Referência do Arquivo /home/carolina/workspace/spvolren_cpu/preint.h

Vá para o código-fonte deste arquivo.

Funções
void	calcPreIntTable (int imgsize, float thickness, unsigned char *data, unsigned char *table)

---

Funções

void calcPreIntTable	(	int	imgsize,
		float	thickness,
		unsigned char *	data,
		unsigned char *	table
	)

Definição na linha 19 do arquivo preint.c.

{
        int sb, sf, i, j, n, base1, base2, offset;
        double stepWidth, s, temp;
        double rgba[4], rgbac[4];

        g.data = data;

        for (sb = 0; sb < imgsize; sb++) {
                for (sf = 0; sf <= sb; sf++) {
                        n = MIN_INT_STEPS + ADD_LOOKUP_STEPS * abs(sb - sf);

                        stepWidth = thickness/n;
                        memset(rgba, 0, sizeof(rgba));

                        for (i = 0; i < n; i++) {
                                s = sf + (sb - sf) * (double)i/n;
                                offset = sf != sb;

#if 0
                                fprintf(stderr, "sb = %i; sf = %i; n = %i; s = %lf\n",
                                                sb, sf, n, s);
#endif

                                rgbac[3] = stepWidth/255.0 * 
                                                   LERP(VAL(s, 3), VAL(s + offset, 3), s - floor(s));
#if 0
                                fprintf(stderr, "%f\n", LERP(VAL(s, 3), VAL(s + 1, 3), s -
                                floor(s))/255.0);
#endif
                                
                                /* Standard optical model: RGB densities are multiplied with
                                 * opacity density */ 
                                temp = exp(-rgba[3]) * rgbac[3]/255.0;
#if 0
                                fprintf(stderr, "%f %f\n", exp(-rgba[3]), rgba[3]);
#endif
                                for (j = 0; j < 3; j++) {
                                        rgbac[j] = temp * 
                                                           LERP(VAL(s, j), VAL(s + offset, j), 
                                                                        s - floor(s));
                                        rgba[j] += rgbac[j];
                                }
                                rgba[3] += rgbac[3];
                        } 
                        
                        base1 = (sb * imgsize + sf) * 4;
                        base2 = (sf * imgsize + sb) * 4;
                        for (i = 0; i < 3; i ++) {
                                if (rgba[i] > 1.0) {
                                        rgba[i] = 1.0;
                                }
                                table[base1++] = table[base2++] = (unsigned char)(rgba[i] * 255.99);
                        }
                        table[base1] = table[base2] = (unsigned char)((1.0 - exp(-rgba[3])) * 255.99);
                }
        }
}