// *********************************************************************************************************************************************** // *********************************************************************************************************************************************** // // BOMBER : Implementation of classic down the screen game for MB Microvision // // Written by Paul Robson January 2014. // *********************************************************************************************************************************************** // *********************************************************************************************************************************************** // // Bank 0 : System Code Memory // // Bank 1 : Height of the buildings (0-7) x 16 columns, actual physical height // // Bank 2 : 0 Y position of Plane // 1 X position of Plane // 2 Plane speed // 3 Plane speed counter // // 4 Y position of Bomb ($F = don't draw) // 5 X position of Bomb // 6 Bomb Speed // 7 Bomb Speed Counter // // 8 Skill Level. // 9 Column being rendered. // 10 Temporary value // 11 Win-Lose Flag // // 12-15 Column Data (12 = top column) creating graphic for each row. // // Bank 3 : 0-11 Tune space. // 12-15 Bit Patterns for 0,1,2,3 heights. // // Bank 4-7 : 0-6 Score, Score Graphics. // (1 point for each block dropped) // include system.asm // Include System Library // *********************************************************************************************************************************************** // // New Game : Reset Level and Score, Create Lookup Table // // *********************************************************************************************************************************************** ResetGame ldx 2 // Set the level to 1 tcy 8 tcmiy 1 ldx 3 tcy 12 // Set up the height bars for each column tcmiy 0 // Bits are upside down remember :) tcmiy 8 tcmiy 12 tcmiy 14 lcall OSClearDisplaySpace // Clear the display space, which resets the score. // *********************************************************************************************************************************************** // // New Game Level // // *********************************************************************************************************************************************** NextLevel ldx 2 // Update the current level. tcy 8 imac tam tcy 0 // Set X and Y position to zero tcmiy 0 tcmiy 0 tam // Store plane speed in offsest 2 tcy 4 // Set Bomb X and Y position to zero,15 meaning don't draw yet tcmiy 15 tcmiy 15 tcmiy 10 // Default speed to 10 tcy HWKeyMiddleCol // Set the middle key column line, only use one key 'bomb' setr tcy 15 // Generate the bar heights. ResetGameSpace lcall OSRandomNumber // Random number 0-15 ldx 1 // Bank 1 holds the bar heights tam // Store in memory rbit 3 // Make the number 0-7 dman // Load and Decrement. S will be clear if was zero br RGSNotZero // A will be 15,0-6, skip if S set e.g. not 15 cla // A to zero if 15, gives us 0,0,1,2,3,4,5,6 as heights RGSNotZero tamdyn // Write back decrement Y br ResetGameSpace // Do for all of 16 columns. // *********************************************************************************************************************************************** // // Main Game Screen Rendering Loop // // *********************************************************************************************************************************************** MainRenderLoop lcall OSSwitchPolarity ldx 2 // Reset the current column being rendered to zero. tcy 9 tcmiy 0 lbr RenderColumn page RenderColumn ldx 2 // Point to the data row tcy 12 // Clear the column buffer tcmiy 0 tcmiy 0 tcmiy 0 tcmiy 0 tcy 9 // Point to the current column tmy // Read the current column ldx 1 // Read the height of the current column. tma // into A a12aac // Will set S if > 4 call SetLowerColumn // Only set if > 4 call set lower column tay ldx 3 tma // Read the bit pattern into A. ldx 2 // Point to the bottom byte of the column tcy 15 mnez // If non-zero, need to use 14 not 15 as there's a bar below call DecrementY tam // Store the bit pattern in the lower entry. ldx 2 // Draw pixel at (2,0) (e.g. the bomber) tcy 0 lcall DrawPixelAlways ldx 2 // Draw pixel at (2,4) (e.g. the bomb) tcy 4 lcall DrawPixel ldx 2 // Now start to output the 4 bits of data tcy 12 OutputColumnPixels tma // Read it tdo // Send to LCD out tya // Save Y in A tcy HWNotDataClock // Pulse ! DataClock rstr setr tay // Restore Y iyc // Bump it ynec 0 // If not zero then haven't finished br OutputColumnPixels // Output the column pixels. tcy 9 // XY now points to M(2,9) which is the column number tmy // Read it ldx 0 // Use Page 0 for write bits (not mandatory) lcall OSWriteBitsY // Output the column data lcall OSUpdateDisplay // Update the latches. ldx 2 // Point to column number and increment tcy 9 imac // Bump it tam ldp RenderColumn // Loop round to render next column if nonzero mnez br RenderColumn lbr CheckMoving DecrementY dyn retn SetLowerColumn ldx 2 // Solid block in bottom column tcy 15 tcmiy 15 a12aac // Unpicks the a4aac following the call so it's 0-3 retn page // *********************************************************************************************************************************************** // // (2,Y) points to a (Y,X) pixel position. Draw to buffer at (2,12-15). Do not draw if Y = $0F // // *********************************************************************************************************************************************** DrawPixelAlways tya tcy 10 tam tay br _DPMain DrawPixel tya // Y->A tcy 10 // Save Y in (2,10) tam tay // Fix Y back up to point to the Y coordinate. imac // Load the current Y into A and increment, will cause S if 15 (don't draw) br DPExit // If not drawing then exit. _DPMain iyc // Point to X (column position) tma // Load column position into A tcy 9 // Point M(X,Y) to (2,9), the actual column position. mnea // If they are different. br DPExit // Exit without drawing. tcy 10 // Reread Y from (2,10) into Y tmy tma // Read vertical position into A tcy 11 // Where it goes to (1,11) onwards DPFindNibble iyc a12aac // Will cause S *if* >= 4 0-3 will return 12,13,14,15 for A 0-3 br DPFindNibble iac // Set appropriate bit depending on A br DPSet3 iac br DPSet2 iac br DPSet1 sbit 0 retn DPSet3 sbit 3 retn DPSet2 sbit 2 retn DPSet1 sbit 1 DPExit retn // *********************************************************************************************************************************************** // // (2,Y) points to a speed/counter pairing. Returns Y != 0 if time to move, 0 otherwise. // // *********************************************************************************************************************************************** SpeedCheck ldx 2 // Check in page 2 tma // Read speed iyc // Point to counter amaac // add speed to counter br SCTimeout // If true it's move time. tam // write counter back RetnY0 tcy 0 // Return Y = 0 retn SCTimeout tam // write back RetnY1 tcy 1 // Return Y = 1 retn // *********************************************************************************************************************************************** // // Has the object at (X,Y) collided with the buildings ? // // *********************************************************************************************************************************************** HeightCheck tma // Read the height into A iyc // Point to X tmy // Read horizontal position into Y ldx 1 // Point to the height table amaac // Add height to vertical height br RetnY1 // If S then reached the collision point br RetnY0 // otherwise no collision page // *********************************************************************************************************************************************** // // Check if objects are moving. // // *********************************************************************************************************************************************** CheckMoving tcy 6 // Check if bomb is moving lcall SpeedCheck // Bump the counter ynec 0 // Is it moving br CMMoveBomb // If so move the bomb. CMExit1 tcy 2 // Check if the bomber is moving. lcall SpeedCheck ldp CMMoveBomber ynec 0 br CMMoveBomber CMExit2 ldx 2 // Check if bomb is live (e.g. != 15) tcy 4 ldp CheckDropBomb imac br CheckDropBomb // If it is $F check dropping. CDBExit lbr MainRenderLoop // *********************************************************************************************************************************************** // Move the Bomb // *********************************************************************************************************************************************** CMMoveBomb tcy 4 // Point to Y imac // Bump Y position br CMExit1 // If was 15 (not in use) S will be set so don't move. tam lcall HeightCheck // Check if collided with building top. ynec 1 // If Y != 1 (Collision) br CMExit1 // End of moving bomb ldx 2 // Move to vertical position tcy 4 tcmiy 15 // Disable bomb and point at X position tmy // Put in Y ldx 1 // Point to height entry in the table tcmiy 0 // Write 0 there, e.g. building gone. ldx 0 // Point to sound timer tcy OSDSoundTimer tcmiy 5 // Play bomb sound. tcmiy 2 lbr OSIncrementOne // Bump score, then come back to the label below. OSExternalIncrementExit ldx 1 tcy 15 CheckAllFlattened mnez br CMExit1 dyn br CheckAllFlattened ldx 2 tcy 2 tcmiy 15 br CMExit1 // End of Ship Move. // *********************************************************************************************************************************************** // Move the Bomber // *********************************************************************************************************************************************** page CMMoveBomber tcy 1 // Point to X imac // Bump X and write back tam dan // S will be set unless zero br CMMBCheckHeight // if non-zero, then check height. tcy 0 // looped round, go down one. imac // Bump the vertical position. br WonGame // If carried over, then level is complete. tam CMMBCheckHeight tcy 0 lcall HeightCheck // Check for crash. ldp CMExit2 ynec 1 // If returned 0 br CMExit2 // end of turn, no crash. // Crash occurred, game over. LostGame ldx 0 // End game sound. tcy OSDSoundTimer tcmiy 15 tcmiy 2 tcy 0 // Win-lose flag will be 0 (lost) lbr WonGame2 WonGame ldx 0 // Beat level sound. tcy OSDSoundTimer tcmiy 15 tcmiy 7 tcy 1 // Win-lose flag will be 1 (won) WonGame2 tya // Flag in A. ldx 2 // Save win-lose flag. tcy 11 tam lbr RenderScore // *********************************************************************************************************************************************** // Check if bomb should be dropped // *********************************************************************************************************************************************** CheckDropBomb knez // Drop Bomb if key pressed br DropBomb lbr CDBExit DropBomb tcy 0 // Copy Bomber X+Y to Bomb X+Y tma tcy 4 tam tcy 1 tma tcy 5 tam ldx 0 // Point to sound timer tcy OSDSoundTimer tcmiy 2 // Play bomb drop sound. tcmiy 6 lbr CDBExit // *********************************************************************************************************************************************** // Level completed, or died (2,11) is '1' if the player compleeted the level. // *********************************************************************************************************************************************** page RenderScore tcy HWKeyMiddleCol rstr tcy HWKeyLeftCol // Select the left column which has the continue button. setr tcy 5 // Render the score at row 5 e.g. basically in the middle lbr OSUpdateAllAndRenderTextDisplay OSExternalRenderTextExit // And return here. knez // Is a key pressed ? br EndScore br RenderScore EndScore tcy HWKeyLeftCol // Select the left column which has the continue button. rstr ldx 2 // Look at win-lose tcy 11 ldp NextLevel // If win-lose set then next level mnez br NextLevel br ResetGame // otherwise restart.