commit f4605dbbd165348362ea38b6313b0818196cc675 Author: Jeff Carr Date: Mon Feb 19 07:16:10 2024 -0600 pulled out from my fork of upstream repo diff --git a/.gitignore b/.gitignore new file mode 100644 index 0000000..a630ed4 --- /dev/null +++ b/.gitignore @@ -0,0 +1,3 @@ +*.swp +go.mod +go.sum diff --git a/Makefile b/Makefile new file mode 100644 index 0000000..e9f03b9 --- /dev/null +++ b/Makefile @@ -0,0 +1,18 @@ +# go get -u github.com/faiface/pixel-examples +# cd ~/go/src/github.com/faiface/pixel-examples/community/seascape-shader + +all: + GO111MODULE=off go build + ./seascape-shader + +push: + git pull + git add --all + -git commit -a -s + git push + +update: + git pull + +diff: + git diff diff --git a/README.md b/README.md new file mode 100644 index 0000000..7d1dea7 --- /dev/null +++ b/README.md @@ -0,0 +1,133 @@ +# Shadertoy to Pixel shader conversion + +This will show you an example how you can take an example from [shadertoy.com](shadertoy.com) and use it with the Pixel Shader support. + +["Seascape" by Alexander Alekseev aka TDM - 2014](https://www.shadertoy.com/view/Ms2SD1) is a nice one. It's very impressive and doesn't use textures so that simplifies things for us. Let's try that one. + +Looking at the seascape.glsl example you can see **iResolution**, **iTime** and **iMouse** in there. + +These are commonly needed to be exposed because these things are coming from outside and needs to be updated. Any other variable you need to have changed/updated from code can be exposed like those. + +## Command line arguments + +``` +./seascape-shader -h # will show you the command line options + +./seascape-shader -filename ./shaders/seascape.glsl # Seascape +./seascape-shader -filename ./shaders/planetfall.glsl # Planet Fall demo +``` + +## Exposing variables + +How to expose variables like this? + +Well, first we need to figure out what type of variables they are. Looking at the shader, you can see **iResolution.x** in there. This tells you that it's not a simple type. In this case it's a **vec2***, a **Vector containing 2 values, x and y**. This makes sense since resolution is described by x and y. That is, width and height. + +And thus, we create our variable in Go with like so: +``` +uResolution := mgl32.Vec2{float32(win.Bounds().W()), float32(win.Bounds().H())} +``` +That is, to be of the type **mgl32.Vec2**. Here we create it by taking the window's width and height. + +**iTime** is just a float, and thus that is just created like so: +``` +var uTime float32 +``` + +For the **iMouse**, it's a **mgl32.Vec4**, a **Vector containing 4 variables**. We only use x and y for the mouse position here though. +``` +var uMouse mgl32.Vec4 +``` + +And finally, to make our variables available in the shader itself we use: +``` +canvas.SetUniform(name string, value interface{}) +``` + +We create a handy function to do this: + +``` go +func EasyBindUniforms(c *pixelgl.Canvas, unifs ...interface{}) { + if len(unifs)%2 != 0 { + panic("needs to be divisable by 2") + } + for i := 0; i < len(unifs); i += 2 { + + c.SetUniform(unifs[i+0].(string), unifs[i+1]) + } +} +``` +and we call that function like so: + +``` go + EasyBindUniforms(canvas, + "uResolution", &uResolution, + "uTime", &uTime, + "uMouse", &uMouse, + ) +``` + +## Updating shader source file + +We also need to do some updates to the shader file itself to match these variables. First thing would be to add the variables we exposed in Go. + +``` +uniform vec2 uResolution; +uniform float uTime; +uniform vec4 uMouse; +``` +Then we just rename the variables to match. + +We also need to rename the main function itself, as the one used here is specific for use with shadertoy. For our shader, the entrypoint is main(). So we rename: +``` +void mainImage( out vec4 fragColor, in vec2 fragCoord ) +``` +to +``` +void main() { +``` + + +Also, rename: +``` +fragCoord +``` +to +``` +gl_FragCoord +``` +because this is available globaly in the OpenGL space for the shader. + +We also need to add: +``` +out vec4 fragColor; +``` + +to expose that. + +Lastly, we need to add: +``` +#version 330 core +``` +at the top to tell what version we require. + + +## Using shader +To use the shader in our canvas we do: +``` +canvas.SetFragmentShader(fragSource string) +``` +where fragSource is the fragment shader, not a path fo a file. + +# + +## Result converting shadertoy shader to use with Pixel + +Here is a diff of the changes: + +![code changes](shader_diffs.png "Code changes") + + +And that is it. Running the program we should see this: + +![seascape animation](seascape.gif "Seascape animation") diff --git a/config.go b/config.go new file mode 100644 index 0000000..da8313a --- /dev/null +++ b/config.go @@ -0,0 +1,79 @@ +package main + +/* + This simply parses the command line arguments using the default golang + package called 'flag'. This can be used as a simple template to parse + command line arguments in other programs. + + It puts everything in the 'config' package which I think is a good + wrapper around the 'flags' package and doesn't need a whole mess of + global variables +*/ + +import "log" +import "os" +import "flag" +import "fmt" +import "github.com/gookit/config" + +var customUsage = func() { + fmt.Fprintf(flag.CommandLine.Output(), "Usage of %s:\n", os.Args[0]) + flag.PrintDefaults() + + fmt.Println("") + fmt.Println("EXAMPLES:") + fmt.Println("") + fmt.Println(os.Args[0] + " --width 1024 --height 768 --drift .1 --filename shaders/seascape.glsl") + fmt.Println(os.Args[0] + " --width 640 --height 480 --filename shaders/planetfall.glsl") + fmt.Println("") +} + +func parseFlags() { + var version string + var race bool + var filename string + var width int + var height int + var glDrift float64 + + flag.StringVar (&version, "version", "v0.1", "Set compiled in version string") + + flag.StringVar (&filename, "filename", "shaders/seascape.glsl", "path to GLSL file") + flag.IntVar (&width, "width", 1024, "Width of the OpenGL Window") + flag.IntVar (&height, "height", 768, "Height of the OpenGL Window") + + flag.Float64Var (&glDrift, "drift", 0.01, "Speed of the gradual camera drift") + flag.BoolVar (&race, "race", race, "Use race detector") + + // Set the output if something fails to stdout rather than stderr + flag.CommandLine.SetOutput(os.Stdout) + + flag.Usage = customUsage + flag.Parse() + + if flag.Parsed() { + log.Println("flag.Parse() worked") + } else { + log.Println("flag.Parse() failed") + } + + // keys := []string{"filename", "width", "height", "drift"} + // keys := []string{"width", "height", "drift"} + +// keys := []string{"height"} +// config.LoadFlags(keys) + + config.Set("width", width) + config.Set("height", height) + config.Set("glDrift", glDrift) + config.Set("filename", filename) +} + +func parseConfig() { + config.WithOptions(config.ParseEnv) + parseFlags() + + // config.LoadOSEnv([]string{"MAIL"}) + // config.LoadOSEnv([]string{"USER"}) + // config.LoadOSEnv([]string{"BUILDDEBUG"}) +} diff --git a/planetfall.glsl b/planetfall.glsl new file mode 100644 index 0000000..d1a74e6 --- /dev/null +++ b/planetfall.glsl @@ -0,0 +1,333 @@ +// Created by inigo quilez - iq/2018 +// License Creative Commons Attribution-NonCommercial-ShareAlike 3.0 Unported License. + +// Pretty much a modification to Klems' shader (https://www.shadertoy.com/view/XlcfRs) +// Youtube version: https://www.youtube.com/watch?v=q1OBrqtl7Yo + +#version 330 core + +// Change AA to 1 if it renders too slow for you +#define AA 1 + +uniform vec2 uResolution; +uniform float uTime; // shader playback time (in seconds) +uniform vec4 uMouse; + +// there is tearing on my box. is this because this isn't working? -- jcarr +uniform int iFrame; // shader playback frame + +out vec4 fragColor; +// in vec2 fragCoord; + +mat3 makeBase( in vec3 w ) +{ + float k = inversesqrt(1.0-w.y*w.y); + return mat3( vec3(-w.z,0.0,w.x)*k, + vec3(-w.x*w.y,1.0-w.y*w.y,-w.y*w.z)*k, + w); +} + +#define ZERO (min(iFrame,0)) + +// http://iquilezles.org/www/articles/intersectors/intersectors.htm +vec2 sphIntersect( in vec3 ro, in vec3 rd, in float rad ) +{ + float b = dot( ro, rd ); + float c = dot( ro, ro ) - rad*rad; + float h = b*b - c; + if( h<0.0 ) return vec2(-1.0); + h = sqrt(h); + return vec2(-b-h,-b+h); +} + +// http://iquilezles.org/www/articles/distfunctions/distfunctions.htm +float sdCapsule( in vec3 p, in float b, in float r ) +{ + float h = clamp( p.z/b, 0.0, 1.0 ); + return length( p - vec3(0.0,0.0,b)*h ) - r;//*(0.2+1.6*h); +} + +// modified Keinert et al's inverse Spherical Fibonacci Mapping +vec4 inverseSF( in vec3 p, const in float n ) +{ + const float PI = 3.14159265359; + const float PHI = 1.61803398875; + + float phi = min(atan(p.y,p.x),PI); + float k = max(floor(log(n*PI*sqrt(5.0)*(1.-p.z*p.z))/log(PHI+1.)),2.0); + float Fk = pow(PHI,k)/sqrt(5.0); + vec2 F = vec2(round(Fk),round(Fk*PHI)); + vec2 G = PI*(fract((F+1.0)*PHI)-(PHI-1.0)); + + mat2 iB = mat2(F.y,-F.x,G.y,-G.x)/(F.y*G.x-F.x*G.y); + vec2 c = floor(iB*0.5*vec2(phi,n*p.z-n+1.0)); + + float ma = 0.0; + vec4 res = vec4(0); + for( int s=0; s<4; s++ ) + { + vec2 uv = vec2(s&1,s>>1); + float i = dot(F,uv+c); + float phi = 2.0*PI*fract(i*PHI); + float cT = 1.0 - (2.0*i+1.0)/n; + float sT = sqrt(1.0-cT*cT); + vec3 q = vec3(cos(phi)*sT, sin(phi)*sT,cT); + float a = dot(p,q); + if (a > ma) + { + ma = a; + res.xyz = q; + res.w = i; + } + } + return res; +} + +float map( in vec3 p, out vec4 color, const in bool doColor ) +{ + float lp = length(p); + float dmin = lp-1.0; + { + vec3 w = p/lp; + vec4 fibo = inverseSF(w, 700.0); + float hh = 1.0 - smoothstep(0.05,0.1,length(fibo.xyz-w)); + dmin -= 0.07*hh; + color = vec4(0.05,0.1,0.1,1.0)*hh * (1.0+0.5*sin(fibo.w*111.1)); + } + + + float s = 1.0; + + for( int i=0; i<3; i++ ) + { + float h = float(i)/float(3-1); + + vec4 f = inverseSF(normalize(p), 65.0 + h*75.0); + + // snap + p -= f.xyz; + + // orient to surface + p = p*makeBase(f.xyz); + + // scale + float scale = 6.6 + 2.0*sin(111.0*f.w); + p *= scale; + p.xy *= 1.2; + + //translate + p.z -= 3.0 - length(p.xy)*0.6*sin(f.w*212.1); + + // measure distance + s *= scale; + float d = sdCapsule( p, -6.0, 0.42 ); + d /= s; + + if( d>1)&1),((i>>1)&1),(i&1))-1.0); + n += e*map(pos+e*ep, kk, false); + } + return normalize(n); +#endif + +} + +// http://iquilezles.org/www/articles/rmshadows/rmshadows.htm +float calcSoftshadow( in vec3 ro, in vec3 rd, float tmin, float tmax, const float k ) +{ + vec2 bound = sphIntersect( ro, rd, 2.1 ); + tmin = max(tmin,bound.x); + tmax = min(tmax,bound.y); + + float res = 1.0; + float t = tmin; + for( int i=0; i<50; i++ ) + { + vec4 kk; + float h = map( ro + rd*t, kk, false ); + res = min( res, k*h/t ); + t += clamp( h, 0.02, 0.20 ); + if( res<0.005 || t>tmax ) break; + } + return clamp( res, 0.0, 1.0 ); +} + +float raycast(in vec3 ro, in vec3 rd, in float tmin, in float tmax ) +{ + vec4 kk; + float t = tmin; + for( int i=0; i<512; i++ ) + { + vec3 p = ro + t*rd; + float h = map(p,kk,false); + if( abs(h)<(0.15*t/uResolution.x) ) break; + t += h*0.5; + if( t>tmax ) return -1.0;; + } + //if( t>tmax ) t=-1.0; + + return t; +} + +// void mainImage( out vec4 fragColor, in vec2 fragCoord ) +// gl_FragCoord.xy +void main() +{ + float an = (uTime-10.0)*0.05; + + // camera + vec3 ro = vec3( 4.5*sin(an), 0.0, 4.5*cos(an) ); + vec3 ta = vec3( 0.0, 0.0, 0.0 ); + // camera-to-world rotation + mat3 ca = makeBase( normalize(ta-ro) ); + + // render + vec3 tot = vec3(0.0); + + #if AA>1 + for( int m=ZERO; m0.0 ) + { + // raycast + float t = raycast(ro, rd, bound.x, bound.y ); + if( t>0.0 ) + { + // local geometry + vec3 pos = ro + t*rd; + vec3 nor = calcNormal(pos, 0.01); + vec3 upp = normalize(pos); + + // color and occlusion + vec4 mate; map(pos, mate, true); + + // lighting + col = vec3(0.0); + + // key ligh + { + // dif + vec3 lig = normalize(vec3(1.0,0.0,0.7)); + float dif = clamp(0.5+0.5*dot(nor,lig),0.0,1.0); + float sha = calcSoftshadow( pos+0.0001*nor, lig, 0.0001, 2.0, 6.0 ); + col += mate.xyz*dif*vec3(1.8,0.6,0.5)*1.1*vec3(sha,sha*0.3+0.7*sha*sha,sha*sha); + // spec + vec3 hal = normalize(lig-rd); + float spe = clamp( dot(nor,hal), 0.0, 1.0 ); + float fre = clamp( dot(-rd,lig), 0.0, 1.0 ); + fre = 0.2 + 0.8*pow(fre,5.0); + spe *= spe; + spe *= spe; + spe *= spe; + col += 1.0*(0.25+0.75*mate.x)*spe*dif*sha*fre; + } + + // back light + { + vec3 lig = normalize(vec3(-1.0,0.0,0.0)); + float dif = clamp(0.5+0.5*dot(nor,lig),0.0,1.0); + col += mate.rgb*dif*vec3(1.2,0.9,0.6)*0.2*mate.w; + } + + // dome light + { + float dif = clamp(0.3+0.7*dot(nor,upp),0.0,1.0); + #if 0 + dif *= 0.05 + 0.95*calcSoftshadow( pos+0.0001*nor, upp, 0.0001, 1.0, 1.0 ); + col += mate.xyz*dif*5.0*vec3(0.1,0.1,0.3)*mate.w; + #else + col += mate.xyz*dif*3.0*vec3(0.1,0.1,0.3)*mate.w*(0.2+0.8*mate.w); + #endif + } + + // fake sss + { + float fre = clamp(1.0+dot(rd,nor),0.0,1.0); + col += 0.3*vec3(1.0,0.3,0.2)*mate.xyz*mate.xyz*fre*fre*mate.w; + } + + // grade/sss + { + col = 2.0*pow( col, vec3(0.7,0.85,1.0) ); + } + + // exposure control + col *= 0.7 + 0.3*smoothstep(0.0,25.0,abs(uTime-31.0)); + + // display fake occlusion + //col = mate.www; + } + } + + + // gamma + col = pow( col, vec3(0.4545) ); + + tot += col; + #if AA>1 + } + tot /= float(AA*AA); + #endif + + // vignetting + vec2 q = gl_FragCoord.xy/uResolution.xy; + tot *= pow( 16.0*q.x*q.y*(1.0-q.x)*(1.0-q.y), 0.2 ); + + fragColor = vec4( tot, 1.0 ); +} diff --git a/psutil.go b/psutil.go new file mode 100644 index 0000000..2fb370e --- /dev/null +++ b/psutil.go @@ -0,0 +1,54 @@ +package main + +import ( + "io/ioutil" + + "github.com/faiface/pixel" + "github.com/faiface/pixel/pixelgl" +) + +// Pixel Shader utility functions + +// EasyBindUniforms does all the work for you, just pass in a +// valid array adhering to format: String, Variable, ... +// +// example: +// +// var uTimeVar float32 +// var uMouseVar mgl32.Vec4 +// +// EasyBindUniforms(win.GetCanvas(), +// "u_time", &uTimeVar, +// "u_mouse", &uMouseVar, +// ) +// +func EasyBindUniforms(c *pixelgl.Canvas, unifs ...interface{}) { + if len(unifs)%2 != 0 { + panic("needs to be divisable by 2") + } + for i := 0; i < len(unifs); i += 2 { + + c.SetUniform(unifs[i+0].(string), unifs[i+1]) + } +} + +// CenterWindow will... center the window +func CenterWindow(win *pixelgl.Window) { + x, y := pixelgl.PrimaryMonitor().Size() + width, height := win.Bounds().Size().XY() + win.SetPos( + pixel.V( + x/2-width/2, + y/2-height/2, + ), + ) +} + +// LoadFileToString loads the contents of a file into a string +func LoadFileToString(filename string) (string, error) { + b, err := ioutil.ReadFile(filename) + if err != nil { + return "", err + } + return string(b), nil +} diff --git a/seascape.glsl b/seascape.glsl new file mode 100644 index 0000000..7a69f40 --- /dev/null +++ b/seascape.glsl @@ -0,0 +1,196 @@ +/* + * "Seascape" by Alexander Alekseev aka TDM - 2014 + * License Creative Commons Attribution-NonCommercial-ShareAlike 3.0 Unported License. + * Contact: tdmaav@gmail.com + */ + +#version 330 core + +uniform vec2 uResolution; +uniform float uTime; +uniform vec4 uMouse; + +// This is how much you are drifting around. Zero means it only moves when the mouse moves +uniform float uDrift; + +out vec4 fragColor; + +const int NUM_STEPS = 8; +const float PI = 3.141592; +const float EPSILON = 1e-3; +#define EPSILON_NRM (0.1 / uResolution.x) + +// sea +const int ITER_GEOMETRY = 3; +const int ITER_FRAGMENT = 5; +const float SEA_HEIGHT = 0.6; +const float SEA_CHOPPY = 4.0; +const float SEA_SPEED = 0.8; +const float SEA_FREQ = 0.16; +const vec3 SEA_BASE = vec3(0.1,0.19,0.22); +const vec3 SEA_WATER_COLOR = vec3(0.8,0.9,0.6); +#define SEA_TIME (1.0 + uTime * SEA_SPEED) +const mat2 octave_m = mat2(1.6,1.2,-1.2,1.6); + +// math +mat3 fromEuler(vec3 ang) { + vec2 a1 = vec2(sin(ang.x),cos(ang.x)); + vec2 a2 = vec2(sin(ang.y),cos(ang.y)); + vec2 a3 = vec2(sin(ang.z),cos(ang.z)); + mat3 m; + m[0] = vec3(a1.y*a3.y+a1.x*a2.x*a3.x,a1.y*a2.x*a3.x+a3.y*a1.x,-a2.y*a3.x); + m[1] = vec3(-a2.y*a1.x,a1.y*a2.y,a2.x); + m[2] = vec3(a3.y*a1.x*a2.x+a1.y*a3.x,a1.x*a3.x-a1.y*a3.y*a2.x,a2.y*a3.y); + return m; +} +float hash( vec2 p ) { + float h = dot(p,vec2(127.1,311.7)); + return fract(sin(h)*43758.5453123); +} +float noise( in vec2 p ) { + vec2 i = floor( p ); + vec2 f = fract( p ); + vec2 u = f*f*(3.0-2.0*f); + return -1.0+2.0*mix( mix( hash( i + vec2(0.0,0.0) ), + hash( i + vec2(1.0,0.0) ), u.x), + mix( hash( i + vec2(0.0,1.0) ), + hash( i + vec2(1.0,1.0) ), u.x), u.y); +} + +// lighting +float diffuse(vec3 n,vec3 l,float p) { + return pow(dot(n,l) * 0.4 + 0.6,p); +} +float specular(vec3 n,vec3 l,vec3 e,float s) { + float nrm = (s + 8.0) / (PI * 8.0); + return pow(max(dot(reflect(e,n),l),0.0),s) * nrm; +} + +// sky +vec3 getSkyColor(vec3 e) { + e.y = max(e.y,0.0); + return vec3(pow(1.0-e.y,2.0), 1.0-e.y, 0.6+(1.0-e.y)*0.4); +} + +// sea +float sea_octave(vec2 uv, float choppy) { + uv += noise(uv); + vec2 wv = 1.0-abs(sin(uv)); + vec2 swv = abs(cos(uv)); + wv = mix(wv,swv,wv); + return pow(1.0-pow(wv.x * wv.y,0.65),choppy); +} + +float map(vec3 p) { + float freq = SEA_FREQ; + float amp = SEA_HEIGHT; + float choppy = SEA_CHOPPY; + vec2 uv = p.xz; uv.x *= 0.75; + + float d, h = 0.0; + for(int i = 0; i < ITER_GEOMETRY; i++) { + d = sea_octave((uv+SEA_TIME)*freq,choppy); + d += sea_octave((uv-SEA_TIME)*freq,choppy); + h += d * amp; + uv *= octave_m; freq *= 1.9; amp *= 0.22; + choppy = mix(choppy,1.0,0.2); + } + return p.y - h; +} + +float map_detailed(vec3 p) { + float freq = SEA_FREQ; + float amp = SEA_HEIGHT; + float choppy = SEA_CHOPPY; + vec2 uv = p.xz; uv.x *= 0.75; + + float d, h = 0.0; + for(int i = 0; i < ITER_FRAGMENT; i++) { + d = sea_octave((uv+SEA_TIME)*freq,choppy); + d += sea_octave((uv-SEA_TIME)*freq,choppy); + h += d * amp; + uv *= octave_m; freq *= 1.9; amp *= 0.22; + choppy = mix(choppy,1.0,0.2); + } + return p.y - h; +} + +vec3 getSeaColor(vec3 p, vec3 n, vec3 l, vec3 eye, vec3 dist) { + float fresnel = clamp(1.0 - dot(n,-eye), 0.0, 1.0); + fresnel = pow(fresnel,3.0) * 0.65; + + vec3 reflected = getSkyColor(reflect(eye,n)); + vec3 refracted = SEA_BASE + diffuse(n,l,80.0) * SEA_WATER_COLOR * 0.12; + + vec3 color = mix(refracted,reflected,fresnel); + + float atten = max(1.0 - dot(dist,dist) * 0.001, 0.0); + color += SEA_WATER_COLOR * (p.y - SEA_HEIGHT) * 0.18 * atten; + + color += vec3(specular(n,l,eye,60.0)); + + return color; +} + +// tracing +vec3 getNormal(vec3 p, float eps) { + vec3 n; + n.y = map_detailed(p); + n.x = map_detailed(vec3(p.x+eps,p.y,p.z)) - n.y; + n.z = map_detailed(vec3(p.x,p.y,p.z+eps)) - n.y; + n.y = eps; + return normalize(n); +} + +float heightMapTracing(vec3 ori, vec3 dir, out vec3 p) { + float tm = 0.0; + float tx = 1000.0; + float hx = map(ori + dir * tx); + if(hx > 0.0) return tx; + float hm = map(ori + dir * tm); + float tmid = 0.0; + for(int i = 0; i < NUM_STEPS; i++) { + tmid = mix(tm,tx, hm/(hm-hx)); + p = ori + dir * tmid; + float hmid = map(p); + if(hmid < 0.0) { + tx = tmid; + hx = hmid; + } else { + tm = tmid; + hm = hmid; + } + } + return tmid; +} + +// main +void main() +{ + vec2 uv = gl_FragCoord.xy / uResolution.xy; + uv = uv * 2.0 - 1.0; + uv.x *= uResolution.x / uResolution.y; + float time = uTime * uDrift * 5 + uMouse.x*0.01; + + // ray + vec3 ang = vec3(sin(time*3.0)*0.1,sin(time)*0.2+0.3,time); + vec3 ori = vec3(0.0,3.5,time*5.0); + vec3 dir = normalize(vec3(uv.xy,-2.0)); dir.z += length(uv) * 0.15; + dir = normalize(dir) * fromEuler(ang); + + // tracing + vec3 p; + heightMapTracing(ori,dir,p); + vec3 dist = p - ori; + vec3 n = getNormal(p, dot(dist,dist) * EPSILON_NRM); + vec3 light = normalize(vec3(0.0,1.0,0.8)); + + // color + vec3 color = mix( + getSkyColor(dir), + getSeaColor(p,n,light,dir,dist), + pow(smoothstep(0.0,-0.05,dir.y),0.3)); + + // post + fragColor = vec4(pow(color,vec3(0.75)), 1.0); +} diff --git a/seascape.go b/seascape.go new file mode 100644 index 0000000..abfee6e --- /dev/null +++ b/seascape.go @@ -0,0 +1,86 @@ +package main + +import ( + "time" + + "github.com/go-gl/mathgl/mgl32" + + "github.com/faiface/pixel" + "github.com/faiface/pixel/pixelgl" + "golang.org/x/image/colornames" +) + +import "log" +import "github.com/gookit/config" + +func run() { + // Set up window configs + log.Println("width = ", config.Int("width"), "height = ", config.String("height")) + cfg := pixelgl.WindowConfig{ // Default: 1024 x 768 + Title: "Golang GLSL", + Bounds: pixel.R(0, 0, config.Float("width"), config.Float("height")), + VSync: true, + } + + win, err := pixelgl.NewWindow(cfg) + if err != nil { + panic(err) + } + + camVector := win.Bounds().Center() + + bounds := win.Bounds() + bounds.Max = bounds.Max.ScaledXY(pixel.V(1.0, 1.0)) + + // I am putting all shader example initializing stuff here for + // easier reference to those learning to use this functionality + + log.Println("Load GSGL file = ", config.String("filename")) + fragSource, err := LoadFileToString(config.String("filename")) + + if err != nil { + panic(err) + } + + var uMouse mgl32.Vec4 + var uTime float32 + log.Println("glDrift = ", config.String("glDrift")) + var glDrift float32 = float32(config.Float("glDrift")) + + canvas := win.Canvas() + uResolution := mgl32.Vec2{float32(win.Bounds().W()), float32(win.Bounds().H())} + + EasyBindUniforms(canvas, + "uResolution", &uResolution, + "uTime", &uTime, + "uMouse", &uMouse, + "uDrift", &glDrift, + ) + + canvas.SetFragmentShader(fragSource) + + start := time.Now() + + // Game Loop + for !win.Closed() { + uTime = float32(time.Since(start).Seconds()) + mpos := win.MousePosition() + uMouse[0] = float32(mpos.X) + uMouse[1] = float32(mpos.Y) + + win.Clear(colornames.Black) + + // Drawing to the screen + canvas.Draw(win, pixel.IM.Moved(camVector)) + + win.Update() + } + +} + +func main() { + // This parses the command line arguments + parseConfig() + + pixelgl.Run(run) +} diff --git a/seascape_original.glsl b/seascape_original.glsl new file mode 100644 index 0000000..b70f887 --- /dev/null +++ b/seascape_original.glsl @@ -0,0 +1,184 @@ +/* + * "Seascape" by Alexander Alekseev aka TDM - 2014 + * License Creative Commons Attribution-NonCommercial-ShareAlike 3.0 Unported License. + * Contact: tdmaav@gmail.com + */ + +const int NUM_STEPS = 8; +const float PI = 3.141592; +const float EPSILON = 1e-3; +#define EPSILON_NRM (0.1 / iResolution.x) + +// sea +const int ITER_GEOMETRY = 3; +const int ITER_FRAGMENT = 5; +const float SEA_HEIGHT = 0.6; +const float SEA_CHOPPY = 4.0; +const float SEA_SPEED = 0.8; +const float SEA_FREQ = 0.16; +const vec3 SEA_BASE = vec3(0.1,0.19,0.22); +const vec3 SEA_WATER_COLOR = vec3(0.8,0.9,0.6); +#define SEA_TIME (1.0 + iTime * SEA_SPEED) +const mat2 octave_m = mat2(1.6,1.2,-1.2,1.6); + +// math +mat3 fromEuler(vec3 ang) { + vec2 a1 = vec2(sin(ang.x),cos(ang.x)); + vec2 a2 = vec2(sin(ang.y),cos(ang.y)); + vec2 a3 = vec2(sin(ang.z),cos(ang.z)); + mat3 m; + m[0] = vec3(a1.y*a3.y+a1.x*a2.x*a3.x,a1.y*a2.x*a3.x+a3.y*a1.x,-a2.y*a3.x); + m[1] = vec3(-a2.y*a1.x,a1.y*a2.y,a2.x); + m[2] = vec3(a3.y*a1.x*a2.x+a1.y*a3.x,a1.x*a3.x-a1.y*a3.y*a2.x,a2.y*a3.y); + return m; +} +float hash( vec2 p ) { + float h = dot(p,vec2(127.1,311.7)); + return fract(sin(h)*43758.5453123); +} +float noise( in vec2 p ) { + vec2 i = floor( p ); + vec2 f = fract( p ); + vec2 u = f*f*(3.0-2.0*f); + return -1.0+2.0*mix( mix( hash( i + vec2(0.0,0.0) ), + hash( i + vec2(1.0,0.0) ), u.x), + mix( hash( i + vec2(0.0,1.0) ), + hash( i + vec2(1.0,1.0) ), u.x), u.y); +} + +// lighting +float diffuse(vec3 n,vec3 l,float p) { + return pow(dot(n,l) * 0.4 + 0.6,p); +} +float specular(vec3 n,vec3 l,vec3 e,float s) { + float nrm = (s + 8.0) / (PI * 8.0); + return pow(max(dot(reflect(e,n),l),0.0),s) * nrm; +} + +// sky +vec3 getSkyColor(vec3 e) { + e.y = max(e.y,0.0); + return vec3(pow(1.0-e.y,2.0), 1.0-e.y, 0.6+(1.0-e.y)*0.4); +} + +// sea +float sea_octave(vec2 uv, float choppy) { + uv += noise(uv); + vec2 wv = 1.0-abs(sin(uv)); + vec2 swv = abs(cos(uv)); + wv = mix(wv,swv,wv); + return pow(1.0-pow(wv.x * wv.y,0.65),choppy); +} + +float map(vec3 p) { + float freq = SEA_FREQ; + float amp = SEA_HEIGHT; + float choppy = SEA_CHOPPY; + vec2 uv = p.xz; uv.x *= 0.75; + + float d, h = 0.0; + for(int i = 0; i < ITER_GEOMETRY; i++) { + d = sea_octave((uv+SEA_TIME)*freq,choppy); + d += sea_octave((uv-SEA_TIME)*freq,choppy); + h += d * amp; + uv *= octave_m; freq *= 1.9; amp *= 0.22; + choppy = mix(choppy,1.0,0.2); + } + return p.y - h; +} + +float map_detailed(vec3 p) { + float freq = SEA_FREQ; + float amp = SEA_HEIGHT; + float choppy = SEA_CHOPPY; + vec2 uv = p.xz; uv.x *= 0.75; + + float d, h = 0.0; + for(int i = 0; i < ITER_FRAGMENT; i++) { + d = sea_octave((uv+SEA_TIME)*freq,choppy); + d += sea_octave((uv-SEA_TIME)*freq,choppy); + h += d * amp; + uv *= octave_m; freq *= 1.9; amp *= 0.22; + choppy = mix(choppy,1.0,0.2); + } + return p.y - h; +} + +vec3 getSeaColor(vec3 p, vec3 n, vec3 l, vec3 eye, vec3 dist) { + float fresnel = clamp(1.0 - dot(n,-eye), 0.0, 1.0); + fresnel = pow(fresnel,3.0) * 0.65; + + vec3 reflected = getSkyColor(reflect(eye,n)); + vec3 refracted = SEA_BASE + diffuse(n,l,80.0) * SEA_WATER_COLOR * 0.12; + + vec3 color = mix(refracted,reflected,fresnel); + + float atten = max(1.0 - dot(dist,dist) * 0.001, 0.0); + color += SEA_WATER_COLOR * (p.y - SEA_HEIGHT) * 0.18 * atten; + + color += vec3(specular(n,l,eye,60.0)); + + return color; +} + +// tracing +vec3 getNormal(vec3 p, float eps) { + vec3 n; + n.y = map_detailed(p); + n.x = map_detailed(vec3(p.x+eps,p.y,p.z)) - n.y; + n.z = map_detailed(vec3(p.x,p.y,p.z+eps)) - n.y; + n.y = eps; + return normalize(n); +} + +float heightMapTracing(vec3 ori, vec3 dir, out vec3 p) { + float tm = 0.0; + float tx = 1000.0; + float hx = map(ori + dir * tx); + if(hx > 0.0) return tx; + float hm = map(ori + dir * tm); + float tmid = 0.0; + for(int i = 0; i < NUM_STEPS; i++) { + tmid = mix(tm,tx, hm/(hm-hx)); + p = ori + dir * tmid; + float hmid = map(p); + if(hmid < 0.0) { + tx = tmid; + hx = hmid; + } else { + tm = tmid; + hm = hmid; + } + } + return tmid; +} + +// main +void mainImage( out vec4 fragColor, in vec2 fragCoord ) { + vec2 uv = fragCoord.xy / iResolution.xy; + uv = uv * 2.0 - 1.0; + uv.x *= iResolution.x / iResolution.y; + float time = iTime * 0.3 + iMouse.x*0.01; + + // ray + vec3 ang = vec3(sin(time*3.0)*0.1,sin(time)*0.2+0.3,time); + vec3 ori = vec3(0.0,3.5,time*5.0); + vec3 dir = normalize(vec3(uv.xy,-2.0)); dir.z += length(uv) * 0.15; + dir = normalize(dir) * fromEuler(ang); + + // tracing + vec3 p; + heightMapTracing(ori,dir,p); + vec3 dist = p - ori; + vec3 n = getNormal(p, dot(dist,dist) * EPSILON_NRM); + vec3 light = normalize(vec3(0.0,1.0,0.8)); + + // color + vec3 color = mix( + getSkyColor(dir), + getSeaColor(p,n,light,dir,dist), + pow(smoothstep(0.0,-0.05,dir.y),0.3)); + + // post + fragColor = vec4(pow(color,vec3(0.75)), 1.0); +} \ No newline at end of file