added velocity color mode

Author: Driema

README.md

@@ -1,6 +1,8 @@
 Euler fluid simulation
 ===
-![Demo Gif](demo/euler-fluid-simulation-resized.gif)
+![Demo Gif](demo/euler-fluid-simulation-default.gif)
+![Demo Gif](demo/euler-fluid-simulation-hsb.gif)
+![Demo Gif](demo/euler-fluid-simulation-velocity.gif)
 
 ## Inspiration
 
@@ -25,7 +27,7 @@ Pressing left mouse will add `density`.
 Dragging the mouse will apply `force` towards the moving direction.
 
 Keyboard options:
- - `c` = Color Mode
+ - `c` = switch color mode (default, hsb, velocity)
 
 ## Building the project
 

demo/euler-fluid-simulation-resized.gif renamed to demo/euler-fluid-simulation-default.gif

@@ -0,0 +1 @@
+enum class Color { Default, Hsb, Velocity };

demo/euler-fluid-simulation-hsb.gif

@@ -3,6 +3,7 @@
 
 #include "./physics.h"
 #include "./const.h"
+#include "./options.h"
 
 class Container {
 private:
@@ -24,6 +25,7 @@ class Container {
 	float density[SIZE*SIZE];
 
 	void InitArr(float arr[], int size);
+	float MapToRange(float value, float minIn, float maxIn, float minOut, float maxOut);
 public:
 	Container();
 	Container(float dt, float diff, float visc);
@@ -32,7 +34,7 @@ class Container {
 	void AddDensity(float x, float y, float amount);
 	void AddVelocity(float x, float y, float px, float py);
 	void Step();
-	void Render(sf::RenderWindow& win, bool color);
+	void Render(sf::RenderWindow& win, Color color);
 	void FadeDensity(int size);
 
 	sf::Color Hsv(int hue, float sat, float val, float d);

demo/euler-fluid-simulation-velocity.gif

@@ -1,10 +1,12 @@
+#include "./color.h"
+
 class Options {
 private:
-	bool color;
+	Color color;
 public:
-	Options(bool color=false);
+	Options(Color color=Color::Default);
 	~Options();
 
-	bool GetColor();
-	void SetColor(bool value);
+	Color GetColor();
+	void SetColor(Color c);
 };

header/color.h

@@ -1,7 +1,6 @@
 #include<vector>
 
 #include "./container.h"
-#include "./options.h"
 
 class Sim {
 private:

header/container.h

@@ -81,19 +81,36 @@ sf::Color Container::Hsv(int hue, float sat, float val, float d) {
   	}
 }
 
-void Container::Render(sf::RenderWindow& win, bool color) {
+float Container::MapToRange(float val, float minIn, float maxIn, float minOut, float maxOut) {
+	float x = (val - minIn) / (maxIn - minIn);
+	float result = minOut + (maxOut - minOut) * x;
+	return (result < minOut) ? minOut : (result > maxOut) ? maxOut : result;
+}
+
+void Container::Render(sf::RenderWindow& win, Color color) {
 	win.clear();
 	for (int i = 0; i < this->size; i++) {
 		for(int j = 0; j < this->size; j++) {
 			sf::RectangleShape rect;
 			rect.setSize(sf::Vector2f(SCALE, SCALE));
 			rect.setPosition(j * SCALE, i * SCALE);
 
-			if (color) {
-				rect.setFillColor(this->Hsv((this->density[IX(i,j,this->size)]), 1, 1, 255));
-			} else {
-				rect.setFillColor(sf::Color(255, 255, 255, this->density[IX(i,j,this->size)]));
-			}
+			switch (color) {
+				case Color::Default:
+					rect.setFillColor(sf::Color(255, 255, 255, this->density[IX(i,j,this->size)]));
+					break;
+				case Color::Hsb:
+					rect.setFillColor(this->Hsv((this->density[IX(i,j,this->size)]), 1, 1, 255));
+					break;
+				case Color::Velocity: {
+						int r = (int)this->MapToRange(this->x[IX(i,j,this->size)], -0.05f, 0.05f, 0, 255);
+						int g = (int)this->MapToRange(this->y[IX(i,j,this->size)], -0.05f, 0.05f, 0, 255);
+						rect.setFillColor(sf::Color(r, g, 255));
+						break;
+					}
+				default:
+					break;
+			};	
 
 			win.draw(rect);
 		}

header/options.h

@@ -1,11 +1,11 @@
 #include "../header/options.h"
 
-Options::Options(bool color) {
+Options::Options(Color color) {
 	this->color = color;
 }
 
 Options::~Options() {}
 
-bool Options::GetColor() { return this->color; }
+Color Options::GetColor() { return this->color; }
 
-void Options::SetColor(bool value) { this->color = value; }
+void Options::SetColor(Color c) { this->color = c; }