From 02a026116da22aba5e7715ad823769f9d33955c5 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Micha=C3=ABl=20Lemaire?= <michael@thunderk.net>
Date: Mon, 4 Jan 2016 20:26:40 +0100
Subject: [PATCH] Fixed noise scaling in opengl

---
 src/basics/NoiseFunctionSimplex.cpp  | 31 ++++++++++++++++++----------
 src/interface/commandline/tests.cpp  | 30 ++++++++++++++++++++-------
 src/render/opengl/shaders/noise.frag |  4 ++--
 3 files changed, 45 insertions(+), 20 deletions(-)

diff --git a/src/basics/NoiseFunctionSimplex.cpp b/src/basics/NoiseFunctionSimplex.cpp
index a38a21a..fc8b4dc 100644
--- a/src/basics/NoiseFunctionSimplex.cpp
+++ b/src/basics/NoiseFunctionSimplex.cpp
@@ -476,18 +476,22 @@ double NoiseFunctionSimplex::getBase3d(double x, double y, double z) const {
     return noiseSimplexGet3DValue(x, y, z) - 0.5;
 }
 
+static constexpr double TEXTURE_SCALING = 15.0;
 static Texture2D *_valueTexture = NULL;
 
 const Texture2D *NoiseFunctionSimplex::getValueTexture() {
     if (!_valueTexture) {
-        const int width = 1024;
-        const int height = 1024;
+        const int width = 2048;
+        const int height = 2048;
 
         _valueTexture = new Texture2D(width, height);
 
         for (int x = 0; x < width; x++) {
             for (int z = 0; z < height; z++) {
-                double val = noiseSimplexGet2DValue(to_double(x), to_double(z)) - 0.5;
+                // TODO Make texture tileable
+                double dx = to_double(x) / to_double(width);
+                double dz = to_double(z) / to_double(height);
+                double val = noiseSimplexGet2DValue(TEXTURE_SCALING * dx, TEXTURE_SCALING * dz);
                 _valueTexture->setPixel(x, z, Color(val, val, val));
             }
         }
@@ -500,22 +504,27 @@ static Texture2D *_normalTexture = NULL;
 
 const Texture2D *NoiseFunctionSimplex::getNormalTexture() {
     if (!_normalTexture) {
-        const int width = 1024;
-        const int height = 1024;
+        const int width = 2048;
+        const int height = 2048;
 
         _normalTexture = new Texture2D(width, height);
 
+        double scale = TEXTURE_SCALING;
+        double offset = scale * 0.1;
+
         for (int x = 0; x < width; x++) {
             for (int z = 0; z < height; z++) {
                 // TODO Make texture tileable
-                double vcenter = noiseSimplexGet2DValue(0.01 * to_double(x), 0.01 * to_double(z)) - 0.5;
-                double vsouth = noiseSimplexGet2DValue(0.01 * to_double(x), 0.01 * to_double(z) + 0.001) - 0.5;
-                double veast = noiseSimplexGet2DValue(0.01 * to_double(x) + 0.001, 0.01 * to_double(z)) - 0.5;
+                double dx = to_double(x) / to_double(width);
+                double dz = to_double(z) / to_double(height);
+                double vcenter = noiseSimplexGet2DValue(scale * dx, scale * dz) - 0.5;
+                double vsouth = noiseSimplexGet2DValue(scale * dx, scale * dz + offset) - 0.5;
+                double veast = noiseSimplexGet2DValue(scale * dx + offset, scale * dz) - 0.5;
 
-                Vector3 normal = Geometry::getNormalFromTriangle(Vector3(0.0, vcenter, 0.0), Vector3(0.0, vsouth, 0.01),
-                                                                 Vector3(0.01, veast, 0.0));
+                Vector3 normal = Geometry::getNormalFromTriangle(
+                    Vector3(0.0, vcenter, 0.0), Vector3(0.0, vsouth, offset), Vector3(offset, veast, 0.0));
 
-                _normalTexture->setPixel(x, z, Color(normal.x, normal.y, normal.z));
+                _normalTexture->setPixel(x, z, Color(normal.x + 0.5, normal.y + 0.5, normal.z + 0.5));
             }
         }
     }
diff --git a/src/interface/commandline/tests.cpp b/src/interface/commandline/tests.cpp
index ca81b98..b8bdee6 100644
--- a/src/interface/commandline/tests.cpp
+++ b/src/interface/commandline/tests.cpp
@@ -27,7 +27,10 @@
 #include "RayCastingResult.h"
 #include "OpenGLVegetationImpostor.h"
 #include "Texture2D.h"
+#include "NoiseNode.h"
+#include "FractalNoise.h"
 #include "RandomGenerator.h"
+#include "NoiseFunctionSimplex.h"
 
 #include <sstream>
 #include <iostream>
@@ -53,6 +56,18 @@ static void startTestRender(SoftwareCanvasRenderer *renderer, const string &name
     startRender(renderer, getFileName(name, iteration).data());
 }
 
+static void testNoise() {
+    NoiseFunctionSimplex noise;
+
+    string filename = getFileName("noise_simplex_cache_value");
+    cout << "Rendering " << filename << "..." << endl;
+    noise.getValueTexture()->saveToFile(filename);
+
+    filename = getFileName("noise_simplex_cache_normal");
+    cout << "Rendering " << filename << "..." << endl;
+    noise.getNormalTexture()->saveToFile(filename);
+}
+
 static void testGroundShadowQuality() {
     Scenery scenery;
     RandomGenerator random(5);
@@ -345,13 +360,14 @@ static void testOpenGLVegetationImpostor() {
 }
 
 void runTestSuite() {
-    testGroundShadowQuality();
-    testRasterizationQuality();
-    testCloudQuality();
-    testGodRays();
-    testNearFrustum();
-    testCloudsNearGround();
     testAtmosphereBruneton();
-    testVegetationModels();
+    testCloudQuality();
+    testCloudsNearGround();
+    testGodRays();
+    testGroundShadowQuality();
+    testNearFrustum();
+    testNoise();
     testOpenGLVegetationImpostor();
+    testRasterizationQuality();
+    testVegetationModels();
 }
diff --git a/src/render/opengl/shaders/noise.frag b/src/render/opengl/shaders/noise.frag
index af0bd99..d466fc6 100644
--- a/src/render/opengl/shaders/noise.frag
+++ b/src/render/opengl/shaders/noise.frag
@@ -10,8 +10,8 @@ vec3 noiseNormal2d(float[4] data, vec2 location, float detail)
     while (height > detail)
     {
         // TODO offsets
-        // TODO parametrized texture scaling (0.01)
-        normal += texture(simplexSampler, location * 0.01 * scaling).xyz;
+        // TODO parametrized texture scaling
+        normal += texture(simplexSampler, location * scaling / 15.0).xyz - vec3(0.5);
         scaling *= step_scaling;
         height *= step_height;
     }