Improve mandelbort example (#308)

This commit is contained in:
Max Graey
2019-01-09 18:26:31 +02:00
committed by Daniel Wirtz
parent 2ec89ee669
commit d82995c686
8 changed files with 861 additions and 353 deletions

View File

@ -5,39 +5,47 @@ const NUM_COLORS = 2048;
/** Computes a single line in the rectangle `width` x `height`. */
export function computeLine(y: u32, width: u32, height: u32, limit: u32): void {
var translateX = width / 1.6;
var translateY = height / 2.0;
var scale = 10.0 / min(3 * width, 4 * height);
var imaginary = (y - translateY) * scale;
var translateX = width * (1.0 / 1.6);
var translateY = height * (1.0 / 2.0);
var scale = 10.0 / min(3 * width, 4 * height);
var imaginary = (y - translateY) * scale;
var realOffset = translateX * scale;
var stride = (y * width) << 1;
var invLimit = 1.0 / limit;
var minIterations = min(8, limit);
for (let x: u32 = 0; x < width; ++x) {
let real = (x - translateX) * scale;
let real = x * scale - realOffset;
// Iterate until either the escape radius or iteration limit is exceeded
let ix = 0.0, iy = 0.0, ixSq: f64, iySq: f64;
let iteration: u32 = 0;
while ((ixSq = ix * ix) + (iySq = iy * iy) <= 4.0) {
let ixNew = ixSq - iySq + real;
iy = 2.0 * ix * iy + imaginary;
ix = ixNew;
ix = ixSq - iySq + real;
if (iteration >= limit) break;
++iteration;
}
// Do a few extra iterations for quick escapes to reduce error margin
for (let minIterations = min(8, limit); iteration < minIterations; ++iteration) {
while (iteration < minIterations) {
let ixNew = ix * ix - iy * iy + real;
iy = 2.0 * ix * iy + imaginary;
ix = ixNew;
++iteration;
}
// Iteration count is a discrete value in the range [0, limit] here, but we'd like it to be
// normalized in the range [0, 2047] so it maps to the gradient computed in JS.
// see also: http://linas.org/art-gallery/escape/escape.html
let frac = Math.log(Math.log(Math.sqrt(ix * ix + iy * iy))) / Math.LN2;
let icol = isFinite(frac)
? <u32>((NUM_COLORS - 1) * clamp((iteration + 1 - frac) / limit, 0.0, 1.0))
: NUM_COLORS - 1;
store<u16>((y * width + x) << 1, icol);
let col = NUM_COLORS - 1;
let sqd = ix * ix + iy * iy;
if (sqd > 1.0) {
let frac = Math.log2(0.5 * Math.log(sqd));
col = <u32>((NUM_COLORS - 1) * clamp((iteration + 1 - frac) * invLimit, 0.0, 1.0));
}
store<u16>(stride + (x << 1), col);
}
}

View File

@ -3,9 +3,8 @@
(type $FF (func (param f64) (result f64)))
(type $v (func))
(import "env" "memory" (memory $0 0))
(import "Math" "LN2" (global $~lib/bindings/Math/LN2 f64))
(import "Math" "sqrt" (func $~lib/bindings/Math/sqrt (param f64) (result f64)))
(import "Math" "log" (func $~lib/bindings/Math/log (param f64) (result f64)))
(import "Math" "log2" (func $~lib/bindings/Math/log2 (param f64) (result f64)))
(table $0 1 anyfunc)
(elem (i32.const 0) $null)
(export "memory" (memory $0))
@ -21,15 +20,13 @@
(local $10 f64)
(local $11 f64)
(local $12 f64)
get_local $1
f64.convert_u/i32
tee_local $6
f64.const 1.6
f64.div
set_local $12
(local $13 f64)
(local $14 f64)
f64.const 10
f64.const 3
get_local $6
get_local $1
f64.convert_u/i32
tee_local $8
f64.mul
f64.const 4
get_local $2
@ -42,12 +39,34 @@
get_local $0
f64.convert_u/i32
get_local $4
f64.const 2
f64.div
f64.const 0.5
f64.mul
f64.sub
get_local $9
f64.mul
set_local $10
get_local $8
f64.const 0.625
f64.mul
get_local $9
f64.mul
set_local $12
get_local $0
get_local $1
i32.mul
i32.const 1
i32.shl
set_local $0
f64.const 1
get_local $3
f64.convert_u/i32
tee_local $6
f64.div
set_local $13
f64.const 8
get_local $6
f64.min
set_local $8
loop $repeat|0
get_local $7
get_local $1
@ -55,10 +74,10 @@
if
get_local $7
f64.convert_u/i32
get_local $12
f64.sub
get_local $9
f64.mul
get_local $12
f64.sub
set_local $11
f64.const 0
set_local $4
@ -70,11 +89,11 @@
get_local $4
get_local $4
f64.mul
tee_local $6
tee_local $14
get_local $5
get_local $5
f64.mul
tee_local $8
tee_local $6
f64.add
f64.const 4
f64.le
@ -88,8 +107,8 @@
get_local $10
f64.add
set_local $5
get_local $14
get_local $6
get_local $8
f64.sub
get_local $11
f64.add
@ -106,15 +125,10 @@
end
end
end
f64.const 8
get_local $3
f64.convert_u/i32
f64.min
set_local $6
loop $repeat|2
loop $continue|2
get_local $2
f64.convert_u/i32
get_local $6
get_local $8
f64.lt
if
get_local $4
@ -126,7 +140,7 @@
f64.sub
get_local $11
f64.add
set_local $8
set_local $6
f64.const 2
get_local $4
f64.mul
@ -135,22 +149,20 @@
get_local $10
f64.add
set_local $5
get_local $8
get_local $6
set_local $4
get_local $2
i32.const 1
i32.add
set_local $2
br $repeat|2
br $continue|2
end
end
get_local $0
get_local $1
i32.mul
get_local $7
i32.add
i32.const 1
i32.shl
get_local $0
i32.add
get_local $4
get_local $4
f64.mul
@ -158,27 +170,23 @@
get_local $5
f64.mul
f64.add
call $~lib/bindings/Math/sqrt
call $~lib/bindings/Math/log
call $~lib/bindings/Math/log
get_global $~lib/bindings/Math/LN2
f64.div
tee_local $6
get_local $6
f64.sub
f64.const 0
f64.eq
f64.const 1
f64.gt
if (result i32)
f64.const 2047
get_local $2
i32.const 1
i32.add
f64.convert_u/i32
f64.const 0.5
get_local $6
call $~lib/bindings/Math/log
f64.mul
call $~lib/bindings/Math/log2
f64.sub
get_local $3
f64.convert_u/i32
f64.div
get_local $13
f64.mul
f64.const 0
f64.max
f64.const 1

View File

@ -1,13 +1,11 @@
(module
(type $iiiiv (func (param i32 i32 i32 i32)))
(type $FF (func (param f64) (result f64)))
(type $Fi (func (param f64) (result i32)))
(type $FFFF (func (param f64 f64 f64) (result f64)))
(type $v (func))
(import "env" "memory" (memory $0 0))
(import "Math" "LN2" (global $~lib/bindings/Math/LN2 f64))
(import "Math" "sqrt" (func $~lib/bindings/Math/sqrt (param f64) (result f64)))
(import "Math" "log" (func $~lib/bindings/Math/log (param f64) (result f64)))
(import "Math" "log2" (func $~lib/bindings/Math/log2 (param f64) (result f64)))
(table $0 1 anyfunc)
(elem (i32.const 0) $null)
(global $assembly/index/NUM_COLORS i32 (i32.const 2048))
@ -15,44 +13,45 @@
(export "memory" (memory $0))
(export "table" (table $0))
(export "computeLine" (func $assembly/index/computeLine))
(func $~lib/builtins/isFinite<f64> (; 2 ;) (type $Fi) (param $0 f64) (result i32)
get_local $0
get_local $0
f64.sub
f64.const 0
f64.eq
)
(func $assembly/index/clamp<f64> (; 3 ;) (type $FFFF) (param $0 f64) (param $1 f64) (param $2 f64) (result f64)
(func $assembly/index/clamp<f64> (; 2 ;) (type $FFFF) (param $0 f64) (param $1 f64) (param $2 f64) (result f64)
get_local $0
get_local $1
f64.max
get_local $2
f64.min
)
(func $assembly/index/computeLine (; 4 ;) (type $iiiiv) (param $0 i32) (param $1 i32) (param $2 i32) (param $3 i32)
(func $assembly/index/computeLine (; 3 ;) (type $iiiiv) (param $0 i32) (param $1 i32) (param $2 i32) (param $3 i32)
(local $4 f64)
(local $5 f64)
(local $6 f64)
(local $7 f64)
(local $8 i32)
(local $9 f64)
(local $8 f64)
(local $9 i32)
(local $10 f64)
(local $11 f64)
(local $12 f64)
(local $12 i32)
(local $13 f64)
(local $14 i32)
(local $14 f64)
(local $15 f64)
(local $16 f64)
(local $17 i32)
(local $17 f64)
(local $18 i32)
(local $19 f64)
(local $20 i32)
(local $21 f64)
get_local $1
f64.convert_u/i32
f64.const 1
f64.const 1.6
f64.div
f64.mul
set_local $4
get_local $2
f64.convert_u/i32
f64.const 1
f64.const 2
f64.div
f64.mul
set_local $5
f64.const 10
f64.const 3
@ -73,179 +72,189 @@
get_local $6
f64.mul
set_local $7
get_local $4
get_local $6
f64.mul
set_local $8
get_local $0
get_local $1
i32.mul
i32.const 1
i32.shl
set_local $9
f64.const 1
get_local $3
f64.convert_u/i32
f64.div
set_local $10
f64.const 8
get_local $3
f64.convert_u/i32
f64.min
set_local $11
block $break|0
i32.const 0
set_local $8
set_local $12
loop $repeat|0
get_local $8
get_local $12
get_local $1
i32.lt_u
i32.eqz
br_if $break|0
block
get_local $8
get_local $12
f64.convert_u/i32
get_local $4
f64.sub
get_local $6
f64.mul
set_local $9
get_local $8
f64.sub
set_local $13
f64.const 0
set_local $10
f64.const 0
set_local $11
i32.const 0
set_local $14
f64.const 0
set_local $15
i32.const 0
set_local $18
block $break|1
loop $continue|1
get_local $10
get_local $10
get_local $14
get_local $14
f64.mul
tee_local $12
get_local $11
get_local $11
tee_local $16
get_local $15
get_local $15
f64.mul
tee_local $13
tee_local $17
f64.add
f64.const 4
f64.le
if
block
get_local $12
get_local $13
f64.sub
get_local $9
f64.add
set_local $15
f64.const 2
get_local $10
get_local $14
f64.mul
get_local $11
get_local $15
f64.mul
get_local $7
f64.add
set_local $11
get_local $15
set_local $10
get_local $14
set_local $15
get_local $16
get_local $17
f64.sub
get_local $13
f64.add
set_local $14
get_local $18
get_local $3
i32.ge_u
if
br $break|1
end
get_local $14
get_local $18
i32.const 1
i32.add
set_local $14
set_local $18
end
br $continue|1
end
end
end
block $break|2
f64.const 8
get_local $3
f64.convert_u/i32
f64.min
set_local $15
loop $repeat|2
get_local $14
loop $continue|2
get_local $18
f64.convert_u/i32
get_local $15
get_local $11
f64.lt
i32.eqz
br_if $break|2
block
get_local $10
get_local $10
f64.mul
get_local $11
get_local $11
f64.mul
f64.sub
get_local $9
f64.add
set_local $16
f64.const 2
get_local $10
f64.mul
get_local $11
f64.mul
get_local $7
f64.add
set_local $11
get_local $16
set_local $10
if
block
get_local $14
get_local $14
f64.mul
get_local $15
get_local $15
f64.mul
f64.sub
get_local $13
f64.add
set_local $19
f64.const 2
get_local $14
f64.mul
get_local $15
f64.mul
get_local $7
f64.add
set_local $15
get_local $19
set_local $14
get_local $18
i32.const 1
i32.add
set_local $18
end
br $continue|2
end
get_local $14
i32.const 1
i32.add
set_local $14
br $repeat|2
unreachable
end
unreachable
end
get_local $10
get_local $10
get_global $assembly/index/NUM_COLORS
i32.const 1
i32.sub
set_local $20
get_local $14
get_local $14
f64.mul
get_local $11
get_local $11
get_local $15
get_local $15
f64.mul
f64.add
call $~lib/bindings/Math/sqrt
call $~lib/bindings/Math/log
call $~lib/bindings/Math/log
get_global $~lib/bindings/Math/LN2
f64.div
set_local $15
get_local $15
call $~lib/builtins/isFinite<f64>
if (result i32)
set_local $19
get_local $19
f64.const 1
f64.gt
if
f64.const 0.5
get_local $19
call $~lib/bindings/Math/log
f64.mul
call $~lib/bindings/Math/log2
set_local $21
get_global $assembly/index/NUM_COLORS
i32.const 1
i32.sub
f64.convert_s/i32
get_local $14
get_local $18
i32.const 1
i32.add
f64.convert_u/i32
get_local $15
get_local $21
f64.sub
get_local $3
f64.convert_u/i32
f64.div
get_local $10
f64.mul
f64.const 0
f64.const 1
call $assembly/index/clamp<f64>
f64.mul
i32.trunc_u/f64
else
get_global $assembly/index/NUM_COLORS
i32.const 1
i32.sub
set_local $20
end
set_local $17
get_local $0
get_local $1
i32.mul
get_local $8
i32.add
get_local $9
get_local $12
i32.const 1
i32.shl
get_local $17
i32.add
get_local $20
i32.store16
end
get_local $8
get_local $12
i32.const 1
i32.add
set_local $8
set_local $12
br $repeat|0
unreachable
end
unreachable
end
)
(func $null (; 5 ;) (type $v)
(func $null (; 4 ;) (type $v)
)
)

View File

@ -30,14 +30,19 @@ var ctx = cnv.getContext("2d");
var bcr = cnv.getBoundingClientRect();
// Compute the size of the viewport
var width = bcr.width | 0;
var width = bcr.width | 0;
var height = bcr.height | 0;
var ratio = window.devicePixelRatio || 1;
width *= ratio;
height *= ratio;
var size = width * height;
var byteSize = size << 1; // discrete color indices in range [0, 2047] (here: 2b per pixel)
cnv.width = width;
cnv.width = width;
cnv.height = height;
ctx.scale(ratio, ratio);
// Compute the size of and instantiate the module's memory
var memory = new WebAssembly.Memory({ initial: ((byteSize + 0xffff) & ~0xffff) >>> 16 });
var mem = new Uint16Array(memory.buffer);
@ -48,7 +53,7 @@ var argb = new Uint32Array(imageData.data.buffer);
fetch("build/optimized.wasm")
.then(response => response.arrayBuffer())
.then(buffer => WebAssembly.instantiate(buffer, {
env: { memory: memory },
env: { memory },
Math
}))
.then(module => {
@ -56,7 +61,9 @@ fetch("build/optimized.wasm")
var computeLine = exports.computeLine;
var updateLine = function(y) {
var yx = y * width;
for (let x = 0; x < width; ++x) argb[yx + x] = colors[mem[yx + x]];
for (let x = 0; x < width; ++x) {
argb[yx + x] = colors[mem[yx + x]];
}
};
// Compute an initial balanced version of the set.