Files
Examples/C++/Doom Fire Algorithm/main.cpp
2019-02-02 20:53:16 +00:00

108 lines
3.9 KiB
C++

#include <iostream>
#include <cstdlib>
#define OLC_PGE_APPLICATION
#include "olcPixelGameEngine.h"
int WINDOW_HEIGHT = 720 / 4;
int WINDOW_WIDTH = 1280 / 4;
int* firePixelsArray = new int[(WINDOW_WIDTH) * (WINDOW_HEIGHT)];
int numberOfPixels = (WINDOW_WIDTH) * (WINDOW_HEIGHT);
int fireColoursPalette[37][3] = {{7, 7, 7}, {31, 7, 7}, {47, 15, 7}, {71, 15, 7}, {87, 23, 7}, {103, 31, 7}, {119, 31, 7}, {143, 39, 7}, {159, 47, 7}, {175, 63, 7}, {191, 71, 7}, {199, 71, 7}, {223, 79, 7}, {223, 87, 7}, {223, 87, 7}, {215, 95, 7}, {215, 95, 7}, {215, 103, 15}, {207, 111, 15}, {207, 119, 15}, {207, 127, 15}, {207, 135, 23}, {199, 135, 23}, {199, 143, 23}, {199, 151, 31}, {191, 159, 31}, {191, 159, 31}, {191, 167, 39}, {191, 167, 39}, {191, 175, 47}, {183, 175, 47}, {183, 183, 47}, {183, 183, 55}, {207, 207, 111}, {223, 223, 159}, {239, 239, 199}, {255, 255, 255}};
class FireSim : public olc::PixelGameEngine {
public:
FireSim() {
sAppName = "Doom Fire Simulator";
}
bool OnUserCreate() override {
for (int i = 0; i < numberOfPixels; i++) {
firePixelsArray[i] = 36;
}
return true;
};
bool OnUserUpdate(float fElapsedTime) override {
m_timeAccumilator += fElapsedTime;
if (m_timeAccumilator >= 0.033) {
m_timeAccumilator = 0.0f;
#pragma omp parallel for schedule(dynamic)
for (int i = 0; i < numberOfPixels; i++) {
UpdateFireIntensity(i);
}
}
Render();
if (GetMouse(0).bHeld) {
Vec2<int> m = {GetMouseX(), GetMouseY()};
auto fillCircle = [&](int x, int y, int radius, int val) {
// Taken from wikipedia
int x0 = 0;
int y0 = radius;
int d = 3 - 2 * radius;
if (!radius) return;
auto drawline = [&](int sx, int ex, int ny) {
for (int i = sx; i <= ex; i++)
firePixelsArray[ny * WINDOW_WIDTH + i] = val;
};
while (y0 >= x0) {
// Modified to draw scan-lines instead of edges
drawline(x - x0, x + x0, y - y0);
drawline(x - y0, x + y0, y - x0);
drawline(x - x0, x + x0, y + y0);
drawline(x - y0, x + y0, y + x0);
if (d < 0) d += 4 * x0++ + 6;
else d += 4 * (x0++ - y0--) + 10;
}
};
fillCircle(m.x, m.y, 4, 36);
}
return true;
}
void UpdateFireIntensity(int pixel) {
int pixelBelowIndex = pixel + WINDOW_WIDTH;
if (pixelBelowIndex < numberOfPixels) {
int decay = floor(rand() % 3);
int pixelBelowIntensity = firePixelsArray[pixelBelowIndex];
int intensity = pixelBelowIntensity - decay >= 0 ? pixelBelowIntensity - decay : 0;
int position = (pixel - decay >= 0) ? pixel - decay : 0;
firePixelsArray[position] = intensity;
}
}
void Render() {
Clear(olc::BLACK);
for (int x = 0; x < WINDOW_WIDTH; x++) {
for (int y = 0; y < WINDOW_HEIGHT; y++) {
int pixel = x + (WINDOW_WIDTH * y);
int fireIntensity = firePixelsArray[pixel];
uint8_t r = fireColoursPalette[fireIntensity][0];
uint8_t g = fireColoursPalette[fireIntensity][1];
uint8_t b = fireColoursPalette[fireIntensity][2];
olc::Pixel col = {r, g, b, 255};
FillRect(x, y, 1, 1, col);
}
}
}
bool OnUserDestroy() override {
delete[] firePixelsArray;
return true;
}
private:
float m_timeAccumilator = 0.0f;
};
int main(int argc, char** argv) {
FireSim app;
if (app.Construct(WINDOW_WIDTH, WINDOW_HEIGHT, 4, 4))
app.Start();
return 0;
}