Add more image generation functions: radial gradient and perlin noise

examples/textures/textures_image_generation.c

@@ -11,7 +11,7 @@
 
 #include "raylib.h"
 
-#define TEXTURES_NUM 5 // for now we have 5 generation algorithms
+#define TEXTURES_NUM 7 // for now we have 7 generation algorithms
 
 int main()
 {
@@ -22,16 +22,20 @@ int main()
 
     Image verticalGradient = GenImageGradientV(screenWidth, screenHeight, RED, BLUE);
     Image horizontalGradient = GenImageGradientH(screenWidth, screenHeight, RED, BLUE);
+    Image radialGradient = GenImageRadialGradient(screenWidth, screenHeight, WHITE, BLACK);
     Image checked = GenImageChecked(screenWidth, screenHeight, 32, 32, RED, BLUE);
     Image whiteNoise = GenImageWhiteNoise(screenWidth, screenHeight, 0.5f);
+    Image perlinNoise = GenImagePerlinNoise(screenWidth, screenHeight, 8.f);
     Image cellular = GenImageCellular(screenWidth, screenHeight, 32);
 
     Texture2D textures[TEXTURES_NUM];
     textures[0] = LoadTextureFromImage(verticalGradient);
     textures[1] = LoadTextureFromImage(horizontalGradient);
-    textures[2] = LoadTextureFromImage(checked);
-    textures[3] = LoadTextureFromImage(whiteNoise);
-    textures[4] = LoadTextureFromImage(cellular);
+    textures[2] = LoadTextureFromImage(radialGradient);
+    textures[3] = LoadTextureFromImage(checked);
+    textures[4] = LoadTextureFromImage(whiteNoise);
+    textures[5] = LoadTextureFromImage(perlinNoise);
+    textures[6] = LoadTextureFromImage(cellular);
 
     int currentTexture = 0;
 

src/external/stb_perlin.h

@@ -0,0 +1,316 @@
+// stb_perlin.h - v0.3 - perlin noise
+// public domain single-file C implementation by Sean Barrett
+//
+// LICENSE
+//
+//   See end of file.
+//
+//
+// to create the implementation,
+//     #define STB_PERLIN_IMPLEMENTATION
+// in *one* C/CPP file that includes this file.
+//
+//
+// Documentation:
+//
+// float  stb_perlin_noise3( float x,
+//                           float y,
+//                           float z,
+//                           int   x_wrap=0,
+//                           int   y_wrap=0,
+//                           int   z_wrap=0)
+//
+// This function computes a random value at the coordinate (x,y,z).
+// Adjacent random values are continuous but the noise fluctuates
+// its randomness with period 1, i.e. takes on wholly unrelated values
+// at integer points. Specifically, this implements Ken Perlin's
+// revised noise function from 2002.
+//
+// The "wrap" parameters can be used to create wraparound noise that
+// wraps at powers of two. The numbers MUST be powers of two. Specify
+// 0 to mean "don't care". (The noise always wraps every 256 due
+// details of the implementation, even if you ask for larger or no
+// wrapping.)
+//
+// Fractal Noise:
+//
+// Three common fractal noise functions are included, which produce 
+// a wide variety of nice effects depending on the parameters 
+// provided. Note that each function will call stb_perlin_noise3 
+// 'octaves' times, so this parameter will affect runtime.
+//
+// float stb_perlin_ridge_noise3(float x, float y, float z,
+//                               float lacunarity, float gain, float offset, int octaves,
+//                               int x_wrap, int y_wrap, int z_wrap);
+//
+// float stb_perlin_fbm_noise3(float x, float y, float z,
+//                             float lacunarity, float gain, int octaves,
+//                             int x_wrap, int y_wrap, int z_wrap);
+//
+// float stb_perlin_turbulence_noise3(float x, float y, float z,
+//                                    float lacunarity, float gain,int octaves,
+//                                    int x_wrap, int y_wrap, int z_wrap);
+//
+// Typical values to start playing with:
+//     octaves    =   6     -- number of "octaves" of noise3() to sum
+//     lacunarity = ~ 2.0   -- spacing between successive octaves (use exactly 2.0 for wrapping output)
+//     gain       =   0.5   -- relative weighting applied to each successive octave
+//     offset     =   1.0?  -- used to invert the ridges, may need to be larger, not sure
+//    
+//
+// Contributors:
+//    Jack Mott - additional noise functions
+//
+
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+extern float stb_perlin_noise3(float x, float y, float z, int x_wrap, int y_wrap, int z_wrap);
+extern float stb_perlin_ridge_noise3(float x, float y, float z,float lacunarity, float gain, float offset, int octaves,int x_wrap, int y_wrap, int z_wrap);
+extern float stb_perlin_fbm_noise3(float x, float y, float z,float lacunarity, float gain, int octaves,int x_wrap, int y_wrap, int z_wrap);
+extern float stb_perlin_turbulence_noise3(float x, float y, float z, float lacunarity, float gain, int octaves,int x_wrap, int y_wrap, int z_wrap);
+#ifdef __cplusplus
+}
+#endif
+
+#ifdef STB_PERLIN_IMPLEMENTATION
+
+// not same permutation table as Perlin's reference to avoid copyright issues;
+// Perlin's table can be found at http://mrl.nyu.edu/~perlin/noise/
+// @OPTIMIZE: should this be unsigned char instead of int for cache?
+static unsigned char stb__perlin_randtab[512] =
+{
+   23, 125, 161, 52, 103, 117, 70, 37, 247, 101, 203, 169, 124, 126, 44, 123, 
+   152, 238, 145, 45, 171, 114, 253, 10, 192, 136, 4, 157, 249, 30, 35, 72, 
+   175, 63, 77, 90, 181, 16, 96, 111, 133, 104, 75, 162, 93, 56, 66, 240, 
+   8, 50, 84, 229, 49, 210, 173, 239, 141, 1, 87, 18, 2, 198, 143, 57, 
+   225, 160, 58, 217, 168, 206, 245, 204, 199, 6, 73, 60, 20, 230, 211, 233, 
+   94, 200, 88, 9, 74, 155, 33, 15, 219, 130, 226, 202, 83, 236, 42, 172, 
+   165, 218, 55, 222, 46, 107, 98, 154, 109, 67, 196, 178, 127, 158, 13, 243, 
+   65, 79, 166, 248, 25, 224, 115, 80, 68, 51, 184, 128, 232, 208, 151, 122, 
+   26, 212, 105, 43, 179, 213, 235, 148, 146, 89, 14, 195, 28, 78, 112, 76, 
+   250, 47, 24, 251, 140, 108, 186, 190, 228, 170, 183, 139, 39, 188, 244, 246, 
+   132, 48, 119, 144, 180, 138, 134, 193, 82, 182, 120, 121, 86, 220, 209, 3, 
+   91, 241, 149, 85, 205, 150, 113, 216, 31, 100, 41, 164, 177, 214, 153, 231, 
+   38, 71, 185, 174, 97, 201, 29, 95, 7, 92, 54, 254, 191, 118, 34, 221, 
+   131, 11, 163, 99, 234, 81, 227, 147, 156, 176, 17, 142, 69, 12, 110, 62, 
+   27, 255, 0, 194, 59, 116, 242, 252, 19, 21, 187, 53, 207, 129, 64, 135, 
+   61, 40, 167, 237, 102, 223, 106, 159, 197, 189, 215, 137, 36, 32, 22, 5,  
+
+   // and a second copy so we don't need an extra mask or static initializer
+   23, 125, 161, 52, 103, 117, 70, 37, 247, 101, 203, 169, 124, 126, 44, 123, 
+   152, 238, 145, 45, 171, 114, 253, 10, 192, 136, 4, 157, 249, 30, 35, 72, 
+   175, 63, 77, 90, 181, 16, 96, 111, 133, 104, 75, 162, 93, 56, 66, 240, 
+   8, 50, 84, 229, 49, 210, 173, 239, 141, 1, 87, 18, 2, 198, 143, 57, 
+   225, 160, 58, 217, 168, 206, 245, 204, 199, 6, 73, 60, 20, 230, 211, 233, 
+   94, 200, 88, 9, 74, 155, 33, 15, 219, 130, 226, 202, 83, 236, 42, 172, 
+   165, 218, 55, 222, 46, 107, 98, 154, 109, 67, 196, 178, 127, 158, 13, 243, 
+   65, 79, 166, 248, 25, 224, 115, 80, 68, 51, 184, 128, 232, 208, 151, 122, 
+   26, 212, 105, 43, 179, 213, 235, 148, 146, 89, 14, 195, 28, 78, 112, 76, 
+   250, 47, 24, 251, 140, 108, 186, 190, 228, 170, 183, 139, 39, 188, 244, 246, 
+   132, 48, 119, 144, 180, 138, 134, 193, 82, 182, 120, 121, 86, 220, 209, 3, 
+   91, 241, 149, 85, 205, 150, 113, 216, 31, 100, 41, 164, 177, 214, 153, 231, 
+   38, 71, 185, 174, 97, 201, 29, 95, 7, 92, 54, 254, 191, 118, 34, 221, 
+   131, 11, 163, 99, 234, 81, 227, 147, 156, 176, 17, 142, 69, 12, 110, 62, 
+   27, 255, 0, 194, 59, 116, 242, 252, 19, 21, 187, 53, 207, 129, 64, 135, 
+   61, 40, 167, 237, 102, 223, 106, 159, 197, 189, 215, 137, 36, 32, 22, 5,  
+};
+
+static float stb__perlin_lerp(float a, float b, float t)
+{
+   return a + (b-a) * t;
+}
+
+static int stb__perlin_fastfloor(float a)
+{
+	int ai = (int) a;
+	return (a < ai) ? ai-1 : ai;
+}
+
+// different grad function from Perlin's, but easy to modify to match reference
+static float stb__perlin_grad(int hash, float x, float y, float z)
+{
+   static float basis[12][4] =
+   {
+      {  1, 1, 0 },
+      { -1, 1, 0 },
+      {  1,-1, 0 },
+      { -1,-1, 0 },
+      {  1, 0, 1 },
+      { -1, 0, 1 },
+      {  1, 0,-1 },
+      { -1, 0,-1 },
+      {  0, 1, 1 },
+      {  0,-1, 1 },
+      {  0, 1,-1 },
+      {  0,-1,-1 },
+   };
+
+   // perlin's gradient has 12 cases so some get used 1/16th of the time
+   // and some 2/16ths. We reduce bias by changing those fractions
+   // to 5/64ths and 6/64ths, and the same 4 cases get the extra weight.
+   static unsigned char indices[64] =
+   {
+      0,1,2,3,4,5,6,7,8,9,10,11,
+      0,9,1,11,
+      0,1,2,3,4,5,6,7,8,9,10,11,
+      0,1,2,3,4,5,6,7,8,9,10,11,
+      0,1,2,3,4,5,6,7,8,9,10,11,
+      0,1,2,3,4,5,6,7,8,9,10,11,
+   };
+
+   // if you use reference permutation table, change 63 below to 15 to match reference
+   // (this is why the ordering of the table above is funky)
+   float *grad = basis[indices[hash & 63]];
+   return grad[0]*x + grad[1]*y + grad[2]*z;
+}
+
+float stb_perlin_noise3(float x, float y, float z, int x_wrap, int y_wrap, int z_wrap)
+{
+   float u,v,w;
+   float n000,n001,n010,n011,n100,n101,n110,n111;
+   float n00,n01,n10,n11;
+   float n0,n1;
+
+   unsigned int x_mask = (x_wrap-1) & 255;
+   unsigned int y_mask = (y_wrap-1) & 255;
+   unsigned int z_mask = (z_wrap-1) & 255;
+   int px = stb__perlin_fastfloor(x);
+   int py = stb__perlin_fastfloor(y);
+   int pz = stb__perlin_fastfloor(z);
+   int x0 = px & x_mask, x1 = (px+1) & x_mask;
+   int y0 = py & y_mask, y1 = (py+1) & y_mask;
+   int z0 = pz & z_mask, z1 = (pz+1) & z_mask;
+   int r0,r1, r00,r01,r10,r11;
+
+   #define stb__perlin_ease(a)   (((a*6-15)*a + 10) * a * a * a)
+
+   x -= px; u = stb__perlin_ease(x);
+   y -= py; v = stb__perlin_ease(y);
+   z -= pz; w = stb__perlin_ease(z);
+
+   r0 = stb__perlin_randtab[x0];
+   r1 = stb__perlin_randtab[x1];
+
+   r00 = stb__perlin_randtab[r0+y0];
+   r01 = stb__perlin_randtab[r0+y1];
+   r10 = stb__perlin_randtab[r1+y0];
+   r11 = stb__perlin_randtab[r1+y1];
+
+   n000 = stb__perlin_grad(stb__perlin_randtab[r00+z0], x  , y  , z   );
+   n001 = stb__perlin_grad(stb__perlin_randtab[r00+z1], x  , y  , z-1 );
+   n010 = stb__perlin_grad(stb__perlin_randtab[r01+z0], x  , y-1, z   );
+   n011 = stb__perlin_grad(stb__perlin_randtab[r01+z1], x  , y-1, z-1 );
+   n100 = stb__perlin_grad(stb__perlin_randtab[r10+z0], x-1, y  , z   );
+   n101 = stb__perlin_grad(stb__perlin_randtab[r10+z1], x-1, y  , z-1 );
+   n110 = stb__perlin_grad(stb__perlin_randtab[r11+z0], x-1, y-1, z   );
+   n111 = stb__perlin_grad(stb__perlin_randtab[r11+z1], x-1, y-1, z-1 );
+
+   n00 = stb__perlin_lerp(n000,n001,w);
+   n01 = stb__perlin_lerp(n010,n011,w);
+   n10 = stb__perlin_lerp(n100,n101,w);
+   n11 = stb__perlin_lerp(n110,n111,w);
+
+   n0 = stb__perlin_lerp(n00,n01,v);
+   n1 = stb__perlin_lerp(n10,n11,v);
+
+   return stb__perlin_lerp(n0,n1,u);
+}
+
+float stb_perlin_ridge_noise3(float x, float y, float z,float lacunarity, float gain, float offset, int octaves,int x_wrap, int y_wrap, int z_wrap)
+{
+   int i;
+   float frequency = 1.0f;
+   float prev = 1.0f;
+   float amplitude = 0.5f;
+   float sum = 0.0f;
+
+   for (i = 0; i < octaves; i++) {
+      float r = (float)(stb_perlin_noise3(x*frequency,y*frequency,z*frequency,x_wrap,y_wrap,z_wrap));
+      r = r<0 ? -r : r; // fabs()
+      r = offset - r;
+      r = r*r;
+      sum += r*amplitude*prev;
+      prev = r;
+      frequency *= lacunarity;
+      amplitude *= gain;
+   }
+   return sum;
+}
+
+float stb_perlin_fbm_noise3(float x, float y, float z,float lacunarity, float gain, int octaves,int x_wrap, int y_wrap, int z_wrap)
+{
+   int i;
+   float frequency = 1.0f;
+   float amplitude = 1.0f;
+   float sum = 0.0f;
+   
+   for (i = 0; i < octaves; i++) {
+      sum += stb_perlin_noise3(x*frequency,y*frequency,z*frequency,x_wrap,y_wrap,z_wrap)*amplitude;
+      frequency *= lacunarity;
+      amplitude *= gain;
+   }
+   return sum;
+}
+
+float stb_perlin_turbulence_noise3(float x, float y, float z, float lacunarity, float gain, int octaves,int x_wrap, int y_wrap, int z_wrap)
+{
+   int i;
+   float frequency = 1.0f;
+   float amplitude = 1.0f;
+   float sum = 0.0f;
+   
+   for (i = 0; i < octaves; i++) {
+      float r = stb_perlin_noise3(x*frequency,y*frequency,z*frequency,x_wrap,y_wrap,z_wrap)*amplitude;
+      r = r<0 ? -r : r; // fabs()
+      sum += r;
+      frequency *= lacunarity;
+      amplitude *= gain;
+   }
+   return sum;
+}
+
+#endif  // STB_PERLIN_IMPLEMENTATION
+
+/*
+------------------------------------------------------------------------------
+This software is available under 2 licenses -- choose whichever you prefer.
+------------------------------------------------------------------------------
+ALTERNATIVE A - MIT License
+Copyright (c) 2017 Sean Barrett
+Permission is hereby granted, free of charge, to any person obtaining a copy of 
+this software and associated documentation files (the "Software"), to deal in 
+the Software without restriction, including without limitation the rights to 
+use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies 
+of the Software, and to permit persons to whom the Software is furnished to do 
+so, subject to the following conditions:
+The above copyright notice and this permission notice shall be included in all 
+copies or substantial portions of the Software.
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE 
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER 
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, 
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE 
+SOFTWARE.
+------------------------------------------------------------------------------
+ALTERNATIVE B - Public Domain (www.unlicense.org)
+This is free and unencumbered software released into the public domain.
+Anyone is free to copy, modify, publish, use, compile, sell, or distribute this 
+software, either in source code form or as a compiled binary, for any purpose, 
+commercial or non-commercial, and by any means.
+In jurisdictions that recognize copyright laws, the author or authors of this 
+software dedicate any and all copyright interest in the software to the public 
+domain. We make this dedication for the benefit of the public at large and to 
+the detriment of our heirs and successors. We intend this dedication to be an 
+overt act of relinquishment in perpetuity of all present and future rights to 
+this software under copyright law.
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE 
+AUTHORS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN 
+ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION 
+WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+------------------------------------------------------------------------------
+*/

src/raylib.h

@@ -876,8 +876,10 @@ RLAPI void ImageColorBrightness(Image *image, int brightness);
 // Image generation functions
 RLAPI Image GenImageGradientV(int width, int height, Color top, Color bottom);                           // Generate image: vertical gradient
 RLAPI Image GenImageGradientH(int width, int height, Color left, Color right);                           // Generate image: horizontal gradient
+RLAPI Image GenImageRadialGradient(int width, int height, Color inner, Color outer);                     // Generate image: radial gradient
 RLAPI Image GenImageChecked(int width, int height, int checksX, int checksY, Color col1, Color col2);    // Generate image: checked
 RLAPI Image GenImageWhiteNoise(int width, int height, float factor);                                     // Generate image: white noise
+RLAPI Image GenImagePerlinNoise(int width, int height, float scale);                                     // Generate image: perlin noise
 RLAPI Image GenImageCellular(int width, int height, int tileSize);                                       // Generate image: cellular algorithm. Bigger tileSize means bigger cells
 
 // Texture2D configuration functions

src/textures.c

@@ -68,6 +68,9 @@
 
 #include "utils.h"              // Required for: fopen() Android mapping
 
+#define STB_PERLIN_IMPLEMENTATION
+#include "external/stb_perlin.h"// Required for: stb_perlin_fbm_noise3
+
 // Support only desired texture formats on stb_image
 #if !defined(SUPPORT_FILEFORMAT_BMP)
     #define STBI_NO_BMP
@@ -1477,6 +1480,34 @@ Image GenImageGradientH(int width, int height, Color left, Color right)
     return image;
 }
 
+// Generate image: radial gradient
+Image GenImageRadialGradient(int width, int height, Color inner, Color outer)
+{
+    Color *pixels = (Color*)malloc(width * height * sizeof(Color));
+    float radius = (width < height) ? (float)width / 2.f : (float)height / 2.f;
+
+    float center_x = (float)width / 2.f;
+    float center_y = (float)height / 2.f;
+    for (int y = 0; y < height; y++)
+    {
+        for (int x = 0; x < width; x++)
+        {
+            float dist = hypotf((float)x - center_x, (float)y - center_y);
+            float factor = dist / radius;
+            factor = fmin(factor, 1.f); // dist can be bigger than radius so we have to check
+            pixels[y*width + x].r = (int)((float)outer.r * factor + (float)inner.r * (1.f - factor));
+            pixels[y*width + x].g = (int)((float)outer.g * factor + (float)inner.g * (1.f - factor));
+            pixels[y*width + x].b = (int)((float)outer.b * factor + (float)inner.b * (1.f - factor));
+            pixels[y*width + x].a = (int)((float)outer.a * factor + (float)inner.a * (1.f - factor));
+        }
+    }
+
+    Image image = LoadImageEx(pixels, width, height);
+    free(pixels);
+
+    return image;
+}
+
 // Generate image: checked
 Image GenImageChecked(int width, int height, int checksX, int checksY, Color col1, Color col2)
 {
@@ -1514,6 +1545,30 @@ Image GenImageWhiteNoise(int width, int height, float factor)
     return image;
 }
 
+// Generate image: perlin noise
+Image GenImagePerlinNoise(int width, int height, float scale)
+{
+    Color *pixels = (Color*)malloc(width * height * sizeof(Color));
+
+    for (int y = 0; y < height; y++)
+    {
+        for (int x = 0; x < width; x++)
+        {
+            float nx = (float)x * scale / (float)width;
+            float ny = (float)y * scale / (float)height;
+            // we need to translate the data from [-1; 1] to [0; 1]
+            float p = (stb_perlin_fbm_noise3(nx, ny, 1.f, 2.f, 0.5f, 6, 0, 0, 0) + 1.f) / 2.f;
+            int intensity = (int)(p * 255.f);
+            pixels[y*width + x] = (Color){intensity, intensity, intensity, 255};
+        }
+    }
+
+    Image image = LoadImageEx(pixels, width, height);
+    free(pixels);
+
+    return image;
+}
+
 // Generate image: cellular algorithm. Bigger tileSize means bigger cells
 Image GenImageCellular(int width, int height, int tileSize)
 {