Routines
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E300: Paint Message Buffer
Used by the routine at Print_EncodedMessage.
Paint the decoded buffer at PrimaryDisplayBuffer with the double-height font at Font_MessageCharacters, pulsing the attribute through 96 frames.
Point the character set at the message font and paint the buffer until the flash counter hits 96.
Paint_MessageBuffer E300 XOR A Clear A, then clear the message-frame counter (DDA2).
E301 LD ($DDA2),A
E304 LD HL,$E42B Point HL at the message font + 01 (Font_MessageCharacters + 01), then store it as the current character set.
E307 LD ($72F9),HL
Repaint the decoded buffer at PrimaryDisplayBuffer from attribute row 58C0 (attribute buffer).
Paint_MessageBuffer_Frame E30A LD HL,$58C0 Point HL at the message attribute row (58C0 (attribute buffer)).
E30D LD IX,$63A0 Point IX at the decoded message buffer (PrimaryDisplayBuffer).
E311 LD A,($DDA2) Fetch the message-frame counter (DDA2). Has it reached 96 frames? If not, continue the pulse at Paint_MessageBuffer_PulseAttr.
E314 CP $96
E316 JR NZ,Paint_MessageBuffer_PulseAttr
E318 CALL Clear_BothDisplayBuffers Call Clear_BothDisplayBuffers to clear both display buffers.
E31B RET Return.
Pulse the text attribute from the frame counter at DDA2 after dividing by 08, never leaving it at zero.
Paint_MessageBuffer_PulseAttr E31C INC A Advance the frame counter and store it back at DDA2.
E31D LD ($DDA2),A
E320 SRL A Divide A by 08 to slow the attribute pulse.
E322 SRL A
E324 SRL A
E326 OR A Is the pulsed value zero? If not, jump to Paint_MessageBuffer_ClampAttr.
E327 JR NZ,Paint_MessageBuffer_ClampAttr
E329 INC A Force a minimum pulse of 01.
Clamp the pulsed attribute to white (07) when it reaches 08 or above.
Paint_MessageBuffer_ClampAttr E32A CP $08 Is the pulsed attribute < 08? If so, keep it at Paint_MessageBuffer_StoreAttr. Otherwise clamp it to white (07).
E32C JR C,Paint_MessageBuffer_StoreAttr
E32E LD A,$07
Store the pulsed ink in CurrentTextAttribute and its 07−value inverse shift in DDA0.
Paint_MessageBuffer_StoreAttr E330 LD C,A Keep the attribute in C.
E331 LD ($7307),A Store it as the current text attribute (CurrentTextAttribute).
E334 LD A,$07 Compute 07−attribute.
E336 SUB C Subtract the centred column from 07 to get the left pad.
E337 LD ($DDA0),A Store that inverse shift at DDA0 (used while plotting).
Centre and draw one message row via Centre_AndDrawMessageRow, then step three attribute rows for the next.
Paint_MessageBuffer_RowLoop E33A CALL Centre_AndDrawMessageRow Call Centre_AndDrawMessageRow to centre and draw one message row.
E33D LD A,($DDA1) Fetch the row-terminator byte saved by Centre_AndDrawMessageRow (DDA1). Was it the message end (])? If so, restart a new frame at Paint_MessageBuffer_Frame.
E340 CP $5D
E342 JR Z,Paint_MessageBuffer_Frame
E344 LD BC,$0060 Step HL down by 0060 attribute bytes (three rows).
E347 ADD HL,BC Advance HL by one message row (0060 attribute bytes).
E348 JR Paint_MessageBuffer_RowLoop Draw the next message row at Paint_MessageBuffer_RowLoop.
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