Tweaks, trying to get it to work

perlin/perlin_noise.cpp

@@ -30,26 +30,21 @@
 //-------------------------
 
 double SimpleRNG::operator()(double x) {
-	x = x * seed * 345589144.0 + 1123581321.0;
-	return fmod(x, 21795.0);
+	return (x + seed) * 345589144.0 + 1123581321.0;
 };
 
 Vector2 PerlinNoise::Gradient(Vector2 pos) {
 	//could cache this result
-	double j = rng(pos.y*pos.y + pos.x * 144);
-	double i = rng(pos.x*pos.x + pos.y * 144);
-	Vector2 v(i, j);
+	double angle = rng(pos.x * pos.y + pos.y);
+	Vector2 v(cos(angle), sin(angle));
 	v.Normalize();
 	return v;
 }
 
-double PerlinNoise::Influcence(Vector2 gridPoint, Vector2 queryPoint) {
-	return ScalarProduct(Gradient(gridPoint), queryPoint - gridPoint);
-}
-
 double PerlinNoise::Noise(double x, double y, double width, double height) {
-	Vector2 point = {x, y};
+	Vector2 queryPoint = {x, y};
 
+	//calc the region's position
 	x = Snap(x, width);
 	y = Snap(y, height);
 
@@ -60,10 +55,10 @@ double PerlinNoise::Noise(double x, double y, double width, double height) {
 	Vector2 br = {x + width, y + height};
 
 	//influence equasion
-	double s = Influcence(tl, point);
-	double t = Influcence(tr, point);
-	double u = Influcence(bl, point);
-	double v = Influcence(br, point);
+	double s = ScalarProduct(Gradient(tl), queryPoint - tl);
+	double t = ScalarProduct(Gradient(tr), queryPoint - tr);
+	double u = ScalarProduct(Gradient(bl), queryPoint - bl);
+	double v = ScalarProduct(Gradient(br), queryPoint - br);
 
 	//get the noise
 	double a = s + Curve((t - s) / width);

src/shell_scene.cpp

@@ -21,6 +21,8 @@
 */
 #include "shell_scene.hpp"
 
+#include <iostream>
+
 //-------------------------
 //Public access members
 //-------------------------
@@ -31,19 +33,21 @@ void setPixel(SDL_Surface* const dest, int x, int y, int colour) {
 
 ShellScene::ShellScene() {
 	//test the generator
-	int width = 800;
-	int height = 600;
-	image.CreateSurface(width, height);
-
-	int white = SDL_MapRGB(image.GetSurface()->format, 255, 255, 255);
+	int width = 80;
+	int height = 80;
+	image.CreateSurface(GetScreen()->w, GetScreen()->h);
 
 	double mod;
-	for (int i = 0; i < width; i++) {
-		for (int j = 0; j < height; j++) {
+	int colour;
+	std::cout << "Beggining generation" << std::endl;
+	for (int i = 0; i < image.GetSurface()->w; i++) {
+		for (int j = 0; j < image.GetSurface()->h; j++) {
 			mod = generator.Noise(i, j, width, height);
-			setPixel(image.GetSurface(), i, j, white*mod);
+			colour = SDL_MapRGB(image.GetSurface()->format, 255*mod, 255*mod, 255*mod);
+			setPixel(image.GetSurface(), i, j, colour);
 		}
 	}
+	std::cout << "Finished generation" << std::endl;
 }
 
 ShellScene::~ShellScene() {