git.mutantstargoat.com Git - dosdemo/blob - src/plasma.c

   1 // Just a test with a run of the mill plasma
   2
   3 #include <stdlib.h>
   4 #include <math.h>
   5
   6 #include "demo.h"
   7 #include "screen.h"
   8 #include "tinyfps.h"
   9
  10 static int init(void);
  11 static void destroy(void);
  12 static void start(long trans_time);
  13 static void draw(void);
  14
  15 static struct screen scr = {
  16         "plasma",
  17         init,
  18         destroy,
  19         start,
  20         0,
  21         draw
  22 };
  23
  24 static unsigned long startingTime;
  25
  26 #define PSIN_SIZE 4096
  27 #define PPAL_SIZE 256
  28
  29 static unsigned char *psin1, *psin2, *psin3;
  30 static unsigned short *plasmaPal;
  31
  32 static unsigned short myBuffer[320 * 240];
  33
  34
  35 struct screen *plasma_screen(void)
  36 {
  37         return &scr;
  38 }
  39
  40 static int init(void)
  41 {
  42         int i;
  43
  44         initFpsFonts();
  45
  46         psin1 = (unsigned char*)malloc(sizeof(unsigned char) * PSIN_SIZE);
  47         psin2 = (unsigned char*)malloc(sizeof(unsigned char) * PSIN_SIZE);
  48         psin3 = (unsigned char*)malloc(sizeof(unsigned char) * PSIN_SIZE);
  49
  50         for (i = 0; i < PSIN_SIZE; i++)
  51         {
  52                 psin1[i] = (unsigned char)(sin((double)i / 45.0) * 63.0 + 63.0);
  53                 psin2[i] = (unsigned char)(sin((double)i / 75.0) * 42.0 + 42.0);
  54                 psin3[i] = (unsigned char)(sin((double)i / 32.0) * 88.0 + 88.0);
  55         }
  56
  57         plasmaPal = (unsigned short*)malloc(sizeof(unsigned short) * PPAL_SIZE);
  58         for (i=0; i<PPAL_SIZE; i++)
  59         {
  60                 int r, g, b;
  61                 int c = i;
  62                 if (c > 127) c = 255 - c;
  63                 c >>= 2;
  64                 g = 31 - c;
  65                 r = c;
  66                 b = g;
  67                 plasmaPal[i] = (r<<11) | (g<<5) | b;
  68         }
  69
  70         //return 0xCAFE;
  71         return 0;
  72 }
  73
  74 static void destroy(void)
  75 {
  76         free(psin1);
  77         free(psin2);
  78         free(psin3);
  79 }
  80
  81 static void start(long trans_time)
  82 {
  83         startingTime = time_msec;
  84 }
  85
  86 static void draw(void)
  87 {
  88         int x, y;
  89         unsigned char c;
  90         unsigned char s1, s2;
  91
  92         float dt = (float)(time_msec - startingTime) / 1000.0f;
  93         int t1 = sin(0.1f * dt) * 132 + 132;
  94         int t2 = sin(0.2f * dt) * 248 + 248;
  95         int t3 = sin(0.5f * dt) * 380 + 380;
  96
  97         unsigned int *vram32 = (unsigned int*)vmem_back;
  98         unsigned int p0, p1;
  99         for (y = 0; y < fb_height; y++)
 100         {
 101                 s1 = psin2[y + t2];
 102                 s2 = psin3[y + t1];
 103                 for (x = 0; x < fb_width; x+=2)
 104                 {
 105                         c = psin1[x + t1] + s1 + psin3[x + y + t3] + psin1[psin2[x + t2] + s2 + t3];
 106                         p0 = plasmaPal[c];
 107                         c = psin1[x + 1 + t1] + s1 + psin3[x + 1 + y + t3] + psin1[psin2[x + 1 + t2] + s2 + t3];
 108                         p1 = plasmaPal[c];
 109
 110                         *vram32++ = (p1 << 16) | p0;
 111                 }
 112         }
 113
 114         drawFps((unsigned short*)vmem_back);
 115
 116         swap_buffers(0);
 117 }