Oolite Bulletins

Code: Select all

float lerp5( float v0, float v1, float v2, float v3, float v4, float q)
{
	if (q < 0.25)
		return v0 * (1.0 - q * 4.0) + v1 * q * 4.0;
	q -= 0.25;
	if (q < 0.25)
		return v1 * (1.0 - q * 4.0) + v2 * q * 4.0;
	q -= 0.25;
	if (q < 0.25)
		return v2 * (1.0 - q * 4.0) + v3 * q * 4.0;
	q -= 0.25;
	if (q < 0.25)
		return v3 * (1.0 - q * 4.0) + v4 * q * 4.0;
	return v4;	// values of q over 1.0
}

float my_lerp( float v0, float v1, float q)
{
	float q1 = 0.5 * (1.0 + cosf((q + 1.0) * PI));
	return v0 * (1.0 - q1) + v1 * q1;
}

void addNoise(float * buffer, int p, int n, float scale)
{
	int x, y;
	float R[n*n];
	
	for (y = 0; y < n; y++) for (x = 0; x < n; x++) R[y * n + x] = randf();	// random array

	float r = (float)p / (float)n;
	for (y = 0; y < p; y++) for (x = 0; x < p; x++)
	{
		int ix = floor( (float)x / r);
		int jx = (ix + 1) % n;
		int iy = floor( (float)y / r);
		int jy = (iy + 1) % n;
		float qx = x / r - ix;
		float qy = y / r - iy;
		float rix = my_lerp( R[iy * n + ix], R[iy * n + jx], qx);
		float rjx = my_lerp( R[jy * n + ix], R[jy * n + jx], qx);
		float rfinal = scale * my_lerp( rix, rjx, qy);

		buffer[ y * p + x ] += rfinal;
	}
}

void fillSquareImageDataWithSmoothNoise(unsigned char * imageBuffer, int width, int nplanes)
{
	float accbuffer[width * width];
	int x, y;
	for (y = 0; y < width; y++) for (x = 0; x < width; x++) accbuffer[ y * width + x] = 0.0f;

	// generate 6 octaves of noise
	int octave = 4;
	float scale = 0.5;
	int  n;
	for (n = 0; n < 6; n++)
	{
		addNoise( accbuffer, width, octave, scale);
		octave *= 2;
		scale *= 0.5;
	}
	
	for (y = 0; y < width; y++) for (x = 0; x < width; x++)
	{
		int p;
		float q = accbuffer[ y * width + x];
		q = 2.0f * ( q - 0.5f);
		if (q < 0.0f)
			q = 0.0f;
		for (p = 0; p < nplanes - 1; p++)
			imageBuffer[ p + nplanes * (y * width + x) ] = 255 * q;
		imageBuffer[ p + nplanes * (y * width + x) ] = 255;
	}
}

void fillSquareImageWithGenTex(unsigned char * imageBuffer, int width, int nplanes, float impress, float bias,
	OOColor* c0, OOColor* c1, OOColor* c2, OOColor* c3, OOColor* c4)
{
	float accbuffer[width * width];
	int x, y;
	for (y = 0; y < width; y++) for (x = 0; x < width; x++) accbuffer[ y * width + x] = 0.0f;

	// generate 4 octaves of noise
	int octave = 4;
	float scale = 0.5;
	int  n;
	for (n = 0; n < 6; n++)
	{
		addNoise( accbuffer, width, octave, scale);
		octave *= 2;
		scale *= 0.5;
	}
	
	for (y = 0; y < width; y++) for (x = 0; x < width; x++)
	{
		float q = accbuffer[ y * width + x];
		
		q = impress * q + bias;
		
		if (q < 0.0)	q = 0.0;
		if (q > 1.0)	q = 1.0;
		
		float red = lerp5( [c0 redComponent], [c1 redComponent], [c2 redComponent], [c3 redComponent], [c4 redComponent], q);
		float blue = lerp5( [c0 blueComponent], [c1 blueComponent], [c2 blueComponent], [c3 blueComponent], [c4 blueComponent], q);
		float green = lerp5( [c0 greenComponent], [c1 greenComponent], [c2 greenComponent], [c3 greenComponent], [c4 greenComponent], q);
		
		if (nplanes == 1)
			imageBuffer[ y * width + x ] = 255 * q;
		if (nplanes == 3)
		{
			imageBuffer[ 0 + 3 * (y * width + x) ] = 255 * red;
			imageBuffer[ 1 + 3 * (y * width + x) ] = 255 * green;
			imageBuffer[ 2 + 3 * (y * width + x) ] = 255 * blue;
		}
		if (nplanes == 4)
		{
			imageBuffer[ 0 + 4 * (y * width + x) ] = 255 * red;
			imageBuffer[ 1 + 4 * (y * width + x) ] = 255 * green;
			imageBuffer[ 2 + 4 * (y * width + x) ] = 255 * blue;
			imageBuffer[ 3 + 4 * (y * width + x) ] = 255;
		}
	}
}