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8bitworkshop/presets/atari7800/example_small_sprites.c78
Steven Hugg d9001df5d4 cc7800
2023-11-28 18:08:02 -06:00

60 lines
2.2 KiB
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// example from https://github.com/steux/cc7800 - license: GPLv3
#include "prosystem.h"
#include "multisprite.h"
char i, xpos, ypos;
#define NB_SMALL_SPRITES 128
ramchip short sp_xpos[NB_SMALL_SPRITES], sp_ypos[NB_SMALL_SPRITES];
ramchip char sp_direction[NB_SMALL_SPRITES];
const signed short dx[24] = {300, 289, 259, 212, 149, 77, 0, -77, -150, -212, -259, -289, -300, -289, -259, -212, -149, -77, 0, 77, 149, 212, 259, 289};
const signed short dy[24] = {0, 124, 240, 339, 415, 463, 480, 463, 415, 339, 240, 124, 0, -124, -239, -339, -415, -463, -480, -463, -415, -339, -240, -124};
const char horizontal_pingpong[24] = { 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, 1, 0, 23, 22, 21, 20, 19, 18, 17, 16, 15, 14, 13 };
const char vertical_pingpong[24] = { 0, 23, 22, 21, 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, 1 };
// Generated with sprites7800 missile.yaml
holeydma reversed scattered(16,1) char missile[16] = {
0x18, 0x96, 0x7a, 0x7e, 0x7e, 0x6e, 0x9a, 0x28, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00
};
void main()
{
multisprite_init();
*P0C1 = multisprite_color(0x1c); // Yellow
*P0C2 = multisprite_color(0x37); // Orange
*P0C3 = multisprite_color(0x43); // Red
// Initialize small sprites
for (ypos = 0, xpos = 0, i = 0, X = 0; X != NB_SMALL_SPRITES; xpos++, ypos++, X++) {
sp_xpos[X] = xpos << 8;
sp_ypos[X] = ypos << 8;
sp_direction[X] = i++;
if (i == 24) i = 0;
}
// Main loop
do {
multisprite_flip();
for (i = 0; i != NB_SMALL_SPRITES; i++) {
X = i;
Y = sp_direction[X];
sp_xpos[X] += dx[Y];
sp_ypos[X] += dy[Y];
xpos = sp_xpos[X] >> 8;
ypos = sp_ypos[X] >> 8;
if ((xpos < 5 && (dx[Y] >> 8) < 0) ||
(xpos >= 150 && (dx[Y] >> 8) >= 0)) {
sp_direction[X] = horizontal_pingpong[Y];
}
if ((ypos < 5 && (dy[Y] >> 8) < 0) ||
(ypos >= MS_YMAX - 20 && (dy[Y] >> 8) >= 0)) {
sp_direction[X] = vertical_pingpong[Y];
}
multisprite_display_small_sprite(xpos, ypos, missile, 1, 0, 8);
}
} while(1);
}