999       #define CASE(a,b)   case COMBO(a,b): for(i=x-1; i >= 0; --i, src += a, dest += b)  in convert_format()  macro
1003          CASE(1,2) dest[0]=src[0], dest[1]=255;  in convert_format()
1005          CASE(1,3) dest[0]=dest[1]=dest[2]=src[0];  in convert_format()
1007          CASE(1,4) dest[0]=dest[1]=dest[2]=src[0], dest[3]=255;  in convert_format()
1009          CASE(2,1) dest[0]=src[0];  in convert_format()
1011          CASE(2,3) dest[0]=dest[1]=dest[2]=src[0];  in convert_format()
1013          CASE(2,4) dest[0]=dest[1]=dest[2]=src[0], dest[3]=src[1];  in convert_format()
1015          CASE(3,4) dest[0]=src[0],dest[1]=src[1],dest[2]=src[2],dest[3]=255;  in convert_format()
1017          CASE(3,1) dest[0]=compute_y(src[0],src[1],src[2]);  in convert_format()
1019          CASE(3,2) dest[0]=compute_y(src[0],src[1],src[2]), dest[1] = 255;  in convert_format()
1021          CASE(4,1) dest[0]=compute_y(src[0],src[1],src[2]);  in convert_format()
1023          CASE(4,2) dest[0]=compute_y(src[0],src[1],src[2]), dest[1] = src[3];  in convert_format()
1025          CASE(4,3) dest[0]=src[0],dest[1]=src[1],dest[2]=src[2];  in convert_format()
1029       #undef CASE  in convert_format()
2750          #define CASE(f) \  in create_png_image_raw()  macro
2755             CASE(F_none)  cur[k] = raw[k];  in create_png_image_raw()
2757             CASE(F_sub)   cur[k] = raw[k] + cur[k-img_n];  in create_png_image_raw()
2759             CASE(F_up)    cur[k] = raw[k] + prior[k];  in create_png_image_raw()
2761             CASE(F_avg)   cur[k] = raw[k] + ((prior[k] + cur[k-img_n])>>1);  in create_png_image_raw()
2763             CASE(F_paeth)  cur[k] = (uint8) (raw[k] + paeth(cur[k-img_n],prior[k],prior[k-img_n]));  in create_png_image_raw()
2765             CASE(F_avg_first)    cur[k] = raw[k] + (cur[k-img_n] >> 1);  in create_png_image_raw()
2767             CASE(F_paeth_first)  cur[k] = (uint8) (raw[k] + paeth(cur[k-img_n],0,0));  in create_png_image_raw()
2770          #undef CASE  in create_png_image_raw()
2773          #define CASE(f) \  in create_png_image_raw()  macro
2778             CASE(F_none)  cur[k] = raw[k];  in create_png_image_raw()
2780             CASE(F_sub)   cur[k] = raw[k] + cur[k-out_n];  in create_png_image_raw()
2782             CASE(F_up)    cur[k] = raw[k] + prior[k];  in create_png_image_raw()
2784             CASE(F_avg)   cur[k] = raw[k] + ((prior[k] + cur[k-out_n])>>1);  in create_png_image_raw()
2786             CASE(F_paeth)  cur[k] = (uint8) (raw[k] + paeth(cur[k-out_n],prior[k],prior[k-out_n]));  in create_png_image_raw()
2788             CASE(F_avg_first)    cur[k] = raw[k] + (cur[k-out_n] >> 1);  in create_png_image_raw()
2790             CASE(F_paeth_first)  cur[k] = (uint8) (raw[k] + paeth(cur[k-out_n],0,0));  in create_png_image_raw()
2793          #undef CASE  in create_png_image_raw()