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98 lines
2.2 KiB
C
98 lines
2.2 KiB
C
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//this example shows how to set up a palette and use 8x8 HW sprites
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//also shows how fast (or slow) C code is
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#include "neslib.h"
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#pragma data-name (push,"CHARS")
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#pragma data-name(pop)
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//#link "tileset1.c"
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// palette for balls, there are four sets for different ball colors
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extern unsigned char palSprites[16];
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// tile set, two planes for 4 colors
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extern unsigned char TILESET[8*256];
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//general purpose vars
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static unsigned char i,j;
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static unsigned char spr;
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//total number of balls on the screen
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//since there are 64 HW sprites, it is absolute max
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#define BALLS_MAX 64
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//balls parameters
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static unsigned char ball_x[BALLS_MAX];
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static unsigned char ball_y[BALLS_MAX];
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static unsigned char ball_dx[BALLS_MAX];
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static unsigned char ball_dy[BALLS_MAX];
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void main(void)
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{
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//copy tileset to RAM
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vram_adr(0x0);
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vram_write((unsigned char*)TILESET, sizeof(TILESET));
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pal_spr(palSprites);//set palette for sprites
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oam_size(1);
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ppu_on_all();//enable rendering
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//initialize balls parameters
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for(i=0;i<BALLS_MAX;++i)
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{
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//starting coordinates
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ball_x[i]=rand8();
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ball_y[i]=rand8();
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//direction bits
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j=rand8();
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//horizontal speed -3..-3, excluding 0
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spr=1+(rand8()%3);
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ball_dx[i]=j&1?-spr:spr;
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//vertical speed
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spr=1+(rand8()%3);
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ball_dy[i]=j&2?-spr:spr;
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}
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//now the main loop
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while(1)
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{
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ppu_wait_nmi();//wait for next TV frame
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spr=0;
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for(i=0;i<BALLS_MAX;++i)
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{
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//set a sprite for current ball
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spr=oam_spr(ball_x[i],ball_y[i],0x40,i&3,spr);//0x40 is tile number, i&3 is palette
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//move the ball
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ball_x[i]+=ball_dx[i];
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ball_y[i]+=ball_dy[i];
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//bounce the ball off the edges
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if(ball_x[i]>=(256-8)) ball_dx[i]=-ball_dx[i];
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if(ball_y[i]>=(240-8)) ball_dy[i]=-ball_dy[i];
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}
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}
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}
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