COMMENT ⊗   VALID 00003 PAGES
C REC  PAGE   DESCRIPTION
C00001 00001
C00002 00002	BEGIN "TMP"
C00004 00003	α FIELD OF VIEW ANGLES
C00006 ENDMK
C⊗;
BEGIN "TMP"
	REQUIRE "ABBREV[SYS,BGB]" SOURCE_FILE;
	REQUIRE "SAITRG[SYS,BGB]" SOURCE_FILE;
	REQUIRE "DPYIII[SYS,BGB]" SOURCE_FILE;
	SAFE ITG ARRAY DPYBUF[0:500];
	SAFE REAL ARRAY CAMBUF[0:9];

	REAL FOCAL,PDX,PDY;
	REAL FANGX,FANGY;	α FIELD OF VIEW ANGLES;

	DEFINE FEET="3.280833";		α PER METER;
	DEFINE METERS=".3048006";	α PER FOOT;
	DEFINE MM="304.8006";		α PER FOOT;
	DEFINE MICRONS="304800.6";	α PER FOOT;

α GET A TYPICAL CAMERA FILE;
	OPEN(1,"DSK",8,3,0,0,0,0);
	LOOKUP(1,"CAMERA.CAM",0);
	ARRYIN(1,CAMBUF[0],10);RELEASE(1);

	PDX ← CAMBUF[6];
	PDY ← CAMBUF[7];
	FOCAL ← CAMBUF[9] * 2;

	OUTSTR(9&"PDX = "&CVG(PDX*10↑6)&" MICRONS."&↓);
	OUTSTR(9&"PDY = "&CVG(PDY*10↑6)&" MICRONS."&↓);
	OUTSTR(9&"FOCAL = "&CVG(FOCAL*10↑3)&" MILLIMETERS."&↓&↓);

α FIELD OF VIEW ANGLES;
	FANGX ← 2*ATAN2(144*PDX,FOCAL);
	FANGY ← 2*ATAN2(108*PDY,FOCAL);

	OUTSTR(9&"FANGX = "&CVG(FANGX*180/π)&" DEGREES."&↓);
	OUTSTR(9&"FANGY = "&CVG(FANGY*180/π)&" DEGREES."&↓);
	OUTSTR(9&"PER CENT SPHERE OF VIEW = "&CVG(25*FANGX*FANGY/π)&↓);

α DISPLAY PLANE-MAP OF FIELD OF VIEW;
	
	DPYSET(DPYBUF);

	AIVECT(-400,-400);AVECT(400,-400);
	AIVECT(0,-500);AVECT(0,+400);

	AIVECT(0,-400);AVECT(800*144*PDX/FOCAL,400);
	AVECT(-800*144*PDX/FOCAL,400);AVECT(0,-400);

	DPYOUT(1);

	WHILE TRUE DO INCHRW;
END;