diff --git a/Makefile b/Makefile index bd14c7d..711adcd 100644 --- a/Makefile +++ b/Makefile @@ -3,7 +3,7 @@ all : mandel.xex mandel.xex : mandel.o tables.o atari-asm-xex.cfg - ld65 -C ./atari-asm-xex.cfg -o $@ mandel.o tables.o + ld65 -C ./atari-asm-xex.cfg --mapfile mandel.map -o $@ mandel.o tables.o %.o : %.s ca65 -o $@ $< @@ -15,4 +15,6 @@ clean : rm -f tables.s rm -f *.o rm -f *.xex + rm -f mandel.map + diff --git a/mandel.s b/mandel.s index fc30532..b52f24a 100644 --- a/mandel.s +++ b/mandel.s @@ -1,43 +1,44 @@ ; Our zero-page vars -sx = $80 ; i16: screen pixel x -sy = $82 ; i16: screen pixel y -ox = $84 ; fixed4.12: center point x -oy = $86 ; fixed4.12: center point y -cx = $88 ; fixed4.12: c_x -cy = $8a ; fixed4.12: c_y -zx = $8c ; fixed4.12: z_x -zy = $8e ; fixed4.12: z_y +ox = $80 ; fixed6.26: center point x +oy = $84 ; fixed6.26: center point y +cx = $88 ; fixed6.26: c_x +cy = $8c ; fixed6.26: c_y -zx_2 = $90 ; fixed4.12: z_x^2 -zy_2 = $92 ; fixed4.12: z_y^2 -zx_zy = $94 ; fixed4.12: z_x * z_y -dist = $96 ; fixed4.12: z_x^2 + z_y^2 +zx = $90 ; fixed6.26: z_x +zy = $94 ; fixed6.26: z_y +zx_2 = $98 ; fixed6.26: z_x^2 +zy_2 = $9c ; fixed6.26: z_y^2 -iter = $a0 ; u8: iteration count +zx_zy = $a0 ; fixed6.26: z_x * z_y +dist = $a4 ; fixed6.26: z_x^2 + z_y^2 +sx = $a8 ; i16: screen pixel x +sy = $aa ; i16: screen pixel y +z_buffer_active = $ac ; boolean: 1 if we triggered the lake, 0 if not +z_buffer_start = $ad ; u8: index into z_buffer +z_buffer_end = $ae ; u8: index into z_buffer +iter = $af ; u8: iteration count -zoom = $a1 ; u8: zoom shift level -count_frames = $a2 ; u8 -count_pixels = $a3 ; u8 -total_ms = $a4 ; float48 -total_pixels = $aa ; float48 +ptr = $b0 ; u16 +pixel_ptr = $b2 ; u16 +zoom = $b4 ; u8: zoom shift level +fill_level = $b5 ; u8 +pixel_color = $b6 ; u8 +pixel_mask = $b7 ; u8 +pixel_shift = $b8 ; u8 +pixel_offset = $b9 ; u8 +palette_offset = $ba ; u8 +chroma_offset = $bb ; u8 +palette_ticks = $bc ; u8 +chroma_ticks = $bd ; u8 +count_frames = $be ; u8 +; free space $bf -z_buffer_active = $b0 ; boolean: 1 if we triggered the lake, 0 if not -z_buffer_start = $b1 ; u8: index into z_buffer -z_buffer_end = $b2 ; u8: index into z_buffer -temp = $b4 ; u16 -temp2 = $b6 ; u16 -pixel_ptr = $b8 ; u16 -pixel_color = $ba ; u8 -pixel_mask = $bb ; u8 -pixel_shift = $bc ; u8 -pixel_offset = $bd ; u8 -fill_level = $be ; u8 -palette_offset = $bf ; u8 - -palette_ticks = $c0 ; u8 -chroma_ticks = $c1 ; u8 -chroma_offset = $c2 ; u8 -ptr = $c4 ; u16 +count_iters = $c0 ; u16 +text_col = $c2 ; u8 +text_row = $c3 ; u8 +; free space c4-cb +temp = $cc ; u16 +temp2 = $ce ; u16 palette_delay = 23 chroma_delay = 137 @@ -60,10 +61,12 @@ LBUFF = $0580 ; result buffer for FASC routine ; FP ROM routine vectors FASC = $D8E6 ; FLOATING POINT TO ASCII (output in INBUFF, last char has high bit set) IFP = $D9AA ; INTEGER TO FLOATING POINT CONVERSION (FR0:u16 -> FR0:float48) +FPI = $D9D2 ; floating point to integer FADD = $DA66 ; ADDITION (FR0 += FR1) FSUB = $DA60 ; SUBTRACTION (FR0 -= FR1) FMUL = $DADB ; MULTIPLICATION (FR0 *= FR1) FDIV = $DB28 ; DIVISION (FR0 /= FR1) +ZFR0 = $DA44 ; clear FR0 ZF1 = $DA46 ; CLEAR ZERO PAGE FLOATING POINT NUMBER (XX) FLD0R = $DD89 ; LOAD FR0 WITH FLOATING POINT NUMBER (YYXX) FLD1R = $DD98 ; LOAD FR1 WITH FLOATING POINT NUMBER (YYXX) @@ -77,7 +80,7 @@ framebuffer_bottom = $b000 display_list = $bf00 framebuffer_end = $c000 -height = 184 +height = 176 half_height = height >> 1 width = 160 half_width = width >> 1 @@ -123,6 +126,10 @@ KEY_7 = 51 KEY_8 = 53 KEY_9 = 48 KEY_0 = 50 +KEY_PERIOD = 34 +KEY_E = 42 +KEY_X = 22 +KEY_Y = 43 .struct float48 exponent .byte @@ -141,25 +148,68 @@ strings: str_self: .byte "MANDEL-6502" str_self_end: + .byte 0 str_speed: - .byte " ms/px" + .byte "us/iter: " str_speed_end: + .byte 0 str_run: .byte " RUN" str_run_end: + .byte 0 str_done: .byte "DONE" str_done_end: + .byte 0 +str_padding: + .byte " " +str_padding_end: + .byte 0 + +str_space: + .byte " " + .byte 0 + +str_h: + .byte "h" + .byte 0 +str_m: + .byte "m" + .byte 0 +str_s: + .byte "s" + .byte 0 -str_self_len = str_self_end - str_self str_speed_len = str_speed_end - str_speed str_run_len = str_run_end - str_run str_done_len = str_done_end - str_done -speed_precision = 6 +str_padding_len = str_padding_end - str_padding -speed_start = 40 - str_done_len - str_speed_len - speed_precision - 1 -speed_len = 14 + str_speed_len +; "3h59m59s" +str_elapsed_spacer = 8 +speed_start = 40 - str_done_len - str_speed_len - str_padding_len - str_elapsed_spacer - 1 +col_x = 1 +str_x: + .byte "X:" + .byte 0 +str_x_len = 2 +str_x_space = 12 +str_x_padding = 2 + +col_y = col_x + str_x_len + str_x_space + str_x_padding +str_y: + .byte "Y:" + .byte 0 +str_y_len = 2 +str_y_space = 12 +str_y_padding = 2 + +col_zoom = col_y + str_y_len + str_y_space + str_y_padding +str_zoom: + .byte "ZOOM:" + .byte 0 +str_zoom_len = 5 char_map: ; Map ATASCII string values to framebuffer font entries @@ -175,8 +225,12 @@ char_map: .endrepeat hex_chars: +digits_zero: .byte "0123456789abcdef" +digits_space: + .byte " 123456789abcdef" + aspect: ; aspect ratio! ; pixels at 320w are 5:6 (narrow) @@ -190,20 +244,49 @@ aspect: ; ; 184h is the equiv of 220.8h at square pixels ; 320 / 220.8 = 1.45 display aspect ratio -aspect_x: ; fixed4.16 5/4 - .word 5 << (12 - 2) +aspect_x: ; fixed3.13 5/4 + .word 5 << (13 - 2) -aspect_y: ; fixed4.16 3/4 - .word 3 << (12 - 2) +aspect_y: ; fixed3.13 3/4 + .word 3 << (13 - 2) -ms_per_frame: ; float48 16.66666667 - .byte 64 ; exponent/sign - .byte $16 ; BCD digits +fixed3_13_as_float: ; float48 + ; 1 << 13 + ; 8192 + ; 81 92 . 00 00 00 + .byte 65 ; exponent/sign - +1 byte + .byte $81 + .byte $92 + .byte $00 + .byte $00 + .byte $00 + +sec_per_frame: ; float48 00 . 01 66 66 66 67 + .byte 63 ; exponent/sign - -1 bytes + .byte $01 ; BCD digits .byte $66 .byte $66 .byte $66 .byte $67 +us_per_sec: ; float48 1e9 01 00 0,0 00 . 00 + .byte 67 ; exponent/sign +3 bytes + .byte $01 ; BCD digits + .byte $00 + .byte $00 + .byte $00 + .byte $00 + +total_iters: ; float48 + .repeat 6 + .byte 0 + .endrepeat + +total_sec: ; float48 + .repeat 6 + .byte 0 + .endrepeat + display_list_start: ; 24 lines overscan .repeat 3 @@ -227,6 +310,10 @@ display_list_start: .byte $0e .endrep + ; 8 scan lines, 1 row of 40-column text + .byte $42 + .addr textbuffer + 40 + .byte $41 ; jump and blank .addr display_list display_list_end: @@ -235,9 +322,9 @@ display_list_len = display_list_end - display_list_start color_map: .byte 0 .repeat 85 - .byte 1 - .byte 2 - .byte 3 + .byte %01010101 + .byte %10101010 + .byte %11111111 .endrepeat @@ -286,23 +373,46 @@ fill_masks: .byte %00000001 .byte %00000000 +pixel_masks: + .byte %11111111 + .byte %11110000 + .byte %11000000 + viewport_zoom: - .byte 1 - .byte 6 - .byte 8 - .byte 6 + .byte 0 + .byte 5 + .byte 7 + .byte 5 + .byte 7 + .byte 7 viewport_ox: - .word $0000 - .word $f110 - .word $f110 - .word $e400 + .dword ($00000000 & $3fffffff) << 2 + .dword ($ff110000 & $3fffffff) << 2 + .dword ($ff110000 & $3fffffff) << 2 + .dword ($fe400000 & $3fffffff) << 2 + .dword ($fe3b0000 & $3fffffff) << 2 + .dword $fd220000 viewport_oy: - .word $0000 - .word $fb60 - .word $fbe0 - .word $0000 + .dword ($00000000 & $3fffffff) << 2 + .dword ($ffb60000 & $3fffffff) << 2 + .dword ($ffbe0000 & $3fffffff) << 2 + .dword ($00000000 & $3fffffff) << 2 + .dword ($fffe0000 & $3fffffff) << 2 + .dword $ff000000 + +elapsed_work: + .dword 0 +elapsed_digit: + .byte 0 + +input_col: + .byte 0 +input_row: + .byte 0 +input_max: + .byte 0 ; 2 + 9 * byte cycles .macro add bytes, dest, arg1, arg2 @@ -321,7 +431,7 @@ viewport_oy: ; 38 cycles .macro add32 dest, arg1, arg2 - add 4, dest, arg2, dest + add 4, dest, arg1, arg2 .endmacro ; 8 cycles @@ -351,7 +461,7 @@ viewport_oy: sub 4, dest, arg1, arg2 .endmacro -; 3 + 5 * bytes cycles +; 3 + 5 * (bytes - 1) cycles .macro shl bytes, arg asl arg ; 3 cyc .repeat bytes-1, i @@ -359,22 +469,23 @@ viewport_oy: .endrepeat .endmacro -; 13 cycles +; 8 cycles .macro shl16 arg shl 2, arg .endmacro -; 18 cycles +; 13 cycles .macro shl24 arg shl 3, arg .endmacro -; 23 cycles +; 18 cycles .macro shl32 arg shl 4, arg .endmacro ; 6 * bytes cycles +; 4 * bytes bytes .macro copy bytes, dest, arg .repeat bytes, byte ; 6 * bytes cycles lda arg + byte ; 3 cyc @@ -383,6 +494,7 @@ viewport_oy: .endmacro ; 12 cycles +; 8 bytes .macro copy16 dest, arg copy 2, dest, arg .endmacro @@ -417,31 +529,38 @@ viewport_oy: neg 4, arg .endmacro -; 11-27 + 23 * shift cycles -; 103-119 cycles for shift=4 +; 11-27 + 18 * shift cycles +; 65-81 cycles for shift=3 .macro shift_round_16 arg, shift .repeat shift - shl32 arg ; 23 cycles + shl32 arg ; 18 cycles .endrepeat round16 arg ; 11-27 cycles .endmacro -.macro imul16_round dest, arg1, arg2, shift +; input: arg1, arg2 as fixed4.12 +; output: dest as fixed8.24 +; patch point jsr at 16 bytes in +imul16_patch_offset = 16 +.macro imul16 dest, arg1, arg2 copy16 FR0, arg1 ; 12 cyc copy16 FR1, arg2 ; 12 cyc jsr imul16_func ; ? cyc - shift_round_16 FR2, shift ; 103-119 cycles for shift=4 - copy16 dest, FR2 + 2 ; 12 cyc + copy32 dest, FR2 ; 24 cyc .endmacro -.macro sqr16_round dest, arg, shift - ;imul16_round dest, arg, arg, shift +; input: arg as fixed4.12 +; output: dest as fixed8.24 +; patch point jsr at 8 bytes in +sqr16_patch_offset = 8 +.macro sqr16 dest, arg copy16 FR0, arg ; 12 cyc - jsr sqr16_func ; ? cyc - shift_round_16 FR2, shift ; 103-119 cycles for shift=4 - copy16 dest, FR2 + 2 ; 12 cyc + jsr sqr16_func ; ? cyc + copy32 dest, FR2 ; 24 cyc .endmacro +; input: arg as u8 +; output: dest as u16 ; clobbers a, x .macro sqr8 dest, arg ldx arg @@ -451,18 +570,6 @@ viewport_oy: sta dest + 1 .endmacro -; clobbers a, x -.macro sqr8_add16 dest, arg - ldx arg - clc - lda sqr_lobyte,x - adc dest - sta dest - lda sqr_hibyte,x - adc dest + 1 - sta dest + 1 -.endmacro - .segment "TABLES" ; lookup table for top byte -> PORTB value for bank-switch .align 256 @@ -591,71 +698,6 @@ bank_switch_table: .endif .endmacro -.proc imul8xe_init - - bank_switch 0 - lda #0 - sta EXTENDED_RAM - bank_switch 1 - lda #1 - sta EXTENDED_RAM - bank_switch 0 - lda EXTENDED_RAM - beq init - - ; no bank switching available, we just overwrite the value in base ram - rts - -init: - - ; patch imul16_func into a forwarding thunk to imul16xe_func - lda #$4c ; 'jmp' opcode - sta imul16_func - lda #.lobyte(imul16xe_func) - sta imul16_func + 1 - lda #.hibyte(imul16xe_func) - sta imul16_func + 2 - - ; ditto for sqr16_func -> sqr16xe_func - lda #$4c ; 'jmp' opcode - sta sqr16_func - lda #.lobyte(sqr16xe_func) - sta sqr16_func + 1 - lda #.hibyte(sqr16xe_func) - sta sqr16_func + 2 - - ; create the lookup table - ; go through the input set, in four 16KB chunks - - arg1 = FR1 - arg2 = FR2 - result = FR0 - - lda #$00 - sta arg1 - sta arg2 - sta ptr - lda #$40 - sta ptr + 1 - - ; $00 * $00 -> $3f * $ff - bank_switch 0 - jsr imul8xe_init_section - - ; $40 * $00 -> $7f * $ff - bank_switch 1 - jsr imul8xe_init_section - - ; $80 * $00 -> $bf * $ff - bank_switch 2 - jsr imul8xe_init_section - - ; $c0 * $00 -> $ff * $ff - bank_switch 3 - jsr imul8xe_init_section - - rts -.endproc ; Initialize a 16 KB chunk of the table ; input: multipliers in temp @@ -745,9 +787,8 @@ inner_loop: ; h1*h2*256*256 + h1*l2*256 + h2*l1*256 + l1*l2 imul8 result, arg1, arg2, xe - lda #0 - sta result + 2 - sta result + 3 + + imul8 result + 2, arg1 + 1, arg2 + 1, xe imul8 inter, arg1 + 1, arg2, xe add16 result + 1, result + 1, inter @@ -757,9 +798,6 @@ inner_loop: add16 result + 1, result + 1, inter add_carry result + 3 - imul8 inter, arg1 + 1, arg2 + 1, xe - add16 result + 2, result + 2, inter - ; In case of negative inputs, adjust high word ; https://stackoverflow.com/a/28827013 lda arg1 + 1 @@ -792,9 +830,8 @@ arg2_pos: ; h*h*256*256 + h*l*256 + h*l*256 + l*l sqr8 result, arg - lda #0 - sta result + 2 - sta result + 3 + + sqr8 result + 2, arg + 1 imul8 inter, arg + 1, arg, xe add16 result + 1, result + 1, inter @@ -802,8 +839,6 @@ arg2_pos: add16 result + 1, result + 1, inter add_carry result + 3 - sqr8_add16 result + 2, arg + 1 - rts ; 6 cyc .endscope .endmacro @@ -869,10 +904,83 @@ next: .endmacro +; input in FR0, 16 bits signed 3.13 fixed +; output in FR0, Atari float +; clobbers a, x, y, FR0, FR1 +.proc fixed3_13_to_float + ldx #.lobyte(fixed3_13_as_float) + ldy #.hibyte(fixed3_13_as_float) + jsr FLD1R + + ; check sign bit! conversion routine is for unsigned + lda FR0 + 1 + bpl positive + +negative: + neg16 FR0 + jsr IFP + + ; set float sign bit + lda FR0 + ora #$80 + sta FR0 + jmp common + +positive: + jsr IFP + +common: + jsr FDIV + rts + +.endproc + +; rounds to 16-bit first! +; input in FR0, 32 bits signed 6.26 fixed +; output in FR0, Atari float +; clobbers a, x, y, FR0, FR1 +.proc fixed6_26_to_float + shift_round_16 FR0, 3 + copy16 FR0, FR0 + 2 + jsr fixed3_13_to_float + rts +.endproc + +; input in FR0, Atari float +; output in FR0, 16 bits signed 3.13 fixed +; clobbers a, x, y, FR0, FR1 +.proc float_to_fixed3_13 + ldx #.lobyte(fixed3_13_as_float) + ldy #.hibyte(fixed3_13_as_float) + jsr FLD1R + jsr FMUL + + ; check sign bit! conversion routine is for unsigned + lda FR0 + bcc positive + +negative: + ; clearfloat sign bit + lda FR0 + eor #$80 + sta FR0 + + jsr FPI + neg16 FR0 + jmp common + +positive: + jsr FPI + +common: + rts + +.endproc + .proc mandelbrot ; input: - ; cx: position scaled to 4.12 fixed point - -8..+7.9 - ; cy: position scaled to 4.12 + ; cx: position scaled to 6.26 fixed point - -32..+31.9 + ; cy: position scaled to 6.26 ; ; output: ; iter: iteration count at escape or 0 @@ -884,16 +992,50 @@ next: ; zx_zy = 0 ; dist = 0 ; iter = 0 +; lda #00 +; ldx #(iter - zx + 1) +;initloop: +; sta zx - 1,x +; dex +; bne initloop +; sta z_buffer_start +; sta z_buffer_end + lda #00 - ldx #(iter - zx + 1) -initloop: - sta zx - 1,x - dex - bne initloop + sta zx + sta zx + 1 + sta zx + 2 + sta zx + 3 + sta zy + sta zy + 1 + sta zy + 2 + sta zy + 3 + sta zx_2 + sta zx_2 + 1 + sta zx_2 + 2 + sta zx_2 + 3 + sta zy_2 + sta zy_2 + 1 + sta zy_2 + 2 + sta zy_2 + 3 + sta zx_zy + sta zx_zy + 1 + sta zx_zy + 2 + sta zx_zy + 3 + sta dist + sta dist + 1 + sta dist + 2 + sta dist + 3 + sta iter sta z_buffer_start sta z_buffer_end loop: + inc count_iters + bne low_iters + inc count_iters + 1 +low_iters: + ; iter++ & max-iters break inc iter bne keep_going @@ -901,6 +1043,8 @@ loop: keep_going: .macro quick_exit arg, max + ; arg: fixed6.26 + ; max: integer .local positive .local negative .local nope_out @@ -908,51 +1052,64 @@ keep_going: .local all_done ; check sign bit - lda arg + 1 + lda arg + 3 bmi negative positive: - cmp #((max) << 4) + cmp #(max << 2) bmi all_done ; 'less than' jmp exit_path negative: - cmp #(256 - ((max) << 4)) + cmp #(256 - (max << 2)) beq first_equal ; 'equal' on first byte bpl all_done ; 'greater than' nope_out: jmp exit_path - + first_equal: + ; following bytes all 0 shows it's really 'equal' + lda arg + 2 + bne all_done + lda arg + 1 + bne all_done lda arg - beq nope_out ; 2nd byte 0 shows it's really 'equal' + bne all_done + jmp exit_path all_done: .endmacro - ; 4.12: (-8 .. +7.9) + ; 6.26: (-32 .. 31.9) ; zx = zx_2 - zy_2 + cx - sub16 zx, zx_2, zy_2 - add16 zx, zx, cx + sub32 zx, zx_2, zy_2 + add32 zx, zx, cx quick_exit zx, 2 ; zy = zx_zy + zx_zy + cy - add16 zy, zx_zy, zx_zy - add16 zy, zy, cy + add32 zy, zx_zy, zx_zy + add32 zy, zy, cy quick_exit zy, 2 + ; convert 6.26 -> 3.13: (-4 .. +3.9) + shift_round_16 zx, 3 + shift_round_16 zy, 3 + ; zx_2 = zx * zx - sqr16_round zx_2, zx, 4 +fixup_sqr16_1: + sqr16 zx_2, zx + 2 ; zy_2 = zy * zy - sqr16_round zy_2, zy, 4 +fixup_sqr16_2: + sqr16 zy_2, zy + 2 ; zx_zy = zx * zy - imul16_round zx_zy, zx, zy, 4 +fixup_imul16_1: + imul16 zx_zy, zx + 2, zy + 2 ; dist = zx_2 + zy_2 - add16 dist, zx_2, zy_2 + add32 dist, zx_2, zy_2 quick_exit dist, 4 ; if may be in the lake, look for looping output with a small buffer @@ -989,10 +1146,10 @@ z_buffer_loop: ; Compare the previously stored z values ldy #0 - z_compare zx - z_compare zx + 1 - z_compare zy - z_compare zy + 1 + z_compare zx + 2 + z_compare zx + 3 + z_compare zy + 2 + z_compare zy + 3 cpy #4 bne z_no_matches @@ -1007,10 +1164,10 @@ z_no_matches: z_nothing_to_read: ; Store and expand - z_store zx - z_store zx + 1 - z_store zy - z_store zy + 1 + z_store zx + 2 + z_store zx + 3 + z_store zy + 2 + z_store zy + 3 z_advance stx z_buffer_end @@ -1061,14 +1218,17 @@ cont: enough: .endmacro -.macro zoom_factor dest, src, zoom, aspect +.macro zoom_factor dest, src, aspect + ; output: dest: fixed6.26 + ; input: src: fixed3.13 + ; aspect: fixed3.13 ; clobbers A, X, flags, etc copy16 dest, src scale_zoom dest ; cy = cy * (3 / 4) ; cx = cx * (5 / 4) - imul16_round dest, dest, aspect, 4 + imul16 dest, dest, aspect .endmacro .proc pset @@ -1079,8 +1239,11 @@ enough: ; iter -> color ldx iter lda color_map,x + ldx fill_level + and pixel_masks,x sta pixel_color - lda #(255 - 3) + lda pixel_masks,x + eor #$ff sta pixel_mask ; sy -> line base address in temp @@ -1129,22 +1292,23 @@ point: ; pixel_mask <<= pixel_shift (shifting in ones) and #3 sta pixel_shift - lda #3 - sec - sbc pixel_shift tax shift_loop: beq shift_done - asl pixel_color - asl pixel_color + lsr pixel_color + lsr pixel_color sec - rol pixel_mask + ror pixel_mask sec - rol pixel_mask + ror pixel_mask dex jmp shift_loop shift_done: + ldy fill_level + ldx fill_masks,y + inx + ; pixel_offset = temp >> 2 lda temp lsr a @@ -1152,48 +1316,94 @@ shift_done: sta pixel_offset tay +draw_pixel: ; read, mask, or, write lda (pixel_ptr),y and pixel_mask ora pixel_color sta (pixel_ptr),y + dex + beq done + clc + lda #40 + adc pixel_ptr + sta pixel_ptr + lda #0 + adc pixel_ptr + 1 + sta pixel_ptr + 1 + jmp draw_pixel + +done: rts .endproc -.macro draw_text_indirect col, len, strptr - ; clobbers A, X - .local loop - .local done - ldx #0 -loop: - cpx #len - beq done - txa - tay - lda (strptr),y - tay - lda char_map,y - sta textbuffer + col,x - inx - jmp loop -done: -.endmacro +; in/out: column in text_col +; in: row in text_row +; in: pointer to string in INBUFF +; clobbers x/y/a/temp +.proc draw_string + drawptr = temp + strptr = INBUFF -.macro draw_text col, len, cstr - ; clobbers A, X - .local loop - .local done - ldx #0 + clc + lda #.lobyte(textbuffer) + adc text_col + sta temp + lda #.hibyte(textbuffer) + adc #0 + sta temp + 1 + + ldx text_row + beq done_rows +continue_rows: + clc + lda temp + adc #40 + sta temp + lda temp + 1 + adc #0 + sta temp + 1 + dex + bne continue_rows + +done_rows: + + ldy #0 loop: - cpx #len + lda (strptr),y + ; if char's null, terminate c-style beq done - ldy cstr,x - lda char_map,y - sta textbuffer + col,x - inx + ; save the char for terminator check + pha + ; strip the high bit (terminator) + and #$7f + tax + lda char_map,x + sta (drawptr),y + iny + + pla + ; _last_ char has high bit set in atari rom routines + bmi done jmp loop + done: + ; move the text column pointer + tya + clc + adc text_col + sta text_col + + rts +.endproc + +.macro draw_string_const str + lda #.lobyte(str) + sta INBUFF + lda #.hibyte(str) + sta INBUFF + 1 + jsr draw_string .endmacro .proc vblank_handler @@ -1293,12 +1503,15 @@ skip_luma: cpy #KEY_MINUS beq minus - ; temp = $0010 << (8 - zoom) - lda #$10 - sta temp + ; temp+temp2 = $00010000 << (8 - zoom) lda #$00 + sta temp sta temp + 1 - scale_zoom temp + lda #$01 + sta temp + 2 + lda #$00 + sta temp + 3 + scale_zoom temp + 2 cpy #KEY_UP beq up @@ -1308,14 +1521,7 @@ skip_luma: beq left cpy #KEY_RIGHT beq right - cpy #KEY_1 - beq one - cpy #KEY_2 - beq two - cpy #KEY_3 - beq three - cpy #KEY_4 - beq four + jmp number_keys skip_char: lda #0 @@ -1323,7 +1529,7 @@ skip_char: plus: lda zoom - cmp #8 + cmp #7 bpl skip_char inc zoom jmp done @@ -1334,17 +1540,37 @@ minus: dec zoom jmp done up: - sub16 oy, oy, temp + add32 oy, oy, temp + jsr display_coords jmp done down: - add16 oy, oy, temp + sub32 oy, oy, temp + jsr display_coords jmp done left: - sub16 ox, ox, temp + sub32 ox, ox, temp + jsr display_coords jmp done right: - add16 ox, ox, temp + add32 ox, ox, temp + jsr display_coords jmp done + +number_keys: + cpy #KEY_1 + beq one + cpy #KEY_2 + beq two + cpy #KEY_3 + beq three + cpy #KEY_4 + beq four + cpy #KEY_5 + beq five + cpy #KEY_6 + beq six + jmp letter_keys + one: ldx #0 jmp load_key_viewport @@ -1356,7 +1582,27 @@ three: jmp load_key_viewport four: ldx #3 - ; fall through + jmp load_key_viewport +five: + ldx #4 + jmp load_key_viewport +six: + ldx #5 + jmp load_key_viewport + +letter_keys: + cpy #KEY_X + bne not_x + jsr input_x + jmp done +not_x: + cpy #KEY_Y + bne not_y + jsr input_y + jmp done +not_y: + jmp skip_char + load_key_viewport: jsr load_viewport ; fall through @@ -1366,6 +1612,23 @@ done: .endproc +.proc input_x + ldx #col_x + ldy #1 + jsr input_number + + + rts +.endproc + +.proc input_y + rts +.endproc + +.proc input_number + rts +.endproc + .proc clear_screen ; zero the range from framebuffer_top to display_list lda #.lobyte(framebuffer_top) @@ -1391,12 +1654,59 @@ zero_byte_loop: .proc status_bar ; Status bar - draw_text 0, str_self_len, str_self - draw_text 40 - str_run_len, str_run_len, str_run + + lda #0 + sta text_col + lda #0 + sta text_row + draw_string_const str_self + + lda #(40 - str_run_len) + sta text_col + draw_string_const str_run rts .endproc +.proc display_coords + lda #1 + sta text_row + lda #col_x + sta text_col + draw_string_const str_x + + copy32 FR0, ox + jsr fixed6_26_to_float + jsr FASC + jsr draw_string + + lda #col_y + sta text_col + draw_string_const str_y + + copy32 FR0, oy + jsr fixed6_26_to_float + jsr FASC + jsr draw_string + + lda #col_zoom + sta text_col + draw_string_const str_zoom + + lda zoom + clc + adc #0 + sta FR0 + lda #0 + sta FR0 + 1 + jsr IFP + jsr FASC + jsr draw_string + + rts + +.endproc + ; input: viewport selector in x ; clobbers: a, x .proc load_viewport @@ -1406,17 +1716,32 @@ zero_byte_loop: txa asl a + asl a + tax lda viewport_ox,x sta ox lda viewport_oy,x sta oy + inx lda viewport_ox,x sta ox + 1 lda viewport_oy,x sta oy + 1 + inx + lda viewport_ox,x + sta ox + 2 + lda viewport_oy,x + sta oy + 2 + + inx + lda viewport_ox,x + sta ox + 3 + lda viewport_oy,x + sta oy + 3 + rts .endproc @@ -1433,6 +1758,7 @@ zero_byte_loop: sta DMACTL jsr clear_screen + jsr display_coords ; Copy the display list into properly aligned memory ; Can't cross 1024-byte boundaries :D @@ -1471,19 +1797,24 @@ copy_byte_loop: jsr SETVBV main_loop: - ; count_frames = 0; count_pixels = 0 + ; count_frames = 0; count_iters = 0 lda #0 sta count_frames - sta count_pixels + sta count_iters + sta count_iters + 1 - ; total_ms = 0.0; total_pixels = 0.0 - ldx #total_ms - jsr ZF1 - ldx #total_pixels - jsr ZF1 + ; total_sec = 0.0; total_iters = 0.0 + jsr ZFR0 + ldx #.lobyte(total_sec) + ldy #.hibyte(total_sec) + jsr FST0R + ldx #.lobyte(total_iters) + ldy #.hibyte(total_iters) + jsr FST0R jsr clear_screen jsr status_bar + jsr display_coords lda #0 sta fill_level @@ -1538,10 +1869,11 @@ skipped_mask: not_skipped_mask: ; run the fractal! - zoom_factor cx, sx, zoom, aspect_x - add16 cx, cx, ox - zoom_factor cy, sy, zoom, aspect_y - add16 cy, cy, oy + zoom_factor cx, sx, aspect_x + add32 cx, cx, ox + zoom_factor cy, sy, aspect_y + neg32 cy + add32 cy, cy, oy jsr mandelbrot jsr pset @@ -1552,38 +1884,32 @@ not_skipped_mask: no_key: ; check if we should update the counters - ; - ; count_pixels >= width? update! - inc count_pixels - lda count_pixels - cmp #width - bmi update_status ; count_frames >= 120? update! lda count_frames cmp #120 ; >= 2 seconds - bmi skipped + bpl update_status + jmp skipped update_status: - ; FR0 = (float)count_pixels & clear count_pixels - lda count_pixels - sta FR0 - lda #0 - sta FR0 + 1 - sta count_pixels + ; FR0 = (float)count_iters & clear count_iters + copy16 FR0, count_iters jsr IFP + lda #0 + sta count_iters + sta count_iters + 1 - ; FR1 = total_pixels - ldx #.lobyte(total_pixels) - ldy #.hibyte(total_pixels) + ; FR1 = total_iters + ldx #.lobyte(total_iters) + ldy #.hibyte(total_iters) jsr FLD1R ; FR0 += FR1 jsr FADD - ; total_pixels = FR0 - ldx #.lobyte(total_pixels) - ldy #.hibyte(total_pixels) + ; total_iters = FR0 + ldx #.lobyte(total_iters) + ldy #.hibyte(total_iters) jsr FST0R @@ -1596,44 +1922,100 @@ update_status: sta count_frames jsr IFP - ; FR0 *= ms_per_frame - ldx #.lobyte(ms_per_frame) - ldy #.hibyte(ms_per_frame) + ; FR0 *= sec_per_frame + ldx #.lobyte(sec_per_frame) + ldy #.hibyte(sec_per_frame) jsr FLD1R jsr FMUL - ; FR0 += total_ms - ldx #total_ms - ldy #0 + ; FR0 += total_sec + ldx #.lobyte(total_sec) + ldy #.hibyte(total_sec) jsr FLD1R jsr FADD - ; total_ms = FR0 - ldx #total_ms - ldy #0 + ; total_sec = FR0 + ldx #.lobyte(total_sec) + ldy #.hibyte(total_sec) jsr FST0R - ; FR0 /= total_pixels - ldx #total_pixels - ldy #0 + ; FR0 /= total_iters + ldx #.lobyte(total_iters) + ldy #.hibyte(total_iters) jsr FLD1R jsr FDIV - ; convert to ASCII in INBUFF - jsr FASC + ; FR0 *= us_per_sec + ldx #.lobyte(us_per_sec) + ldy #.hibyte(us_per_sec) + jsr FLD1R + jsr FMUL - ; print the first 6 digits - draw_text_indirect speed_start, speed_precision, INBUFF - draw_text speed_start + speed_precision, str_speed_len, str_speed + ; round (down) to integer + jsr FPI + clc + jsr IFP + + lda #speed_start + sta text_col + lda #0 + sta text_row + draw_string_const str_speed + + lda text_col + pha + draw_string_const str_padding + pla + sta text_col + + ; convert to ASCII in INBUFF and print + jsr FASC + jsr draw_string + + ; elapsed time + ; FR0 = total_sec + ldx #.lobyte(total_sec) + ldy #.hibyte(total_sec) + jsr FLD0R + ; FR0 -> integer -> elapsed_work + jsr FPI + lda FR0 + sta elapsed_work + lda FR0 + 1 + sta elapsed_work + 1 + + draw_string_const str_space + + .macro do_countdown divisor, digits + ldx #.lobyte(divisor) + ldy #.hibyte(divisor) + lda #.lobyte(digits) + sta INBUFF + lda #.hibyte(digits) + sta INBUFF + 1 + jsr countdown + .endmacro + do_countdown 36000, digits_space + do_countdown 3600, digits_zero + draw_string_const str_h + do_countdown 600, digits_zero + do_countdown 60, digits_zero + draw_string_const str_m + do_countdown 10, digits_zero + do_countdown 1, digits_zero + draw_string_const str_s skipped: + ; sx += fill_level[fill_masks] + 1 + ldx fill_level + lda fill_masks,x clc - lda sx - adc #1 + adc #1 ; will never carry + adc sx sta sx - lda sx + 1 - adc #0 + lda #0 + adc sx + 1 sta sx + 1 lda sx @@ -1643,12 +2025,15 @@ skipped: loop_sx_done: + ; sy += fill_level[fill_masks] + 1 + ldx fill_level + lda fill_masks,x clc - lda sy - adc #1 + adc #1 ; will never carry + adc sy sta sy - lda sy + 1 - adc #0 + lda #0 + adc sy + 1 sta sy + 1 lda sy @@ -1667,9 +2052,130 @@ fill_loop_done: loop: ; finished - draw_text 40 - str_done_len, str_done_len, str_done + + lda #(40 - str_done_len) + sta text_col + lda #0 + sta text_row + draw_string_const str_done + jsr keycheck beq loop jmp main_loop .endproc + +; digit string in INBUFF +; divisor X/Y +; clobbers temp, calls draw_string +.proc countdown + divisor = temp + stx divisor + sty divisor + 1 + + ; count the hours + ldy #0 +countdown_loop: + lda elapsed_work + 1 + cmp divisor + 1 + beq countdown_lobyte + bcc countdown_done + bcs countdown_inc +countdown_lobyte: + lda elapsed_work + cmp divisor + bcc countdown_done +countdown_inc: + sec + lda elapsed_work + sbc divisor + sta elapsed_work + lda elapsed_work + 1 + sbc divisor + 1 + sta elapsed_work + 1 + iny + jmp countdown_loop +countdown_done: + lda (INBUFF),y + eor #$80 + sta elapsed_digit + lda #.lobyte(elapsed_digit) + sta INBUFF + lda #.hibyte(elapsed_digit) + sta INBUFF + 1 + jsr draw_string + rts +.endproc + +.proc imul8xe_init + + bank_switch 0 + lda #0 + sta EXTENDED_RAM + bank_switch 1 + lda #1 + sta EXTENDED_RAM + bank_switch 0 + lda EXTENDED_RAM + beq init + + ; no bank switching available, we just overwrite the value in base ram + rts + +init: + + ; patch imul16_func into a forwarding thunk to imul16xe_func + lda #$4c ; 'jmp' opcode + sta imul16_func + lda #.lobyte(imul16xe_func) + sta imul16_func + 1 + sta mandelbrot::fixup_imul16_1 + imul16_patch_offset + 1 + lda #.hibyte(imul16xe_func) + sta imul16_func + 2 + sta mandelbrot::fixup_imul16_1 + imul16_patch_offset + 2 + + ; ditto for sqr16_func -> sqr16xe_func + lda #$4c ; 'jmp' opcode + sta sqr16_func + lda #.lobyte(sqr16xe_func) + sta sqr16_func + 1 + sta mandelbrot::fixup_sqr16_1 + sqr16_patch_offset + 1 + sta mandelbrot::fixup_sqr16_2 + sqr16_patch_offset + 1 + lda #.hibyte(sqr16xe_func) + sta sqr16_func + 2 + sta mandelbrot::fixup_sqr16_1 + sqr16_patch_offset + 2 + sta mandelbrot::fixup_sqr16_2 + sqr16_patch_offset + 2 + + + ; create the lookup table + ; go through the input set, in four 16KB chunks + + arg1 = FR1 + arg2 = FR2 + result = FR0 + + lda #$00 + sta arg1 + sta arg2 + sta ptr + lda #$40 + sta ptr + 1 + + ; $00 * $00 -> $3f * $ff + bank_switch 0 + jsr imul8xe_init_section + + ; $40 * $00 -> $7f * $ff + bank_switch 1 + jsr imul8xe_init_section + + ; $80 * $00 -> $bf * $ff + bank_switch 2 + jsr imul8xe_init_section + + ; $c0 * $00 -> $ff * $ff + bank_switch 3 + jsr imul8xe_init_section + + rts +.endproc diff --git a/readme.md b/readme.md index f297d60..2c9efc1 100644 --- a/readme.md +++ b/readme.md @@ -18,7 +18,7 @@ Enjoy! I'll probably work on this off and on for the next few weeks until I've g ## Current state -Basic rendering is functional, with interactive zoom/pan (+/-/arrows) and 4 preset viewports via the number keys. +Basic rendering is functional, with interactive zoom/pan (+/-/arrows) and 6 preset viewports via the number keys. The 16-bit signed integer multiplication takes two 16-bit inputs and emits one 32-bit output in the zero page, using the Atari OS ROM's floating point registers as workspaces. Inputs are clobbered. @@ -27,7 +27,7 @@ The 16-bit signed integer multiplication takes two 16-bit inputs and emits one 3 * when expanded RAM is available as on 130XE, a 64KB 8-bit multiplication table accelerates the remaining multiplications * without expanded RAM, a table of half-squares is used to implement the algorithm from https://everything2.com/title/Fast+6502+multiplication -The mandelbrot calculations are done using 4.12-precision fixed point numbers. It may be possible to squish this down to 3.13. +The mandelbrot calculations are done using 3.13-precision fixed point numbers with 6.26-precision intermediates. Iterations are capped at 255. @@ -47,4 +47,4 @@ Currently produces a `.xex` executable, which can be booted up in common Atari e ## Todo -See ideas in `todo.md`. \ No newline at end of file +See ideas in `todo.md`. diff --git a/todo.md b/todo.md index 1281de7..6807ae2 100644 --- a/todo.md +++ b/todo.md @@ -1,15 +1,17 @@ things to try: +* fix status bar to show elapsed time, per-iter time, per-pixel iter count + +* 'turbo' mode disabling graphics in full or part + * patch the entire expanded-ram imul8xe on top of imul8 to avoid the 3-cycle thunk penalty :D -* try 3.13 fixed point instead of 4.12 for more precision - * can we get away without the extra bit? +* maybe clean up the load/layout of the big mul table + +* consider alternate lookup tables in the top 16KB under ROM * y-axis mirror optimization -* 'wide pixels' 2x and 4x for a fuller initial image in the tiered rendering - * maybe redo tiering to just 4x4, 2x2, 1x1? - * extract viewport for display & re-input via keyboard * fujinet screenshot/viewport uploader