
        let pl = (vec4 0 1 0 0)
        #p.z
        let r = ((sin (deref shglobals.time)) * 0.5 + 0.5)
        #(sqrt (dot p p)) - r

        z := (p.z - 1.0) * 0.5
        r := 0.5
        (p.x * p.x + p.y * p.y) / (r * r) - z * z

    let c =
        vec4
            mapavgf (deref (modelcorners.in @ 0))
            mapavgf (deref (modelcorners.in @ 1))
            mapavgf (deref (modelcorners.in @ 2))
            mapavgf (deref (modelcorners.in @ 3))

    #c := c * c * (sign c)

    inline midpoint (v1 v2)
        d := (mapf ((modelcorners.in @ v1 + modelcorners.in @ v2) * 0.5))
        #d := d * d * (sign d)
        #d * 2.0 - ((c @ v1) + (c @ v2)) * 0.5
        d


    let m1 =
        vec3
            midpoint 2 1
            midpoint 0 2
            midpoint 1 0

    let m2 =
        vec3
            midpoint 0 3
            midpoint 1 3
            midpoint 2 3

    let hit near far =
        iQuadricSimplex (deref corners.in)
            #\ (c * c * (sign c)) (m1 * m1 * (sign m1)) (m2 * m2 * (sign m2))
            \ c m1 m2
            #vec4 2
            #vec3 -1
            #vec3 -1
            vec3 0
            rd

    if (not hit)
        discard!;

    #corners.in @ 0

    #let coord = (rd *

    coord :=
        +
            modelcorners.in @ 0 * near.b.x
            modelcorners.in @ 1 * near.b.y
            modelcorners.in @ 2 * near.b.z
            modelcorners.in @ 3 * near.b.w

    let dist = (matmapf coord)
    let material =
        dist.material
    let n =
        #normalmapf coord (r / 32.0)
        - near.n

    gl_FragDepth = (0.1 / (rd.z * near.t))

    # rotate it a little
    embed
        let a = ((deref shglobals.time) * 0.2)
        let c s = (cos a) (sin a)

        n :=
            vec3
                c * n.x - s * n.z
                n.y
                s * n.x + c * n.z

    out_Color =
        pack-surfel-data n
            deref depthval.in
            do
                #vec4
                    rd * 0.5 + 0.5
                    1
                #material.albedo
                vec4 1
            do
                #vec4 material.roughness material.metallic 0 0
                vec4 0.5 0 0 0

uniform u-level : i32
    location = UNIFORM_LEVEL

fn mixdown (uv)
    #let t = (deref shglobals.time)
    let size =
        vec2 (deref shglobals.size)
    let uv2 =
        (uv * 2.0 - 1.0) * (vec2 shglobals.aspect 1)
    let uv = (ivec2 ((deref gl_FragCoord) . xy + 0.5))

    let col =
        texelFetch smp-screen uv 0
    let normal depth color matdata = (unpack-surfel-data col)
    if (depth == 0.0)
        return
            vec4 0.1 0.1 0.2 1
    let proj =
        calc-projection;
    let coord =
        vec3 ((uv2 * 2.0 - 1.0) * depth / proj.aspect) depth
    let rd = (normalize coord)

    let l =
        normalize
            vec3 0.5 -1.0 0.25
    let lambert =
        max 0.0 (dot normal l)

    let albedo = color.rgb
    let ambient =
        ((dot normal (vec3 0.0 -1.0 0.0)) * 0.5 + 0.5) * 0.1
    let exposure = 2.0

    glow :=
        max 0.0 ((max color.r color.g color.b) - 1.0)

    let roughness = matdata.x
    let metallic = matdata.y
    let color =
        linear->sRGB
            tonemap
                * exposure
                    mix
                        +
                            ambient * albedo * (1.0 - metallic)
                            * lambert
                                BRDF albedo
                                    roughness
                                    metallic
                                    \ l rd normal
                        albedo
                        glow

    return
        vec4 color 1.0
        #vec4
            #\ uv 0.0
            #normal * 0.5 + 0.5
            vec3
                (dot normal (normalize (vec3 0 -1 0))) * 0.5 + 0.5
            #normhue depth
            #normhue (radius / 16.0)
            #normhue (w / 8.0)
            1.0

fn visualize-buffer (uv)
    #let t = (deref shglobals.time)
    let size =
        vec2 (deref shglobals.size)
    let uv2 =
        (uv * 2.0 - 1.0) * (vec2 shglobals.aspect 1)
    let uv = (ivec2 ((deref gl_FragCoord) . xy + 0.5))

    let col =
        texelFetch smp-screen uv 0
    let normal depth color matdata = (unpack-surfel-data col)
    if (depth == 0.0)
        return
            vec4 0 0 0 1

    return
        vec4
            normal * -0.5 + 0.5
            #normhue ((depth * 8.0) % 1.0)
            #normhue (radius / 16.0)
            #color.xyz
            1.0

fn shader (uv)
    #mixdown uv
    visualize-buffer uv

inline main ()

    # pass overview:
        in: compute 4 * 4 * 4
        per thread:
            traverse 1/64th of octree
        for each leaf found:
            increase atomic counter in indirect draw call argument to obtain index
            append position + normal as vec4 (xyz, packed normal)
            append color as i32
                gamma compressed RGB10 values
                values >= 256 are emissive
                2 bits left for ?
            append material props as i32
                * roughness
                * metallic
                * film thickness
                * waxiness?
                * hue rotation?
                * UV activeness?
                * snowy glitter?

        in: indirect draw call argument
        out: rasterized voxel cubes

    let NUM_CMD_BUFFERS = 1

    global compute_cmd_buffers = (GL.CreateBuffer)
    setup-ssbo compute_cmd_buffers buf-compute-cmd NUM_CMD_BUFFERS

    global draw_cmd_buffers = (GL.CreateBuffer)
    setup-ssbo draw_cmd_buffers buf-draw-cmd NUM_CMD_BUFFERS

    let NUM_BUFFERS = 2

    global cell_info_buffers =
        arrayof GL.uint
            GL.CreateBuffer;
            GL.CreateBuffer;

    global cell_buffers =
        arrayof GL.uint
            GL.CreateBuffer;
            GL.CreateBuffer;
    let cell_info_buffer_sz = (sizeof u32)
    let cell_buffer_sz = ((sizeof u32) * MAX_VOXELS)
    for i in (range (NUM_BUFFERS as u32))
        let buf = (cell_info_buffers @ i)
        GL.NamedBufferData buf (i32 cell_info_buffer_sz) null GL.STREAM_COPY
        GL.BindBufferRange GL.SHADER_STORAGE_BUFFER (BINDING_BUF_CELLS_IN_INFO + i)
            \ buf 0:i64 (i64 cell_info_buffer_sz)
        let buf = (cell_buffers @ i)
        GL.NamedBufferData buf (i32 cell_buffer_sz) null GL.STREAM_COPY
        GL.BindBufferRange GL.SHADER_STORAGE_BUFFER (BINDING_BUF_CELLS_IN + i)
            \ buf 0:i64 (i64 cell_buffer_sz)

    global vertex_buffer = (GL.CreateBuffer)
    let vertex_buffer_sz = ((sizeof CubeData) * MAX_VOXELS)
    GL.NamedBufferData vertex_buffer (i32 vertex_buffer_sz) null GL.STREAM_COPY

    global fb-scene-color = (GL.CreateTexture GL.TEXTURE_2D)
    'setup fb-scene-color
        size = (ivec2 2048 2048)
        format = GL.RGBA32F
    do
        let h = 2048
        GL.ClearTexImage fb-scene-color 0 GL.RGBA GL.FLOAT null

    global coeff-atlas = (GL.CreateTexture GL.TEXTURE_3D)
    'setup coeff-atlas
        size = (ivec3 COEFF_ATLAS_SIZE)
        format =
            do
                static-if USE_PACKING GL.RGBA8_SNORM
                else GL.RGBA32F
        mag-filter = GL.LINEAR

    global rb-scene-depth = (GL.CreateRenderbuffer)
    setup-renderbuffer rb-scene-depth 2048 2048
        format = GL.DEPTH_COMPONENT
    global fb-scene = (GL.CreateFramebuffer)
    setup-framebuffer fb-scene
        color = fb-scene-color
        rb-depth = rb-scene-depth

    global vao-empty = (GL.CreateVertexArray)

    global pg-rasterize = (GL.CreateProgram)
    call
        attach-shaders (deref pg-rasterize)
            vertex = rasterize-vert
            geometry = rasterize-geom
            fragment = rasterize-frag
            #debug = true

    global pg-supershader = (GL.CreateProgram)
    call
        attach-shaders (deref pg-supershader)
            compute = supershader

    global pg-simplify = (GL.CreateProgram)
    call
        attach-shaders (deref pg-simplify)
            compute = simplify
            #debug = true

    global pg-setup-compute = (GL.CreateProgram)
    call
        attach-shaders (deref pg-setup-compute)
            compute = setup-compute-command
            #debug = true

    global pg-setup-draw = (GL.CreateProgram)
    call
        attach-shaders (deref pg-setup-draw)
            compute = setup-draw-arrays-command
            #debug = true

    inline per-frame-setup (size pg-test frame)

        GL.BindTextureUnit 0 fb-scene-color
        GL.Uniform smp-screen 0

        inline bind-read-buffer (i)
            GL.BindBufferRange GL.SHADER_STORAGE_BUFFER
                BINDING_BUF_CELLS_IN
                cell_buffers @ i
                \ 0:i64 (i64 cell_buffer_sz)
            GL.BindBufferRange GL.SHADER_STORAGE_BUFFER
                BINDING_BUF_CELLS_IN_INFO
                cell_info_buffers @ i
                \ 0:i64 (i64 cell_info_buffer_sz)

        inline clear-buffer-count (i)
            let buf = (cell_info_buffers @ i)
            let ptr =
                GL.MapNamedBufferRange buf 0 (sizeof u32)
                    | GL.MAP_WRITE_BIT
                        GL.MAP_INVALIDATE_BUFFER_BIT
                        #GL.MAP_UNSYNCHRONIZED_BIT
            let ptr = (bitcast ptr (mutable pointer CellValsInfo))
            ptr.count = 0:u32
            GL.UnmapNamedBuffer buf

        inline bind-write-buffer (i)
            clear-buffer-count i
            GL.BindBufferRange GL.SHADER_STORAGE_BUFFER
                BINDING_BUF_CELLS_OUT
                cell_buffers @ i
                \ 0:i64 (i64 cell_buffer_sz)
            GL.BindBufferRange GL.SHADER_STORAGE_BUFFER
                BINDING_BUF_CELLS_OUT_INFO
                cell_info_buffers @ i
                \ 0:i64 (i64 cell_info_buffer_sz)

        GL.UseProgram pg-supershader
        GL.BindBuffer GL.DISPATCH_INDIRECT_BUFFER compute_cmd_buffers

        local idx = 0
        local level = 0
        inline print-in-count (i)
            let buf = (cell_info_buffers @ i)
            let ptr =
                GL.MapNamedBufferRange buf 0 (sizeof u32)
                    GL.MAP_READ_BIT
            let ptr = (bitcast ptr (pointer CellValsInfo))
            print ptr.count
            GL.UnmapNamedBuffer buf

        inline init-voxels (l)
            level = l
            let i0 = (deref idx)
            idx = ((idx + 1) & 1)
            let i1 = (deref idx)
            let level = (deref level)
            GL.Uniform u-program ProgramVoxelizeInit
            GL.Uniform u-level level
            bind-read-buffer i0
            bind-write-buffer i1
            GL.DispatchCompute ((((1 << level) ** 3) // THREADSIZE) as u32) 1 1
            GL.MemoryBarrier GL.SHADER_STORAGE_BARRIER_BIT

        inline refine-voxels ()
            let i0 = (deref idx)
            idx = ((idx + 1) & 1)
            let i1 = (deref idx)
            level = level + 1
            let level = (deref level)
            GL.UseProgram pg-setup-compute
            GL.Uniform u-divisor THREADSIZE
            bind-read-buffer i0
            bind-ssbo compute_cmd_buffers buf-compute-cmd none 0
            GL.DispatchCompute 1 1 1
            GL.MemoryBarrier GL.COMMAND_BARRIER_BIT

            GL.UseProgram pg-supershader
            GL.Uniform u-program ProgramVoxelize
            GL.Uniform u-level level
            bind-read-buffer i0
            bind-write-buffer i1
            GL.DispatchComputeIndirect 0
            GL.MemoryBarrier GL.SHADER_STORAGE_BARRIER_BIT

        inline finalize-voxels ()
            let i0 = (deref idx)
            idx = ((idx + 1) & 1)
            let i1 = (deref idx)
            level = level + 1
            let level = (deref level)
            GL.UseProgram pg-setup-compute
            GL.Uniform u-divisor THREADSIZE
            #GL.Uniform u-divisor THREADSIZE
            bind-read-buffer i0
            bind-ssbo compute_cmd_buffers buf-compute-cmd none 0
            GL.DispatchCompute 1 1 1
            GL.MemoryBarrier GL.COMMAND_BARRIER_BIT

            GL.UseProgram pg-simplify
            #GL.Uniform u-program ProgramSimplify
            GL.Uniform u-level level
            bind-read-buffer i0
            bind-write-buffer i1
            GL.BindImageTexture IMAGE_TARGET_ATLAS coeff-atlas 0 GL.TRUE 0
                GL.WRITE_ONLY
                static-if USE_PACKING GL.RGBA8_SNORM
                else GL.RGBA32F
            GL.BindBufferRange GL.SHADER_STORAGE_BUFFER BINDING_BUF_VERTEX_ATTR1_OUT
                    \ vertex_buffer 0:i64 (i64 vertex_buffer_sz)
            GL.DispatchComputeIndirect 0
            #GL.MemoryBarrier GL.SHADER_STORAGE_BARRIER_BIT
            GL.MemoryBarrier (GL.ALL_BARRIER_BITS as u32)

        inline draw-surface ()
            #print-in-count (deref idx)
            GL.MemoryBarrier (GL.ALL_BARRIER_BITS as u32)
            GL.BindBuffer GL.DRAW_INDIRECT_BUFFER draw_cmd_buffers
            GL.UseProgram pg-setup-draw
            bind-read-buffer (deref idx)
            bind-ssbo draw_cmd_buffers buf-draw-cmd none 0
            GL.DispatchCompute 1 1 1
            GL.MemoryBarrier GL.COMMAND_BARRIER_BIT
            do
                GL.BindFramebuffer GL.FRAMEBUFFER fb-scene
                GL.Viewport 0 0 (i32 size.x) (i32 size.y)
                GL.ClearColor 0 0 0 0
                GL.DepthFunc GL.GREATER
                GL.ClearDepthf 0
                GL.DepthRangef -1 1
                GL.Enable GL.CULL_FACE
                GL.CullFace GL.BACK
                GL.Enable GL.DEPTH_TEST
                GL.Clear
                    |
                        GL.COLOR_BUFFER_BIT
                        GL.DEPTH_BUFFER_BIT
                        GL.STENCIL_BUFFER_BIT

                GL.UseProgram pg-rasterize
                GL.BindTextureUnit 1 coeff-atlas
                GL.Uniform smp-atlas 1
                bind-read-buffer (deref idx)
                GL.BindBufferRange GL.SHADER_STORAGE_BUFFER BINDING_BUF_VERTEX_ATTR1_IN
                        \ vertex_buffer 0:i64 (i64 vertex_buffer_sz)
                GL.Uniform u-level (deref level)
                GL.BindVertexArray vao-empty
                GL.DrawArraysIndirect GL.POINTS null

                GL.Disable GL.BLEND
                GL.Disable GL.DEPTH_TEST
                GL.Disable GL.CULL_FACE
                GL.BindFramebuffer GL.FRAMEBUFFER 0

        init-voxels 5
        refine-voxels;
        #refine-voxels;
        #refine-voxels;
        finalize-voxels;
        draw-surface;

    _ per-frame-setup shader

fn program ()
    render-fragment-shader main
        #debug = true
        size = (ivec2 512)


static-if true
    program;
else
    define f
        compile
            typify program
            'O3

    f;