Prev: 27109 Up: Map Next: 27143
27110: Place a font character bitmap into a message graphic buffer
Used by the routines at 27419 and 27144. Appends a font character bitmap (corresponding to the ASCII code in A) to the existing contents of a message graphic buffer.
A ASCII code
C Pixel columns remaining in the buffer
HL' Buffer address
27110 LD E,A E=ASCII code (32-127)
27111 LD D,215 Point DE at the appropriate entry in the table of font character bitmap widths at 55072
27113 LD A,(DE) A=width of the font character in pixels (1-5)
27114 LD B,A Store this in B
27115 INC D
27116 LD A,(DE) A=bit pattern for one pixel column of the font character
27117 CALL 27125 Slide this into the message buffer
27120 DEC C One fewer pixel column remaining in the message buffer
27121 DJNZ 27115 Jump back until all pixel columns for the font character have been copied into the message buffer
27123 DEC C One fewer pixel column remaining in the message buffer
This entry point is used by the routine at 27419.
27124 XOR A A=0 (blank pixel column)
27125 EXX
27126 PUSH HL
27127 LD C,8 8 pixels per column
27129 LD B,32 32 (during startup) or 8 bytes per pixel row (this instruction is set to LD B,8 before the game starts; see 21408)
27131 RRCA Push a pixel into the carry flag
27132 RL (HL) Drag the pixel into the message buffer and shove the existing pixels one place to the left
27134 DEC HL
27135 DJNZ 27132
27137 DEC C
27138 JR NZ,27129 Jump back to collect the next pixel up
27140 POP HL Restore the address of the last byte in the message buffer to HL'
27141 EXX
27142 RET
Prev: 27109 Up: Map Next: 27143