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Proof-of-concept OIT

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shylie 2025-08-06 13:14:35 -04:00
parent 58656211e5
commit 2af1acf9a9
6 changed files with 780 additions and 38 deletions
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3
examples/CMakeLists.txt
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cmake_minimum_required(VERSION 3.21)
function(add_example name)
add_executable("example-${name}" ${name}.cpp)
add_executable("example-${name}" ${name}.cpp simplexnoise1234.cpp)
target_include_directories("example-${name}" PUBLIC .)
target_link_libraries("example-${name}" PUBLIC sprstk)
endfunction()

101
examples/basic.cpp
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#include <sprstk/sprstk.h>
#include <cstdlib>
#include <simplexnoise1234.h>
#include <cmath>
namespace
{
constexpr int SIZE = 256;
double octaves(SimplexNoise1234& simplex, double x, double y, int layers, double persistence, double frequency)
{
double ampl = 1;
double maxval = 0;
double val = 0;
for (int i = 0; i < layers; i++)
{
val += simplex.noise(x * frequency, y * frequency) * ampl;
maxval += ampl;
ampl *= persistence;
frequency *= 2;
}
return val / maxval;
}
uint8_t data[SIZE * SIZE];
double ease(double n)
{
return pow(n, 1.5);
}
uint32_t color(uint8_t r, uint8_t g, uint8_t b, uint8_t a)
{
return (r << 24) | (g << 16) | (b << 8) | a;
}
int pick_pal(uint8_t height)
{
if (height > 20) { return 0; }
if (height > 8) { return 1; }
return 2;
}
void init(sprstk* instance, void* userdata)
{
sprstk_palette pal = {};
for (int i = 0; i < 28; i++)
for (int i = 0; i < 24; i++)
{
pal.colors[i] = 0x7F3F0040;
uint8_t val = 0x33 / (12 - i / 2.0f) + 0x33;
pal.colors[i] = color(val, val, val, 0x7F);
}
for (int i = 28; i < 32; i++)
for (int i = 24; i < 32; i++)
{
pal.colors[i] = 0x00FF0040;
uint8_t val = 0x55 / (16 - i / 2.0f) + 0xAA;
pal.colors[i] = color(val, val, val, 0x7F);
}
sprstk_set_palette(instance, 0, &pal);
for (int i = 0; i < 16; i++)
{
pal.colors[i] = color(0x70 / (5.0f - i / 4.0f), 0x35 / (5.0f - i / 4.0f), 0, 0x7F);
}
for (int i = 16; i < 32; i++)
{
pal.colors[i] = color(0x05 / (8.5f - i / 2.5f) + 0x15, 0x40 / (8.5f - i / 2.5f) + 0x0, 0, 0x7F);
}
sprstk_set_palette(instance, 1, &pal);
for (int i = 0; i < 8; i++)
{
pal.colors[i] = color(0x20 / (8 - i) + 0x20, 0x40 / (8 - i) + 0x40, 0x90 / (8 - i) + 0x40, 0x7F);
}
sprstk_set_palette(instance, 2, &pal);
sprstk_set_scale(instance, 0.4f);
SimplexNoise1234 simplex;
for (int i = 0; i < SIZE; i++)
{
for (int j = 0; j < SIZE; j++)
{
double value = octaves(simplex, i, j, 6, 0.4, 1.0 / 128.0);
data[i + j * SIZE] = 28 * ease((value + 1) / 2) + 3;
}
}
for (int i = 0; i < SIZE; i++)
{
for (int j = 0; j < SIZE; j++)
{
sprstk_put(instance, i - SIZE / 2, j - SIZE / 2, data[i + SIZE * j], pick_pal(data[i + SIZE * j]));
}
}
}
void update(sprstk* instance, float dt, float* userdata)
{
*userdata += dt / 2;
sprstk_set_angle(instance, *userdata);
for (int i = -512; i < 512; i++)
{
for (int j = -512; j < 512; j++)
{
sprstk_put(instance, i, j, 31, 0);
}
}
}
}

470
examples/simplexnoise1234.cpp Normal file
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// SimplexNoise1234
// Copyright © 2003-2011, Stefan Gustavson
//
// Contact: stegu@itn.liu.se
//
// This library is public domain software, released by the author
// into the public domain in February 2011. You may do anything
// you like with it. You may even remove all attributions,
// but of course I'd appreciate it if you kept my name somewhere.
//
// This library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
// General Public License for more details.
// Modified by the LOVE Development Team to use double precision.
/** \file
\brief Implements the SimplexNoise1234 class for producing Perlin simplex noise.
\author Stefan Gustavson (stegu@itn.liu.se)
*/
/*
* This implementation is "Simplex Noise" as presented by
* Ken Perlin at a relatively obscure and not often cited course
* session "Real-Time Shading" at Siggraph 2001 (before real
* time shading actually took on), under the title "hardware noise".
* The 3D function is numerically equivalent to his Java reference
* code available in the PDF course notes, although I re-implemented
* it from scratch to get more readable code. The 1D, 2D and 4D cases
* were implemented from scratch by me from Ken Perlin's text.
*
* This is a highly reusable class. It has no dependencies
* on any other file, apart from its own header file.
*/
#include "simplexnoise1234.h"
#define FASTFLOOR(x) ( ((x)>0) ? ((int)x) : (((int)x)-1) )
//---------------------------------------------------------------------
// Static data
/*
* Permutation table. This is just a random jumble of all numbers 0-255,
* repeated twice to avoid wrapping the index at 255 for each lookup.
* This needs to be exactly the same for all instances on all platforms,
* so it's easiest to just keep it as static explicit data.
* This also removes the need for any initialisation of this class.
*
* Note that making this an int[] instead of a char[] might make the
* code run faster on platforms with a high penalty for unaligned single
* byte addressing. Intel x86 is generally single-byte-friendly, but
* some other CPUs are faster with 4-aligned reads.
* However, a char[] is smaller, which avoids cache trashing, and that
* is probably the most important aspect on most architectures.
* This array is accessed a *lot* by the noise functions.
* A vector-valued noise over 3D accesses it 96 times, and a
* float-valued 4D noise 64 times. We want this to fit in the cache!
*/
unsigned char SimplexNoise1234::perm[512] = {151,160,137,91,90,15,
131,13,201,95,96,53,194,233,7,225,140,36,103,30,69,142,8,99,37,240,21,10,23,
190, 6,148,247,120,234,75,0,26,197,62,94,252,219,203,117,35,11,32,57,177,33,
88,237,149,56,87,174,20,125,136,171,168, 68,175,74,165,71,134,139,48,27,166,
77,146,158,231,83,111,229,122,60,211,133,230,220,105,92,41,55,46,245,40,244,
102,143,54, 65,25,63,161, 1,216,80,73,209,76,132,187,208, 89,18,169,200,196,
135,130,116,188,159,86,164,100,109,198,173,186, 3,64,52,217,226,250,124,123,
5,202,38,147,118,126,255,82,85,212,207,206,59,227,47,16,58,17,182,189,28,42,
223,183,170,213,119,248,152, 2,44,154,163, 70,221,153,101,155,167, 43,172,9,
129,22,39,253, 19,98,108,110,79,113,224,232,178,185, 112,104,218,246,97,228,
251,34,242,193,238,210,144,12,191,179,162,241, 81,51,145,235,249,14,239,107,
49,192,214, 31,181,199,106,157,184, 84,204,176,115,121,50,45,127, 4,150,254,
138,236,205,93,222,114,67,29,24,72,243,141,128,195,78,66,215,61,156,180,
151,160,137,91,90,15,
131,13,201,95,96,53,194,233,7,225,140,36,103,30,69,142,8,99,37,240,21,10,23,
190, 6,148,247,120,234,75,0,26,197,62,94,252,219,203,117,35,11,32,57,177,33,
88,237,149,56,87,174,20,125,136,171,168, 68,175,74,165,71,134,139,48,27,166,
77,146,158,231,83,111,229,122,60,211,133,230,220,105,92,41,55,46,245,40,244,
102,143,54, 65,25,63,161, 1,216,80,73,209,76,132,187,208, 89,18,169,200,196,
135,130,116,188,159,86,164,100,109,198,173,186, 3,64,52,217,226,250,124,123,
5,202,38,147,118,126,255,82,85,212,207,206,59,227,47,16,58,17,182,189,28,42,
223,183,170,213,119,248,152, 2,44,154,163, 70,221,153,101,155,167, 43,172,9,
129,22,39,253, 19,98,108,110,79,113,224,232,178,185, 112,104,218,246,97,228,
251,34,242,193,238,210,144,12,191,179,162,241, 81,51,145,235,249,14,239,107,
49,192,214, 31,181,199,106,157,184, 84,204,176,115,121,50,45,127, 4,150,254,
138,236,205,93,222,114,67,29,24,72,243,141,128,195,78,66,215,61,156,180
};
//---------------------------------------------------------------------
/*
* Helper functions to compute gradients-dot-residualvectors (1D to 4D)
* Note that these generate gradients of more than unit length. To make
* a close match with the value range of classic Perlin noise, the final
* noise values need to be rescaled to fit nicely within [-1,1].
* (The simplex noise functions as such also have different scaling.)
* Note also that these noise functions are the most practical and useful
* signed version of Perlin noise. To return values according to the
* RenderMan specification from the SL noise() and pnoise() functions,
* the noise values need to be scaled and offset to [0,1], like this:
* float SLnoise = (SimplexNoise1234::noise(x,y,z) + 1.0) * 0.5;
*/
double SimplexNoise1234::grad( int hash, double x ) {
int h = hash & 15;
double grad = 1.0 + (h & 7); // Gradient value 1.0, 2.0, ..., 8.0
if (h&8) grad = -grad; // Set a random sign for the gradient
return ( grad * x ); // Multiply the gradient with the distance
}
double SimplexNoise1234::grad( int hash, double x, double y ) {
int h = hash & 7; // Convert low 3 bits of hash code
double u = h<4 ? x : y; // into 8 simple gradient directions,
double v = h<4 ? y : x; // and compute the dot product with (x,y).
return ((h&1)? -u : u) + ((h&2)? -2.0*v : 2.0*v);
}
double SimplexNoise1234::grad( int hash, double x, double y , double z ) {
int h = hash & 15; // Convert low 4 bits of hash code into 12 simple
double u = h<8 ? x : y; // gradient directions, and compute dot product.
double v = h<4 ? y : h==12||h==14 ? x : z; // Fix repeats at h = 12 to 15
return ((h&1)? -u : u) + ((h&2)? -v : v);
}
double SimplexNoise1234::grad( int hash, double x, double y, double z, double t ) {
int h = hash & 31; // Convert low 5 bits of hash code into 32 simple
double u = h<24 ? x : y; // gradient directions, and compute dot product.
double v = h<16 ? y : z;
double w = h<8 ? z : t;
return ((h&1)? -u : u) + ((h&2)? -v : v) + ((h&4)? -w : w);
}
// A lookup table to traverse the simplex around a given point in 4D.
// Details can be found where this table is used, in the 4D noise method.
/* TODO: This should not be required, backport it from Bill's GLSL code! */
static unsigned char simplex[64][4] = {
{0,1,2,3},{0,1,3,2},{0,0,0,0},{0,2,3,1},{0,0,0,0},{0,0,0,0},{0,0,0,0},{1,2,3,0},
{0,2,1,3},{0,0,0,0},{0,3,1,2},{0,3,2,1},{0,0,0,0},{0,0,0,0},{0,0,0,0},{1,3,2,0},
{0,0,0,0},{0,0,0,0},{0,0,0,0},{0,0,0,0},{0,0,0,0},{0,0,0,0},{0,0,0,0},{0,0,0,0},
{1,2,0,3},{0,0,0,0},{1,3,0,2},{0,0,0,0},{0,0,0,0},{0,0,0,0},{2,3,0,1},{2,3,1,0},
{1,0,2,3},{1,0,3,2},{0,0,0,0},{0,0,0,0},{0,0,0,0},{2,0,3,1},{0,0,0,0},{2,1,3,0},
{0,0,0,0},{0,0,0,0},{0,0,0,0},{0,0,0,0},{0,0,0,0},{0,0,0,0},{0,0,0,0},{0,0,0,0},
{2,0,1,3},{0,0,0,0},{0,0,0,0},{0,0,0,0},{3,0,1,2},{3,0,2,1},{0,0,0,0},{3,1,2,0},
{2,1,0,3},{0,0,0,0},{0,0,0,0},{0,0,0,0},{3,1,0,2},{0,0,0,0},{3,2,0,1},{3,2,1,0}};
// 1D simplex noise
double SimplexNoise1234::noise(double x) {
int i0 = FASTFLOOR(x);
int i1 = i0 + 1;
double x0 = x - i0;
double x1 = x0 - 1.0;
double n0, n1;
double t0 = 1.0 - x0*x0;
t0 *= t0;
n0 = t0 * t0 * grad(perm[i0 & 0xff], x0);
double t1 = 1.0 - x1*x1;
t1 *= t1;
n1 = t1 * t1 * grad(perm[i1 & 0xff], x1);
// The maximum value of this noise is 8*(3/4)^4 = 2.53125
// A factor of 0.395 will scale to fit exactly within [-1,1]
return 0.395 * (n0 + n1);
}
// 2D simplex noise
double SimplexNoise1234::noise(double x, double y) {
#define F2 0.366025403 // F2 = 0.5*(sqrt(3.0)-1.0)
#define G2 0.211324865 // G2 = (3.0-Math.sqrt(3.0))/6.0
double n0, n1, n2; // Noise contributions from the three corners
// Skew the input space to determine which simplex cell we're in
double s = (x+y)*F2; // Hairy factor for 2D
double xs = x + s;
double ys = y + s;
int i = FASTFLOOR(xs);
int j = FASTFLOOR(ys);
double t = (i+j)*G2;
double X0 = i-t; // Unskew the cell origin back to (x,y) space
double Y0 = j-t;
double x0 = x-X0; // The x,y distances from the cell origin
double y0 = y-Y0;
// For the 2D case, the simplex shape is an equilateral triangle.
// Determine which simplex we are in.
int i1, j1; // Offsets for second (middle) corner of simplex in (i,j) coords
if(x0>y0) {i1=1; j1=0;} // lower triangle, XY order: (0,0)->(1,0)->(1,1)
else {i1=0; j1=1;} // upper triangle, YX order: (0,0)->(0,1)->(1,1)
// A step of (1,0) in (i,j) means a step of (1-c,-c) in (x,y), and
// a step of (0,1) in (i,j) means a step of (-c,1-c) in (x,y), where
// c = (3-sqrt(3))/6
double x1 = x0 - i1 + G2; // Offsets for middle corner in (x,y) unskewed coords
double y1 = y0 - j1 + G2;
double x2 = x0 - 1.0 + 2.0 * G2; // Offsets for last corner in (x,y) unskewed coords
double y2 = y0 - 1.0 + 2.0 * G2;
// Wrap the integer indices at 256, to avoid indexing perm[] out of bounds
int ii = i & 0xff;
int jj = j & 0xff;
// Calculate the contribution from the three corners
double t0 = 0.5 - x0*x0-y0*y0;
if(t0 < 0.0) n0 = 0.0;
else {
t0 *= t0;
n0 = t0 * t0 * grad(perm[ii+perm[jj]], x0, y0);
}
double t1 = 0.5 - x1*x1-y1*y1;
if(t1 < 0.0) n1 = 0.0;
else {
t1 *= t1;
n1 = t1 * t1 * grad(perm[ii+i1+perm[jj+j1]], x1, y1);
}
double t2 = 0.5 - x2*x2-y2*y2;
if(t2 < 0.0) n2 = 0.0;
else {
t2 *= t2;
n2 = t2 * t2 * grad(perm[ii+1+perm[jj+1]], x2, y2);
}
// Add contributions from each corner to get the final noise value.
// The result is scaled to return values in the interval [-1,1].
return 45.23 * (n0 + n1 + n2); // TODO: The scale factor is preliminary!
}
// 3D simplex noise
double SimplexNoise1234::noise(double x, double y, double z) {
// Simple skewing factors for the 3D case
#define F3 0.333333333
#define G3 0.166666667
double n0, n1, n2, n3; // Noise contributions from the four corners
// Skew the input space to determine which simplex cell we're in
double s = (x+y+z)*F3; // Very nice and simple skew factor for 3D
double xs = x+s;
double ys = y+s;
double zs = z+s;
int i = FASTFLOOR(xs);
int j = FASTFLOOR(ys);
int k = FASTFLOOR(zs);
double t = (float)(i+j+k)*G3;
double X0 = i-t; // Unskew the cell origin back to (x,y,z) space
double Y0 = j-t;
double Z0 = k-t;
double x0 = x-X0; // The x,y,z distances from the cell origin
double y0 = y-Y0;
double z0 = z-Z0;
// For the 3D case, the simplex shape is a slightly irregular tetrahedron.
// Determine which simplex we are in.
int i1, j1, k1; // Offsets for second corner of simplex in (i,j,k) coords
int i2, j2, k2; // Offsets for third corner of simplex in (i,j,k) coords
/* This code would benefit from a backport from the GLSL version! */
if(x0>=y0) {
if(y0>=z0)
{ i1=1; j1=0; k1=0; i2=1; j2=1; k2=0; } // X Y Z order
else if(x0>=z0) { i1=1; j1=0; k1=0; i2=1; j2=0; k2=1; } // X Z Y order
else { i1=0; j1=0; k1=1; i2=1; j2=0; k2=1; } // Z X Y order
}
else { // x0<y0
if(y0<z0) { i1=0; j1=0; k1=1; i2=0; j2=1; k2=1; } // Z Y X order
else if(x0<z0) { i1=0; j1=1; k1=0; i2=0; j2=1; k2=1; } // Y Z X order
else { i1=0; j1=1; k1=0; i2=1; j2=1; k2=0; } // Y X Z order
}
// A step of (1,0,0) in (i,j,k) means a step of (1-c,-c,-c) in (x,y,z),
// a step of (0,1,0) in (i,j,k) means a step of (-c,1-c,-c) in (x,y,z), and
// a step of (0,0,1) in (i,j,k) means a step of (-c,-c,1-c) in (x,y,z), where
// c = 1/6.
double x1 = x0 - i1 + G3; // Offsets for second corner in (x,y,z) coords
double y1 = y0 - j1 + G3;
double z1 = z0 - k1 + G3;
double x2 = x0 - i2 + 2.0f*G3; // Offsets for third corner in (x,y,z) coords
double y2 = y0 - j2 + 2.0f*G3;
double z2 = z0 - k2 + 2.0f*G3;
double x3 = x0 - 1.0f + 3.0f*G3; // Offsets for last corner in (x,y,z) coords
double y3 = y0 - 1.0f + 3.0f*G3;
double z3 = z0 - 1.0f + 3.0f*G3;
// Wrap the integer indices at 256, to avoid indexing perm[] out of bounds
int ii = i & 0xff;
int jj = j & 0xff;
int kk = k & 0xff;
// Calculate the contribution from the four corners
double t0 = 0.6f - x0*x0 - y0*y0 - z0*z0;
if(t0 < 0.0f) n0 = 0.0f;
else {
t0 *= t0;
n0 = t0 * t0 * grad(perm[ii+perm[jj+perm[kk]]], x0, y0, z0);
}
double t1 = 0.6f - x1*x1 - y1*y1 - z1*z1;
if(t1 < 0.0f) n1 = 0.0f;
else {
t1 *= t1;
n1 = t1 * t1 * grad(perm[ii+i1+perm[jj+j1+perm[kk+k1]]], x1, y1, z1);
}
double t2 = 0.6f - x2*x2 - y2*y2 - z2*z2;
if(t2 < 0.0f) n2 = 0.0f;
else {
t2 *= t2;
n2 = t2 * t2 * grad(perm[ii+i2+perm[jj+j2+perm[kk+k2]]], x2, y2, z2);
}
double t3 = 0.6f - x3*x3 - y3*y3 - z3*z3;
if(t3<0.0f) n3 = 0.0f;
else {
t3 *= t3;
n3 = t3 * t3 * grad(perm[ii+1+perm[jj+1+perm[kk+1]]], x3, y3, z3);
}
// Add contributions from each corner to get the final noise value.
// The result is scaled to stay just inside [-1,1]
return 32.74 * (n0 + n1 + n2 + n3); // TODO: The scale factor is preliminary!
}
// 4D simplex noise
double SimplexNoise1234::noise(double x, double y, double z, double w) {
// The skewing and unskewing factors are hairy again for the 4D case
#define F4 0.309016994 // F4 = (Math.sqrt(5.0)-1.0)/4.0
#define G4 0.138196601 // G4 = (5.0-Math.sqrt(5.0))/20.0
double n0, n1, n2, n3, n4; // Noise contributions from the five corners
// Skew the (x,y,z,w) space to determine which cell of 24 simplices we're in
double s = (x + y + z + w) * F4; // Factor for 4D skewing
double xs = x + s;
double ys = y + s;
double zs = z + s;
double ws = w + s;
int i = FASTFLOOR(xs);
int j = FASTFLOOR(ys);
int k = FASTFLOOR(zs);
int l = FASTFLOOR(ws);
double t = (i + j + k + l) * G4; // Factor for 4D unskewing
double X0 = i - t; // Unskew the cell origin back to (x,y,z,w) space
double Y0 = j - t;
double Z0 = k - t;
double W0 = l - t;
double x0 = x - X0; // The x,y,z,w distances from the cell origin
double y0 = y - Y0;
double z0 = z - Z0;
double w0 = w - W0;
// For the 4D case, the simplex is a 4D shape I won't even try to describe.
// To find out which of the 24 possible simplices we're in, we need to
// determine the magnitude ordering of x0, y0, z0 and w0.
// The method below is a good way of finding the ordering of x,y,z,w and
// then find the correct traversal order for the simplex we’re in.
// First, six pair-wise comparisons are performed between each possible pair
// of the four coordinates, and the results are used to add up binary bits
// for an integer index.
int c1 = (x0 > y0) ? 32 : 0;
int c2 = (x0 > z0) ? 16 : 0;
int c3 = (y0 > z0) ? 8 : 0;
int c4 = (x0 > w0) ? 4 : 0;
int c5 = (y0 > w0) ? 2 : 0;
int c6 = (z0 > w0) ? 1 : 0;
int c = c1 + c2 + c3 + c4 + c5 + c6;
int i1, j1, k1, l1; // The integer offsets for the second simplex corner
int i2, j2, k2, l2; // The integer offsets for the third simplex corner
int i3, j3, k3, l3; // The integer offsets for the fourth simplex corner
// simplex[c] is a 4-vector with the numbers 0, 1, 2 and 3 in some order.
// Many values of c will never occur, since e.g. x>y>z>w makes x<z, y<w and x<w
// impossible. Only the 24 indices which have non-zero entries make any sense.
// We use a thresholding to set the coordinates in turn from the largest magnitude.
// The number 3 in the "simplex" array is at the position of the largest coordinate.
i1 = simplex[c][0]>=3 ? 1 : 0;
j1 = simplex[c][1]>=3 ? 1 : 0;
k1 = simplex[c][2]>=3 ? 1 : 0;
l1 = simplex[c][3]>=3 ? 1 : 0;
// The number 2 in the "simplex" array is at the second largest coordinate.
i2 = simplex[c][0]>=2 ? 1 : 0;
j2 = simplex[c][1]>=2 ? 1 : 0;
k2 = simplex[c][2]>=2 ? 1 : 0;
l2 = simplex[c][3]>=2 ? 1 : 0;
// The number 1 in the "simplex" array is at the second smallest coordinate.
i3 = simplex[c][0]>=1 ? 1 : 0;
j3 = simplex[c][1]>=1 ? 1 : 0;
k3 = simplex[c][2]>=1 ? 1 : 0;
l3 = simplex[c][3]>=1 ? 1 : 0;
// The fifth corner has all coordinate offsets = 1, so no need to look that up.
double x1 = x0 - i1 + G4; // Offsets for second corner in (x,y,z,w) coords
double y1 = y0 - j1 + G4;
double z1 = z0 - k1 + G4;
double w1 = w0 - l1 + G4;
double x2 = x0 - i2 + 2.0f*G4; // Offsets for third corner in (x,y,z,w) coords
double y2 = y0 - j2 + 2.0f*G4;
double z2 = z0 - k2 + 2.0f*G4;
double w2 = w0 - l2 + 2.0f*G4;
double x3 = x0 - i3 + 3.0f*G4; // Offsets for fourth corner in (x,y,z,w) coords
double y3 = y0 - j3 + 3.0f*G4;
double z3 = z0 - k3 + 3.0f*G4;
double w3 = w0 - l3 + 3.0f*G4;
double x4 = x0 - 1.0f + 4.0f*G4; // Offsets for last corner in (x,y,z,w) coords
double y4 = y0 - 1.0f + 4.0f*G4;
double z4 = z0 - 1.0f + 4.0f*G4;
double w4 = w0 - 1.0f + 4.0f*G4;
// Wrap the integer indices at 256, to avoid indexing perm[] out of bounds
int ii = i & 0xff;
int jj = j & 0xff;
int kk = k & 0xff;
int ll = l & 0xff;
// Calculate the contribution from the five corners
double t0 = 0.6f - x0*x0 - y0*y0 - z0*z0 - w0*w0;
if(t0 < 0.0f) n0 = 0.0f;
else {
t0 *= t0;
n0 = t0 * t0 * grad(perm[ii+perm[jj+perm[kk+perm[ll]]]], x0, y0, z0, w0);
}
double t1 = 0.6f - x1*x1 - y1*y1 - z1*z1 - w1*w1;
if(t1 < 0.0f) n1 = 0.0f;
else {
t1 *= t1;
n1 = t1 * t1 * grad(perm[ii+i1+perm[jj+j1+perm[kk+k1+perm[ll+l1]]]], x1, y1, z1, w1);
}
double t2 = 0.6f - x2*x2 - y2*y2 - z2*z2 - w2*w2;
if(t2 < 0.0f) n2 = 0.0f;
else {
t2 *= t2;
n2 = t2 * t2 * grad(perm[ii+i2+perm[jj+j2+perm[kk+k2+perm[ll+l2]]]], x2, y2, z2, w2);
}
double t3 = 0.6f - x3*x3 - y3*y3 - z3*z3 - w3*w3;
if(t3 < 0.0f) n3 = 0.0f;
else {
t3 *= t3;
n3 = t3 * t3 * grad(perm[ii+i3+perm[jj+j3+perm[kk+k3+perm[ll+l3]]]], x3, y3, z3, w3);
}
double t4 = 0.6f - x4*x4 - y4*y4 - z4*z4 - w4*w4;
if(t4 < 0.0f) n4 = 0.0f;
else {
t4 *= t4;
n4 = t4 * t4 * grad(perm[ii+1+perm[jj+1+perm[kk+1+perm[ll+1]]]], x4, y4, z4, w4);
}
// Sum up and scale the result to cover the range [-1,1]
return 27.3 * (n0 + n1 + n2 + n3 + n4); // TODO: The scale factor is preliminary!
}
//---------------------------------------------------------------------

48
examples/simplexnoise1234.h Normal file
View File

@ -0,0 +1,48 @@
// SimplexNoise1234
// Copyright © 2003-2011, Stefan Gustavson
//
// Contact: stegu@itn.liu.se
//
// This library is public domain software, released by the author
// into the public domain in February 2011. You may do anything
// you like with it. You may even remove all attributions,
// but of course I'd appreciate it if you kept my name somewhere.
//
// This library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
// General Public License for more details.
// Modified by the LOVE Development Team to use double precision.
/** \file
\brief Declares the SimplexNoise1234 class for producing Perlin simplex noise.
\author Stefan Gustavson (stegu@itn.liu.se)
*/
/*
* This is a clean, fast, modern and free Perlin Simplex noise class in C++.
* Being a stand-alone class with no external dependencies, it is
* highly reusable without source code modifications.
*/
class SimplexNoise1234 {
public:
SimplexNoise1234() {}
~SimplexNoise1234() {}
/** 1D and 2D float Perlin noise
*/
static double noise( double x );
static double noise( double x, double y );
static double noise( double x, double y, double z );
static double noise( double x, double y, double z, double w);
private:
static unsigned char perm[];
static double grad( int hash, double x );
static double grad( int hash, double x, double y );
static double grad( int hash, double x, double y, double z );
static double grad( int hash, double x, double y, double z, double t );
};

3
include/sprstk/sprstk.h
View File

@ -30,11 +30,14 @@ void sprstk_del(sprstk* instance);
void sprstk_run(sprstk* instance);
void sprstk_stop(sprstk* instance);
void sprstk_clear(sprstk* instance);
void sprstk_put(sprstk* instance, int x, int y, unsigned int layers, unsigned int palette_lookup);
void sprstk_putz(sprstk* instance, int x, int y, unsigned int layers, unsigned int palette_lookup, unsigned int z_offset);
void sprstk_set_palette(sprstk* instance, unsigned int index, const sprstk_palette* palette);
void sprstk_set_scale(sprstk* instance, float scale);
void sprstk_set_angle(sprstk* instance, float angle);
#ifdef __cplusplus

191
src/sprstk.cpp
View File

@ -7,6 +7,10 @@
#include <cmath>
#define OIT_LAYERS 1
#define _STRINGIFY(x) #x
#define STRINGIFY(x) _STRINGIFY(x)
const char* MESH_SHADER_CODE = R"(
#version 460
@ -17,11 +21,13 @@ layout (triangles, max_vertices = 128, max_primitives = 64) out;
layout (location = 0) out PerVertexData
{
flat uint layer;
vec4 color;
} v_out[];
layout (location = 1) uniform vec3 screen_size_and_pixel_scale;
layout (location = 2) uniform mat2 rotation_matrix;
layout (location = 2) uniform float scale;
layout (location = 3) uniform mat2 rotation_matrix;
struct TileInfo
{
@ -54,31 +60,37 @@ void main()
uint layer_count = bitfieldExtract(t_info.position, 20, 5);
vec2 positions[4] = { vec2(0, 0), vec2(1, 0), vec2(0, 1), vec2(1, 1) };
float minsize = min(screen_size_and_pixel_scale.x, screen_size_and_pixel_scale.y);
vec2 positions[4] = { vec2(-0.5, -0.5), vec2(0.5, -0.5), vec2(-0.5, 0.5), vec2(0.5, 0.5) };
for (uint i = 0; i < 4; i++)
{
positions[i] += stack_position;
positions[i] *= screen_size_and_pixel_scale.zz;
positions[i] /= vec2(min(screen_size_and_pixel_scale.x, screen_size_and_pixel_scale.y));
}
uint z_offset = bitfieldExtract(t_info.position, 25, 2);
uint palette_lookup = bitfieldExtract(t_info.position, 27, 5);
ColorInfo c_info = color_infos[palette_lookup];
float a = bitfieldExtract(c_info.color[gl_LocalInvocationID.x], 0, 8);
float b = bitfieldExtract(c_info.color[gl_LocalInvocationID.x], 8, 8);
float g = bitfieldExtract(c_info.color[gl_LocalInvocationID.x], 16, 8);
float r = bitfieldExtract(c_info.color[gl_LocalInvocationID.x], 24, 8);
uint c = c_info.color[gl_LocalInvocationID.x];
float a = bitfieldExtract(c, 0, 8);
float b = bitfieldExtract(c, 8, 8);
float g = bitfieldExtract(c, 16, 8);
float r = bitfieldExtract(c, 24, 8);
vec4 color = vec4(r, g, b, a) / vec4(256);
for (uint i = 4 * gl_LocalInvocationID.x; i < 4 * gl_LocalInvocationID.x + 4; i++)
{
vec4 position = vec4(rotation_matrix * positions[i % 4], float(4 * gl_LocalInvocationID.x + z_offset) / 128, 1);
position.y += 24 * position.z / screen_size_and_pixel_scale.z;
position.xy *= vec2(0.05);
position.xy /= screen_size_and_pixel_scale.xy;
position.xy *= scale;
position.y += 16 * gl_LocalInvocationID.x * scale / screen_size_and_pixel_scale.y;
gl_MeshVerticesNV[i].gl_Position = position;
v_out[i].color = vec4(r, g, b, a) / vec4(256, 256, 256, 256);
v_out[i].layer = 4 * gl_LocalInvocationID.x + z_offset;
v_out[i].color = color;
}
for (uint i = 6 * gl_LocalInvocationID.x; i < 6 * gl_LocalInvocationID.x + 6; i++)
@ -93,16 +105,75 @@ void main()
const char* FRAGMENT_SHADER_CODE = R"(
#version 460
#extension GL_NV_fragment_shader_interlock : enable
#extension GL_ARB_fragment_shader_interlock : enable
#if GL_NV_fragment_shader_interlock || GL_ARB_fragment_shader_interlock
layout (pixel_interlock_unordered) in;
#if GL_NV_fragment_shader_interlock
#define beginInvocationInterlock beginInvocationInterlockNV
#define endInvocationInterlock endInvocationInterlockNV
#else // GL_NV_fragment_shader_interlock
#define beginInvocationInterlock beginInvocationInterlockARB
#define endInvocationInterlock endInvocationInterlockARB
#endif // GL_NV_fragment_shader_interlock
#else // #if GL_NV_fragment_shader_interlock || GL_ARB_fragment_shader_interlock
#pragma error "fragment shader interlock is required"
#endif // #if GL_NV_fragment_shader_interlock || GL_ARB_fragment_shader_interlock
layout (location = 0) out vec4 FragColor;
layout (binding = 0, rgba8) uniform restrict coherent image3D ABuffer;
layout (binding = 1, r8ui) uniform restrict coherent uimage3D ZBuffer;
in PerVertexData
{
flat uint layer;
vec4 color;
} fragIn;
void main()
{
FragColor = fragIn.color;
vec4 color = fragIn.color;
uint z_current = fragIn.layer;
beginInvocationInterlock();
for (int i = 0; i < )" STRINGIFY(OIT_LAYERS) R"(; i++)
{
const ivec3 image_coord = ivec3(gl_FragCoord.xy, i);
const uint z_from_buffer = imageLoad(ZBuffer, image_coord).x;
if (z_current < z_from_buffer)
{
imageStore(ZBuffer, image_coord, uvec4(z_current, 0, 0, 0));
const vec4 temp_color = imageLoad(ABuffer, image_coord);
imageStore(ABuffer, image_coord, color);
z_current = z_from_buffer;
color = temp_color;
if (z_current == 0xFF) { break; }
}
}
endInvocationInterlock();
memoryBarrierImage();
color = vec4(0);
for (int i = 0; i < )" STRINGIFY(OIT_LAYERS) R"(; i++)
{
const ivec3 image_coord = ivec3(gl_FragCoord.xy, i);
const vec4 temp_color = imageLoad(ABuffer, image_coord);
color = vec4(temp_color.rgb * temp_color.a + color.rgb * (1 - temp_color.a), temp_color.a);
}
FragColor = color;
}
)";
@ -124,7 +195,9 @@ public:
callbacks(callbacks),
userdata(userdata),
should_stop(false),
prev_ticks(0)
prev_ticks(0),
prev_resized_ticks(0),
resized(false)
{
if (!callbacks.update)
{
@ -158,10 +231,8 @@ public:
if (e.type == SDL_EVENT_WINDOW_RESIZED)
{
int width, height;
SDL_GetWindowSizeInPixels(sdl.window, &width, &height);
glViewport(0, 0, width, height);
glProgramUniform3f(gl.program, 1, width, height, 8);
prev_resized_ticks = prev_ticks;
resized = true;
}
}
@ -169,11 +240,30 @@ public:
float dt = (current_ticks - prev_ticks) / 1000.0f;
prev_ticks = current_ticks;
gl.tile_count = 0;
if (resized && (current_ticks - prev_resized_ticks) / 1000.0f > 0.5f)
{
prev_resized_ticks = 0;
resized = false;
int width, height;
SDL_GetWindowSizeInPixels(sdl.window, &width, &height);
glViewport(0, 0, width, height);
glProgramUniform3f(gl.program, 1, width, height, 8);
create_buffers();
}
callbacks.update(this, dt, userdata);
glClearColor(0, 0, 0, 1);
glClear(GL_COLOR_BUFFER_BIT);
constexpr uint32_t color = 0;
glClearTexImage(gl.a_buffer, 0, GL_RGBA, GL_UNSIGNED_INT, &color);
constexpr uint8_t z = 0xFF;
glClearTexImage(gl.z_buffer, 0, GL_RED_INTEGER, GL_UNSIGNED_BYTE, &z);
int i;
for (i = 0; i < gl.tile_count; i += 65535)
{
@ -191,6 +281,11 @@ public:
should_stop = true;
}
void clear()
{
gl.tile_count = 0;
}
void put(int x, int y, unsigned int layers, unsigned int palette_lookup, unsigned int z_offset = 0)
{
x += 512;
@ -219,13 +314,18 @@ public:
gl.color_info_map[index] = *palette;
}
void set_scale(float scale)
{
glProgramUniform1f(gl.program, 2, scale);
}
void set_angle(float angle)
{
const float arr[4] = {
cosf(angle), -sinf(angle),
sinf(angle), cosf(angle)
};
glProgramUniformMatrix2fv(gl.program, 2, 1, false, arr);
glProgramUniformMatrix2fv(gl.program, 3, 1, false, arr);
}
private:
@ -234,6 +334,8 @@ private:
bool should_stop;
uint64_t prev_ticks;
uint64_t prev_resized_ticks;
bool resized;
struct
{
@ -248,6 +350,8 @@ private:
unsigned int tile_count;
unsigned int color_buffer;
sprstk_palette* color_info_map;
unsigned int a_buffer;
unsigned int z_buffer;
} gl;
void init_sdl()
@ -262,7 +366,7 @@ private:
SDL_GL_SetAttribute(SDL_GL_CONTEXT_PROFILE_MASK, SDL_GL_CONTEXT_PROFILE_CORE);
SDL_GL_SetAttribute(SDL_GL_DOUBLEBUFFER, 1);
SDL_GL_SetAttribute(SDL_GL_DEPTH_SIZE, 24);
SDL_GL_SetAttribute(SDL_GL_CONTEXT_FLAGS, SDL_GL_CONTEXT_DEBUG_FLAG);
//SDL_GL_SetAttribute(SDL_GL_CONTEXT_FLAGS, SDL_GL_CONTEXT_DEBUG_FLAG);
sdl.window = SDL_CreateWindow("sprstk", 640, 480, SDL_WINDOW_OPENGL | SDL_WINDOW_RESIZABLE);
if (!sdl.window)
@ -294,9 +398,6 @@ private:
throw application_error("Mesh shaders not supported");
}
glEnable(GL_BLEND);
glBlendFuncSeparate(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA, GL_ONE, GL_ZERO);
glDebugMessageCallback([](GLenum source, GLenum type, GLuint id, GLenum severity, GLsizei length, const GLchar* message, const void* userdata)
{
SDL_LogWarn(SDL_LOG_CATEGORY_APPLICATION, "%s", message);
@ -365,15 +466,49 @@ private:
gl.color_info_map = (sprstk_palette*)glMapNamedBufferRange(gl.color_buffer, 0, sizeof(sprstk_palette) * (1 << 5), GL_MAP_WRITE_BIT | GL_MAP_COHERENT_BIT);
const float arr[4] = {1, 0, 0, 1};
glProgramUniformMatrix2fv(gl.program, 2, 1, false, arr);
glProgramUniformMatrix2fv(gl.program, 3, 1, false, arr);
glProgramUniform1f(gl.program, 2, 1);
create_buffers();
}
void destroy_gl()
{
glDeleteTextures(1, &gl.a_buffer);
glDeleteTextures(1, &gl.z_buffer);
glDeleteProgram(gl.program);
glDeleteBuffers(1, &gl.tile_buffer);
SDL_GL_DestroyContext(sdl.context);
}
void create_buffers()
{
if (gl.a_buffer)
{
glDeleteTextures(1, &gl.a_buffer);
glDeleteTextures(1, &gl.z_buffer);
}
int width, height;
SDL_GetWindowSizeInPixels(sdl.window, &width, &height);
glGenTextures(1, &gl.a_buffer);
glBindTexture(GL_TEXTURE_3D, gl.a_buffer);
glTexStorage3D(GL_TEXTURE_3D, 1, GL_RGBA8, width, height, OIT_LAYERS);
glGenTextures(1, &gl.z_buffer);
glBindTexture(GL_TEXTURE_3D, gl.z_buffer);
glTexStorage3D(GL_TEXTURE_3D, 1, GL_R8UI, width, height, OIT_LAYERS);
constexpr uint32_t color = 0;
glClearTexImage(gl.a_buffer, 0, GL_RGBA, GL_UNSIGNED_INT, &color);
glBindImageTexture(0, gl.a_buffer, 0, true, 0, GL_READ_WRITE, GL_RGBA8);
constexpr uint8_t z = 0xFF;
glClearTexImage(gl.z_buffer, 0, GL_RED_INTEGER, GL_UNSIGNED_BYTE, &z);
glBindImageTexture(1, gl.z_buffer, 0, true, 0, GL_READ_WRITE, GL_R8UI);
glBindTexture(GL_TEXTURE_3D, gl.a_buffer);
}
};
extern "C"
@ -420,6 +555,11 @@ void sprstk_stop(sprstk* instance)
instance->stop();
}
void sprstk_clear(sprstk* instance)
{
instance->clear();
}
void sprstk_put(sprstk* instance, int x, int y, unsigned int layers, unsigned int palette_lookup)
{
instance->put(x, y, layers, palette_lookup);
@ -435,6 +575,11 @@ void sprstk_set_palette(sprstk* instance, unsigned int index, const sprstk_palet
instance->set_palette(index, palette);
}
void sprstk_set_scale(sprstk* instance, float scale)
{
instance->set_scale(scale);
}
void sprstk_set_angle(sprstk* instance, float angle)
{
instance->set_angle(angle);