paysages : Added naive noise function.

git-svn-id: https://subversion.assembla.com/svn/thunderk/paysages@426 b1fd45b6-86a6-48da-8261-f70d1f35bdcc

TODO

@@ -2,7 +2,6 @@ Technology Preview 2 :
 - Fully move layer management from BaseForm to BaseFormLayer.
 - Replace math.h methods by optimized ones (fastfloor, fastsin...).
 - Reimplement perlin noise and custom noise.
-- Add ridged noise option (with configurable ridge offset and direction).
 - Replace terrain canvas editor by full sculpting editor.
    => Add a generation dialog, with fixed resolution.
    => Store local terrain modifications in fully dynamic canvas.

lib_paysages/noise.c

@@ -6,6 +6,7 @@
 
 #include "tools.h"
 #include "noisesimplex.h"
+#include "noisenaive.h"
 
 #define MAX_LEVEL_COUNT 30
 
@@ -27,20 +28,22 @@ struct NoiseGenerator
 void noiseInit()
 {
     noiseSimplexInit();
+    noiseNaiveInit();
 }
 
 void noiseQuit()
 {
+    noiseNaiveQuit();
 }
 
 void noiseSave(PackStream* stream)
 {
-    UNUSED(stream);
+    noiseNaiveSave(stream);
 }
 
 void noiseLoad(PackStream* stream)
 {
-    UNUSED(stream);
+    noiseNaiveLoad(stream);
 }
 
 NoiseGenerator* noiseCreateGenerator()
@@ -144,6 +147,9 @@ void noiseValidate(NoiseGenerator* generator)
         break;
     case NOISE_FUNCTION_NAIVE:
         /* TODO */
+        generator->_func_noise_1d = noiseNaiveGet1DValue;
+        generator->_func_noise_2d = noiseNaiveGet2DValue;
+        generator->_func_noise_3d = noiseNaiveGet3DValue;
         break;
     }
     

lib_paysages/noisenaive.c

@@ -0,0 +1,366 @@
+#include "noisenaive.h"
+
+/*
+ * Naive noise implementation, based on pseudo-random grids.
+ */
+
+#include <stdlib.h>
+#include <math.h>
+#include <string.h>
+#include "tools.h"
+
+static int _noise_pool_size;
+static double* _noise_pool;
+
+void noiseNaiveInit()
+{
+    int i;
+    
+    _noise_pool_size = 1048576;
+    _noise_pool = malloc(sizeof(double) * _noise_pool_size);
+
+    for (i = 0; i < _noise_pool_size; i++)
+    {
+        _noise_pool[i] = toolsRandom() - 0.5;
+    }
+}
+
+void noiseNaiveQuit()
+{
+    free(_noise_pool);
+}
+
+void noiseNaiveSave(PackStream* stream)
+{
+    int i;
+    
+    packWriteInt(stream, &_noise_pool_size);
+    for (i = 0; i < _noise_pool_size; i++)
+    {
+        packWriteDouble(stream, _noise_pool + i);
+    }
+}
+
+void noiseNaiveLoad(PackStream* stream)
+{
+    int i;
+    
+    packReadInt(stream, &_noise_pool_size);
+    _noise_pool = realloc(_noise_pool, sizeof(double) * _noise_pool_size);
+    for (i = 0; i < _noise_pool_size; i++)
+    {
+        packReadDouble(stream, _noise_pool + i);
+    }
+}
+
+double noiseNaiveGet1DValue(double x)
+{
+    int size = _noise_pool_size;
+
+    int xbase = (int)floor(x);
+
+    double xinternal = x - (double)xbase;
+
+    int x0 = (xbase - 1) % size;
+    if (x0 < 0)
+    {
+        x0 += size;
+    }
+    int x1 = xbase % size;
+    if (x1 < 0)
+    {
+        x1 += size;
+    }
+    int x2 = (xbase + 1) % size;
+    if (x2 < 0)
+    {
+        x2 += size;
+    }
+    int x3 = (xbase + 2) % size;
+    if (x3 < 0)
+    {
+        x3 += size;
+    }
+
+    double buf_cubic_x[4];
+
+    buf_cubic_x[0] = _noise_pool[x0 % _noise_pool_size];
+    buf_cubic_x[1] = _noise_pool[x1 % _noise_pool_size];
+    buf_cubic_x[2] = _noise_pool[x2 % _noise_pool_size];
+    buf_cubic_x[3] = _noise_pool[x3 % _noise_pool_size];
+
+    return toolsCubicInterpolate(buf_cubic_x, xinternal);
+}
+
+double noiseNaiveGet2DValue(double x, double y)
+{
+    int size = (int)pow(_noise_pool_size, 0.5);
+
+    int xbase = (int)floor(x);
+    int ybase = (int)floor(y);
+
+    double xinternal = x - (double)xbase;
+    double yinternal = y - (double)ybase;
+
+    int x0 = (xbase - 1) % size;
+    if (x0 < 0)
+    {
+        x0 += size;
+    }
+    int x1 = xbase % size;
+    if (x1 < 0)
+    {
+        x1 += size;
+    }
+    int x2 = (xbase + 1) % size;
+    if (x2 < 0)
+    {
+        x2 += size;
+    }
+    int x3 = (xbase + 2) % size;
+    if (x3 < 0)
+    {
+        x3 += size;
+    }
+
+    int y0 = (ybase - 1) % size;
+    if (y0 < 0)
+    {
+        y0 += size;
+    }
+    int y1 = ybase % size;
+    if (y1 < 0)
+    {
+        y1 += size;
+    }
+    int y2 = (ybase + 1) % size;
+    if (y2 < 0)
+    {
+        y2 += size;
+    }
+    int y3 = (ybase + 2) % size;
+    if (y3 < 0)
+    {
+        y3 += size;
+    }
+
+    double buf_cubic_x[4];
+    double buf_cubic_y[4];
+
+    buf_cubic_x[0] = _noise_pool[(y0 * size + x0) % _noise_pool_size];
+    buf_cubic_x[1] = _noise_pool[(y0 * size + x1) % _noise_pool_size];
+    buf_cubic_x[2] = _noise_pool[(y0 * size + x2) % _noise_pool_size];
+    buf_cubic_x[3] = _noise_pool[(y0 * size + x3) % _noise_pool_size];
+    buf_cubic_y[0] = toolsCubicInterpolate(buf_cubic_x, xinternal);
+
+    buf_cubic_x[0] = _noise_pool[(y1 * size + x0) % _noise_pool_size];
+    buf_cubic_x[1] = _noise_pool[(y1 * size + x1) % _noise_pool_size];
+    buf_cubic_x[2] = _noise_pool[(y1 * size + x2) % _noise_pool_size];
+    buf_cubic_x[3] = _noise_pool[(y1 * size + x3) % _noise_pool_size];
+    buf_cubic_y[1] = toolsCubicInterpolate(buf_cubic_x, xinternal);
+
+    buf_cubic_x[0] = _noise_pool[(y2 * size + x0) % _noise_pool_size];
+    buf_cubic_x[1] = _noise_pool[(y2 * size + x1) % _noise_pool_size];
+    buf_cubic_x[2] = _noise_pool[(y2 * size + x2) % _noise_pool_size];
+    buf_cubic_x[3] = _noise_pool[(y2 * size + x3) % _noise_pool_size];
+    buf_cubic_y[2] = toolsCubicInterpolate(buf_cubic_x, xinternal);
+
+    buf_cubic_x[0] = _noise_pool[(y3 * size + x0) % _noise_pool_size];
+    buf_cubic_x[1] = _noise_pool[(y3 * size + x1) % _noise_pool_size];
+    buf_cubic_x[2] = _noise_pool[(y3 * size + x2) % _noise_pool_size];
+    buf_cubic_x[3] = _noise_pool[(y3 * size + x3) % _noise_pool_size];
+    buf_cubic_y[3] = toolsCubicInterpolate(buf_cubic_x, xinternal);
+
+    return toolsCubicInterpolate(buf_cubic_y, yinternal);
+}
+
+double noiseNaiveGet3DValue(double x, double y, double z)
+{
+    int size = (int)pow(_noise_pool_size, 0.33333333333333333);
+
+    int xbase = (int)floor(x);
+    int ybase = (int)floor(y);
+    int zbase = (int)floor(z);
+
+    double xinternal = x - (double)xbase;
+    double yinternal = y - (double)ybase;
+    double zinternal = z - (double)zbase;
+
+    int x0 = (xbase - 1) % size;
+    if (x0 < 0)
+    {
+        x0 += size;
+    }
+    int x1 = xbase % size;
+    if (x1 < 0)
+    {
+        x1 += size;
+    }
+    int x2 = (xbase + 1) % size;
+    if (x2 < 0)
+    {
+        x2 += size;
+    }
+    int x3 = (xbase + 2) % size;
+    if (x3 < 0)
+    {
+        x3 += size;
+    }
+
+    int y0 = (ybase - 1) % size;
+    if (y0 < 0)
+    {
+        y0 += size;
+    }
+    int y1 = ybase % size;
+    if (y1 < 0)
+    {
+        y1 += size;
+    }
+    int y2 = (ybase + 1) % size;
+    if (y2 < 0)
+    {
+        y2 += size;
+    }
+    int y3 = (ybase + 2) % size;
+    if (y3 < 0)
+    {
+        y3 += size;
+    }
+
+    int z0 = (zbase - 1) % size;
+    if (z0 < 0)
+    {
+        z0 += size;
+    }
+    int z1 = zbase % size;
+    if (z1 < 0)
+    {
+        z1 += size;
+    }
+    int z2 = (zbase + 1) % size;
+    if (z2 < 0)
+    {
+        z2 += size;
+    }
+    int z3 = (zbase + 2) % size;
+    if (z3 < 0)
+    {
+        z3 += size;
+    }
+
+    double buf_cubic_x[4];
+    double buf_cubic_y[4];
+    double buf_cubic_z[4];
+
+    buf_cubic_x[0] = _noise_pool[(y0 * size * size + x0 * size + z0) % _noise_pool_size];
+    buf_cubic_x[1] = _noise_pool[(y0 * size * size + x1 * size + z0) % _noise_pool_size];
+    buf_cubic_x[2] = _noise_pool[(y0 * size * size + x2 * size + z0) % _noise_pool_size];
+    buf_cubic_x[3] = _noise_pool[(y0 * size * size + x3 * size + z0) % _noise_pool_size];
+    buf_cubic_y[0] = toolsCubicInterpolate(buf_cubic_x, xinternal);
+
+    buf_cubic_x[0] = _noise_pool[(y1 * size * size + x0 * size + z0) % _noise_pool_size];
+    buf_cubic_x[1] = _noise_pool[(y1 * size * size + x1 * size + z0) % _noise_pool_size];
+    buf_cubic_x[2] = _noise_pool[(y1 * size * size + x2 * size + z0) % _noise_pool_size];
+    buf_cubic_x[3] = _noise_pool[(y1 * size * size + x3 * size + z0) % _noise_pool_size];
+    buf_cubic_y[1] = toolsCubicInterpolate(buf_cubic_x, xinternal);
+
+    buf_cubic_x[0] = _noise_pool[(y2 * size * size + x0 * size + z0) % _noise_pool_size];
+    buf_cubic_x[1] = _noise_pool[(y2 * size * size + x1 * size + z0) % _noise_pool_size];
+    buf_cubic_x[2] = _noise_pool[(y2 * size * size + x2 * size + z0) % _noise_pool_size];
+    buf_cubic_x[3] = _noise_pool[(y2 * size * size + x3 * size + z0) % _noise_pool_size];
+    buf_cubic_y[2] = toolsCubicInterpolate(buf_cubic_x, xinternal);
+
+    buf_cubic_x[0] = _noise_pool[(y3 * size * size + x0 * size + z0) % _noise_pool_size];
+    buf_cubic_x[1] = _noise_pool[(y3 * size * size + x1 * size + z0) % _noise_pool_size];
+    buf_cubic_x[2] = _noise_pool[(y3 * size * size + x2 * size + z0) % _noise_pool_size];
+    buf_cubic_x[3] = _noise_pool[(y3 * size * size + x3 * size + z0) % _noise_pool_size];
+    buf_cubic_y[3] = toolsCubicInterpolate(buf_cubic_x, xinternal);
+
+    buf_cubic_z[0] =  toolsCubicInterpolate(buf_cubic_y, yinternal);
+
+    buf_cubic_x[0] = _noise_pool[(y0 * size * size + x0 * size + z1) % _noise_pool_size];
+    buf_cubic_x[1] = _noise_pool[(y0 * size * size + x1 * size + z1) % _noise_pool_size];
+    buf_cubic_x[2] = _noise_pool[(y0 * size * size + x2 * size + z1) % _noise_pool_size];
+    buf_cubic_x[3] = _noise_pool[(y0 * size * size + x3 * size + z1) % _noise_pool_size];
+    buf_cubic_y[0] = toolsCubicInterpolate(buf_cubic_x, xinternal);
+
+    buf_cubic_x[0] = _noise_pool[(y1 * size * size + x0 * size + z1) % _noise_pool_size];
+    buf_cubic_x[1] = _noise_pool[(y1 * size * size + x1 * size + z1) % _noise_pool_size];
+    buf_cubic_x[2] = _noise_pool[(y1 * size * size + x2 * size + z1) % _noise_pool_size];
+    buf_cubic_x[3] = _noise_pool[(y1 * size * size + x3 * size + z1) % _noise_pool_size];
+    buf_cubic_y[1] = toolsCubicInterpolate(buf_cubic_x, xinternal);
+
+    buf_cubic_x[0] = _noise_pool[(y2 * size * size + x0 * size + z1) % _noise_pool_size];
+    buf_cubic_x[1] = _noise_pool[(y2 * size * size + x1 * size + z1) % _noise_pool_size];
+    buf_cubic_x[2] = _noise_pool[(y2 * size * size + x2 * size + z1) % _noise_pool_size];
+    buf_cubic_x[3] = _noise_pool[(y2 * size * size + x3 * size + z1) % _noise_pool_size];
+    buf_cubic_y[2] = toolsCubicInterpolate(buf_cubic_x, xinternal);
+
+    buf_cubic_x[0] = _noise_pool[(y3 * size * size + x0 * size + z1) % _noise_pool_size];
+    buf_cubic_x[1] = _noise_pool[(y3 * size * size + x1 * size + z1) % _noise_pool_size];
+    buf_cubic_x[2] = _noise_pool[(y3 * size * size + x2 * size + z1) % _noise_pool_size];
+    buf_cubic_x[3] = _noise_pool[(y3 * size * size + x3 * size + z1) % _noise_pool_size];
+    buf_cubic_y[3] = toolsCubicInterpolate(buf_cubic_x, xinternal);
+
+    buf_cubic_z[1] =  toolsCubicInterpolate(buf_cubic_y, yinternal);
+
+    buf_cubic_x[0] = _noise_pool[(y0 * size * size + x0 * size + z2) % _noise_pool_size];
+    buf_cubic_x[1] = _noise_pool[(y0 * size * size + x1 * size + z2) % _noise_pool_size];
+    buf_cubic_x[2] = _noise_pool[(y0 * size * size + x2 * size + z2) % _noise_pool_size];
+    buf_cubic_x[3] = _noise_pool[(y0 * size * size + x3 * size + z2) % _noise_pool_size];
+    buf_cubic_y[0] = toolsCubicInterpolate(buf_cubic_x, xinternal);
+
+    buf_cubic_x[0] = _noise_pool[(y1 * size * size + x0 * size + z2) % _noise_pool_size];
+    buf_cubic_x[1] = _noise_pool[(y1 * size * size + x1 * size + z2) % _noise_pool_size];
+    buf_cubic_x[2] = _noise_pool[(y1 * size * size + x2 * size + z2) % _noise_pool_size];
+    buf_cubic_x[3] = _noise_pool[(y1 * size * size + x3 * size + z2) % _noise_pool_size];
+    buf_cubic_y[1] = toolsCubicInterpolate(buf_cubic_x, xinternal);
+
+    buf_cubic_x[0] = _noise_pool[(y2 * size * size + x0 * size + z2) % _noise_pool_size];
+    buf_cubic_x[1] = _noise_pool[(y2 * size * size + x1 * size + z2) % _noise_pool_size];
+    buf_cubic_x[2] = _noise_pool[(y2 * size * size + x2 * size + z2) % _noise_pool_size];
+    buf_cubic_x[3] = _noise_pool[(y2 * size * size + x3 * size + z2) % _noise_pool_size];
+    buf_cubic_y[2] = toolsCubicInterpolate(buf_cubic_x, xinternal);
+
+    buf_cubic_x[0] = _noise_pool[(y3 * size * size + x0 * size + z2) % _noise_pool_size];
+    buf_cubic_x[1] = _noise_pool[(y3 * size * size + x1 * size + z2) % _noise_pool_size];
+    buf_cubic_x[2] = _noise_pool[(y3 * size * size + x2 * size + z2) % _noise_pool_size];
+    buf_cubic_x[3] = _noise_pool[(y3 * size * size + x3 * size + z2) % _noise_pool_size];
+    buf_cubic_y[3] = toolsCubicInterpolate(buf_cubic_x, xinternal);
+
+    buf_cubic_z[2] =  toolsCubicInterpolate(buf_cubic_y, yinternal);
+
+    buf_cubic_x[0] = _noise_pool[(y0 * size * size + x0 * size + z3) % _noise_pool_size];
+    buf_cubic_x[1] = _noise_pool[(y0 * size * size + x1 * size + z3) % _noise_pool_size];
+    buf_cubic_x[2] = _noise_pool[(y0 * size * size + x2 * size + z3) % _noise_pool_size];
+    buf_cubic_x[3] = _noise_pool[(y0 * size * size + x3 * size + z3) % _noise_pool_size];
+    buf_cubic_y[0] = toolsCubicInterpolate(buf_cubic_x, xinternal);
+
+    buf_cubic_x[0] = _noise_pool[(y1 * size * size + x0 * size + z3) % _noise_pool_size];
+    buf_cubic_x[1] = _noise_pool[(y1 * size * size + x1 * size + z3) % _noise_pool_size];
+    buf_cubic_x[2] = _noise_pool[(y1 * size * size + x2 * size + z3) % _noise_pool_size];
+    buf_cubic_x[3] = _noise_pool[(y1 * size * size + x3 * size + z3) % _noise_pool_size];
+    buf_cubic_y[1] = toolsCubicInterpolate(buf_cubic_x, xinternal);
+
+    buf_cubic_x[0] = _noise_pool[(y2 * size * size + x0 * size + z3) % _noise_pool_size];
+    buf_cubic_x[1] = _noise_pool[(y2 * size * size + x1 * size + z3) % _noise_pool_size];
+    buf_cubic_x[2] = _noise_pool[(y2 * size * size + x2 * size + z3) % _noise_pool_size];
+    buf_cubic_x[3] = _noise_pool[(y2 * size * size + x3 * size + z3) % _noise_pool_size];
+    buf_cubic_y[2] = toolsCubicInterpolate(buf_cubic_x, xinternal);
+
+    buf_cubic_x[0] = _noise_pool[(y3 * size * size + x0 * size + z3) % _noise_pool_size];
+    buf_cubic_x[1] = _noise_pool[(y3 * size * size + x1 * size + z3) % _noise_pool_size];
+    buf_cubic_x[2] = _noise_pool[(y3 * size * size + x2 * size + z3) % _noise_pool_size];
+    buf_cubic_x[3] = _noise_pool[(y3 * size * size + x3 * size + z3) % _noise_pool_size];
+    buf_cubic_y[3] = toolsCubicInterpolate(buf_cubic_x, xinternal);
+
+    buf_cubic_z[3] =  toolsCubicInterpolate(buf_cubic_y, yinternal);
+
+    return toolsCubicInterpolate(buf_cubic_z, zinternal);
+}
+
+/*double noiseNaiveGet4DValue(double x, double y, double z, double w)
+{
+    
+}*/

lib_paysages/noisenaive.h

@@ -0,0 +1,23 @@
+#ifndef _PAYSAGES_NOISENAIVE_H_
+#define _PAYSAGES_NOISENAIVE_H_
+
+#include "pack.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+void noiseNaiveInit();
+void noiseNaiveQuit();
+void noiseNaiveSave(PackStream* stream);
+void noiseNaiveLoad(PackStream* stream);
+double noiseNaiveGet1DValue(double x);
+double noiseNaiveGet2DValue(double x, double y);
+double noiseNaiveGet3DValue(double x, double y, double z);
+/*double noiseNaiveGet4DValue(double x, double y, double z, double w);*/
+    
+#ifdef __cplusplus
+}
+#endif
+
+#endif

lib_paysages/noisesimplex.c

@@ -139,24 +139,24 @@ void noiseSimplexInit()
     _G4 = (5.0 - sqrt(5.0)) / 20.0;
 }
 
-double noiseSimplexGet1DValue(double xin)
+double noiseSimplexGet1DValue(double x)
 {
     /* TODO Find custom function */
-    return noiseSimplexGet2DValue(xin, 0.0);
+    return noiseSimplexGet2DValue(x, 0.0);
 }
 
-double noiseSimplexGet2DValue(double xin, double yin)
+double noiseSimplexGet2DValue(double x, double y)
 {
     double n0, n1, n2; /* Noise contributions from the three corners */
     /* Skew the input space to determine which simplex cell we're in */
-    double s = (xin + yin) * _F2; /* Hairy factor for 2D */
+    double s = (x + y) * _F2; /* Hairy factor for 2D */
-    int i = _fastfloor(xin + s);
+    int i = _fastfloor(x + s);
-    int j = _fastfloor(yin + s);
+    int j = _fastfloor(y + s);
     double t = (i + j) * _G2;
     double X0 = i - t; /* Unskew the cell origin back to (x,y) space */
     double Y0 = j - t;
-    double x0 = xin - X0; /* The x,y distances from the cell origin */
+    double x0 = x - X0; /* The x,y distances from the cell origin */
-    double y0 = yin - Y0;
+    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 */
@@ -210,21 +210,21 @@ double noiseSimplexGet2DValue(double xin, double yin)
     return 35.0 * (n0 + n1 + n2);
 }
 
-double noiseSimplexGet3DValue(double xin, double yin, double zin)
+double noiseSimplexGet3DValue(double x, double y, double z)
 {
     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 = (xin + yin + zin) * _F3; /* Very nice and simple skew factor for 3D */
+    double s = (x + y + z) * _F3; /* Very nice and simple skew factor for 3D */
-    int i = _fastfloor(xin + s);
+    int i = _fastfloor(x + s);
-    int j = _fastfloor(yin + s);
+    int j = _fastfloor(y + s);
-    int k = _fastfloor(zin + s);
+    int k = _fastfloor(z + s);
     double t = (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 = xin - X0; /* The x,y,z distances from the cell origin */
+    double x0 = x - X0; /* The x,y,z distances from the cell origin */
-    double y0 = yin - Y0;
+    double y0 = y - Y0;
-    double z0 = zin - Z0;
+    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 */

lib_paysages/noisesimplex.h

@@ -1,14 +1,14 @@
-#ifndef _PAYSAGES_SIMPLEXNOISE_H_
+#ifndef _PAYSAGES_NOISESIMPLEX_H_
-#define _PAYSAGES_SIMPLEXNOISE_H_
+#define _PAYSAGES_NOISESIMPLEX_H_
 
 #ifdef __cplusplus
 extern "C" {
 #endif
 
 void noiseSimplexInit();
-double noiseSimplexGet1DValue(double xin);
+double noiseSimplexGet1DValue(double x);
-double noiseSimplexGet2DValue(double xin, double yin);
+double noiseSimplexGet2DValue(double x, double y);
-double noiseSimplexGet3DValue(double xin, double yin, double zin);
+double noiseSimplexGet3DValue(double x, double y, double z);
 double noiseSimplexGet4DValue(double x, double y, double z, double w);
     
 #ifdef __cplusplus

lib_paysages/tools.c

@@ -13,21 +13,26 @@ double toolsRandom()
     return ((double)rand()) / (double)RAND_MAX;
 }
 
-static inline double __cubicInterpolate(double p[4], double x)
+static inline double _cubicInterpolate(double p[4], double x)
 {
     return p[1] + 0.5 * x * (p[2] - p[0] + x * (2.0 * p[0] - 5.0 * p[1] + 4.0 * p[2] - p[3] + x * (3.0 * (p[1] - p[2]) + p[3] - p[0])));
 }
 
+double toolsCubicInterpolate(double stencil[4], double x)
+{
+    return _cubicInterpolate(stencil, x);
+}
+
 double toolsBicubicInterpolate(double stencil[16], double x, double y)
 {
     double buf_cubic_y[4];
 
-    buf_cubic_y[0] = __cubicInterpolate(stencil, x);
+    buf_cubic_y[0] = _cubicInterpolate(stencil, x);
-    buf_cubic_y[1] = __cubicInterpolate(stencil + 4, x);
+    buf_cubic_y[1] = _cubicInterpolate(stencil + 4, x);
-    buf_cubic_y[2] = __cubicInterpolate(stencil + 8, x);
+    buf_cubic_y[2] = _cubicInterpolate(stencil + 8, x);
-    buf_cubic_y[3] = __cubicInterpolate(stencil + 12, x);
+    buf_cubic_y[3] = _cubicInterpolate(stencil + 12, x);
 
-    return __cubicInterpolate(buf_cubic_y, y);
+    return _cubicInterpolate(buf_cubic_y, y);
 }
 
 void toolsFloat2DMapCopy(double* src, double* dest, int src_xstart, int src_ystart, int dest_xstart, int dest_ystart, int xsize, int ysize, int src_xstep, int src_ystep, int dest_xstep, int dest_ystep)

lib_paysages/tools.h

@@ -11,6 +11,7 @@ extern "C" {
 #define UNUSED(_x_) ((void)(_x_))
 
 double toolsRandom();
+double toolsCubicInterpolate(double stencil[4], double x);
 double toolsBicubicInterpolate(double stencil[16], double x, double y);
 void toolsFloat2DMapCopy(double* src, double* dest, int src_xstart, int src_ystart, int dest_xstart, int dest_ystart, int xsize, int ysize, int src_xstep, int src_ystep, int dest_xstep, int dest_ystep);
 Vector3 toolsGetNormalFromTriangle(Vector3 center, Vector3 bottom, Vector3 right);