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#ifndef PatternStarfield_H
#define PatternStarfield_H
struct Star
{
Star() {
x = y = z = 0;
colour = CRGB::White;
}
float x;
float y;
float z;
CRGB colour;
};
// Based on https://github.com/sinoia/oled-starfield/blob/master/src/starfield.cpp
class PatternStarfield : public Drawable {
private:
const int starCount = 100; // number of stars in the star field
const int maxDepth = 32; // maximum distance away for a star
// the star field - starCount stars represented as x, y and z co-ordinates
// https://www.cplusplus.com/doc/tutorial/dynamic/
Star * stars;
//CRGBPalette16 currentPalette;
unsigned int drawFrame() { // aka drawStars
// Dim routine
for (int16_t i = 0; i < VPANEL_W; i++) {
for (int16_t j = 0; j < VPANEL_H; j++) {
uint16_t xy = XY16(i, j);
effects.leds[xy].nscale8(250);
}
}
int origin_x = VPANEL_W / 2;
int origin_y = VPANEL_H / 2;
// Iterate through the stars reducing the z co-ordinate in order to move the
// star closer.
for (int i = 0; i < starCount; ++i) {
stars[i].z -= 0.1;
// if the star has moved past the screen (z < 0) reposition it far away
// with random x and y positions.
if (stars[i].z <= 0)
{
stars[i].x = getRandom(-25, 25);
stars[i].y = getRandom(-25, 25);
stars[i].z = maxDepth;
}
// Convert the 3D coordinates to 2D using perspective projection.
float k = VPANEL_W / stars[i].z;
int x = static_cast<int>(stars[i].x * k + origin_x);
int y = static_cast<int>(stars[i].y * k + origin_y);
// Draw the star (if it is visible in the screen).
// Distant stars are smaller than closer stars.
if ((0 <= x and x < VPANEL_H)
and (0 <= y and y < VPANEL_H)) {
CRGB tmp = stars[i].colour;
//CRGB tmp = CRGB::White;
byte scale = 255 -(stars[i].z*7);
tmp.nscale8(scale);
effects.setPixel(x,y, CRGB(tmp.r,tmp.g,tmp.b));
}
else
{
stars[i].z = -1; // set to -1 so it gets re-popualted
}
}
effects.ShowFrame();
return 5;
}
int getRandom(int lower, int upper) {
/* Generate and return a random number between lower and upper bound */
return lower + static_cast<int>(rand() % (upper - lower + 1));
}
/*
CRGB ColorFromCurrentPalette(uint8_t index = 0, uint8_t brightness = 255, TBlendType blendType = LINEARBLEND) {
return ColorFromPalette(currentPalette, index, brightness, blendType);
}
*/
public:
PatternStarfield()
{
name = (char *)"PatternStarfield";
}
void start() {
//currentPalette = RainbowColors_p;
//currentPalette = CloudColors_p;
// Allocate memory
stars = new Star[starCount];
// Initialise the star field with random stars
for (int i = 0; i < starCount; i++) {
stars[i].x = getRandom(-25, 25);
stars[i].y = getRandom(-25, 25);
stars[i].z = getRandom(0, maxDepth);
//stars[i].colour = ColorFromCurrentPalette(random(0, 128));
stars[i].colour = effects.ColorFromCurrentPalette(random(0, 128));
}
} // end start
void stop() {
delete[] stars;
}
};
#endif
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