99 lines
1.5 KiB
ArmAsm
99 lines
1.5 KiB
ArmAsm
;===============================
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; rotate intro -- rotate screen
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;===============================
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rotate_intro:
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; first copy current screen to background
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jsr gr_copy_current_to_offscreen_40x40
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; int xx,yy,color,x2,y2;
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; double h,theta,dx,dy,theta2,thetadiff,nx,ny;
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; int i;
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; gr_copy(0x400,0xc00);
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; gr_copy_to_current(0xc00);
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; page_flip();
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; gr_copy_to_current(0xc00);
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; page_flip();
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; thetadiff=0;
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; for(i=0;i<8;i++) {
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; for(yy=0;yy<40;yy++) {
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; for(xx=0;xx<40;xx++) {
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; dx=(xx-20);
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; dy=(yy-20);
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; h=sqrt((dx*dx)+(dy*dy));
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; theta=atan2(dy,dx);
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;
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; theta2=theta+thetadiff;
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; nx=h*cos(theta2);
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; ny=h*sin(theta2);
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;
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; x2=nx+20;
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; y2=ny+20;
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; if ((x2<0) || (x2>39)) color=0;
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; else if ((y2<0) || (y2>39)) color=0;
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; else color=scrn_page(x2,y2,PAGE2);
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; color_equals(color);
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; plot(xx,yy);
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; }
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; }
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; thetadiff+=(6.28/16.0);
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; page_flip();
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; usleep(100000);
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; }
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rts
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;=========================================================
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; gr_copy_current_to_offscreen 40x40
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;=========================================================
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; Copy draw page to $c00
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; Take image in 0xc00
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; Copy to DRAW_PAGE
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; Actually copy lines 0..39
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; Don't over-write bottom 4 lines of text
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gr_copy_current_to_offscreen_40x40:
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ldx #0
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gco_40x40_loop:
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lda gr_offsets,X
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sta OUTL
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sta INL
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lda gr_offsets+1,X
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clc
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adc DRAW_PAGE
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sta OUTH
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lda gr_offsets+1,X
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clc
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adc #$8
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sta INH
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ldy #39
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gco_40x40_inner:
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lda (OUTL),Y
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sta (INL),Y
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dey
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bpl gco_40x40_inner
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inx
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inx
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cpx #40
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bne gco_40x40_loop
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rts ; 6
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