Data commit

Task/Bitmap-Read-a-PPM-file/BBC-BASIC/bitmap-read-a-ppm-file.basic

@@ -0,0 +1,30 @@
+      f% = OPENIN("c:\lena.ppm")
+      IF f%=0 ERROR 100, "Failed to open input file"
+
+      IF GET$#f% <> "P6" ERROR 101, "File is not in P6 format"
+      REPEAT
+        in$ = GET$#f%
+      UNTIL LEFT$(in$,1) <> "#"
+      size$ = in$
+      max$ = GET$#f%
+
+      Width% = VAL(size$)
+      space% = INSTR(size$, " ")
+      Height% = VALMID$(size$, space%)
+
+      VDU 23,22,Width%;Height%;8,16,16,128
+
+      FOR y% = Height%-1 TO 0 STEP -1
+        FOR x% = 0 TO Width%-1
+          r% = BGET#f% : g% = BGET#f% : b% = BGET#f%
+          l% = INT(0.3*r% + 0.59*g% + 0.11*b% + 0.5)
+          PROCsetpixel(x%,y%,l%,l%,l%)
+        NEXT
+      NEXT y%
+      END
+
+      DEF PROCsetpixel(x%,y%,r%,g%,b%)
+      COLOUR 1,r%,g%,b%
+      GCOL 1
+      LINE x%*2,y%*2,x%*2,y%*2
+      ENDPROC