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> It would be easier to just use the command-line parameter:
There's often easier ways... like looking at the image size
in an editor.
A built-in function for this would be handy...
The file_image_size macro tries to measure the pixel width
by sampling at random for a point that differs in color from
it's neighbors. Not all images have such points, so this
can fail to report the proper sizes on low-color images.
#include "strings.inc"
#include "math.inc"
// internal macro for file_image_size
#macro seek(point, dist)
#local rez = dist*0.1;
#local RP_COLOR = _IMF(point.x, point.y, point.z);
#local seekcount = 0;
#local seekf = true;
#local last = point;
#while (seekf & (seekcount<11))
#local seekcount = seekcount + 1;
#local samp = point+seekcount*rez;
#local TEMP_COLOR = _IMF(samp.x,samp.y,samp.z);
#local seekf = VEq5D(RP_COLOR, TEMP_COLOR);
#if (seekf) #local last = samp; #end
#end
#local zed = 0.00001; // desired accuracy
#if ((abs(rez.x)>zed)|(abs(rez.y)>zed)|(abs(rez.z)>zed))
#local result = seek(last, rez);
#else
#local result = samp;
#end
(result)
#end
// returns a 2D vector with the image size
// Usage: (string, string, float)
// itype = the image type
// iname = the file name
// num = the number of samples
// Example: #local G1 = file_image_size("png", "plasma3.png", 12);
#macro file_image_size(itype, iname, num)
#local SI = "#declare _IMF = function {\n";
#local SI = concat(SI, "pigment {\n");
#local SI = concat(SI, "image_map {\n");
#local SI = concat(SI, itype," \"",iname,"\"\n");
#local SI = concat(SI, "map_type 0\n");
#local SI = concat(SI, "once}scale 1000000}};\n");
Parse_String(SI)
#local S = seed(num);
#local DX = 1000000;
#local DY = 1000000;
#local C = 0;
#while (C < num)
// a random point
#local RP = <rand(S)*1000000,rand(S)*1000000,0>;
#local temp = seek(RP, <DX,0,0>);
#local xright = temp.x;
#local temp = seek(RP, <-DX,0,0>);
#local xleft = temp.x;
#local temp = seek(RP, <0,DY,0>);
#local yup = temp.y;
#local temp = seek(RP, <0,-DY,0>);
#local ydown = temp.y;
// found
#local found_DX = (xright-xleft);
#local found_DY = (yup-ydown);
// adjust pixel size guess
#local DX = min(DX,found_DX);
#local DY = min(DY,found_DY);
#local C = C + 1;
#end
#undef _IMF
#local result = <int((1/DX)*1000000+0.9999), int((1/DY)*1000000+0.9999)>;
(result)
#end
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com> wrote: