From aac303e17bf0a0429095a5168a1ecb77a89f4c41 Mon Sep 17 00:00:00 2001
From: Daniel Stenberg <daniel@haxx.se>
Date: Thu, 8 Jan 2004 13:03:04 +0000
Subject: Lee Pilgrim's patch to enable the chip8 plugin for the simulator I
 also code-policed it somewhat.

git-svn-id: svn://svn.rockbox.org/rockbox/trunk@4207 a1c6a512-1295-4272-9138-f99709370657
---
 apps/plugins/chip8.c | 454 ++++++++++++++++++++++++++-------------------------
 1 file changed, 232 insertions(+), 222 deletions(-)

(limited to 'apps/plugins/chip8.c')

diff --git a/apps/plugins/chip8.c b/apps/plugins/chip8.c
index 585295c405..d19e03d762 100644
--- a/apps/plugins/chip8.c
+++ b/apps/plugins/chip8.c
@@ -20,7 +20,6 @@
 #include "plugin.h"
 
 /* Only build for (correct) target */
-#ifndef SIMULATOR
 #ifdef HAVE_LCD_BITMAP 
 
 static struct plugin_api* rb; /* here is a global api struct pointer */
@@ -74,95 +73,100 @@ static void chip8_sound_off (void) { }
 
 static void op_call (word opcode)
 {
- chip8_regs.sp--;
- write_mem (chip8_regs.sp,chip8_regs.pc&0xff);
- chip8_regs.sp--;
- write_mem (chip8_regs.sp,chip8_regs.pc>>8);
- chip8_regs.pc=opcode;
+    chip8_regs.sp--;
+    write_mem (chip8_regs.sp,chip8_regs.pc&0xff);
+    chip8_regs.sp--;
+    write_mem (chip8_regs.sp,chip8_regs.pc>>8);
+    chip8_regs.pc=opcode;
 }
 
 static void op_jmp (word opcode)
 {
- chip8_regs.pc=opcode;
+    chip8_regs.pc=opcode;
 }
 
 static void op_key (word opcode)
 {
- byte key_value,cp_value;
- if ((opcode&0xff)==0x9e)
-  cp_value=1;
- else if ((opcode&0xff)==0xa1)
-  cp_value=0;
- else
-  return;
- key_value=chip8_keys[get_reg_value(opcode)&0x0f];
- if (cp_value==key_value) chip8_regs.pc+=2;
+    byte key_value,cp_value;
+    if ((opcode&0xff)==0x9e)
+        cp_value=1;
+    else if ((opcode&0xff)==0xa1)
+        cp_value=0;
+    else
+        return;
+    key_value=chip8_keys[get_reg_value(opcode)&0x0f];
+    if (cp_value==key_value)
+        chip8_regs.pc+=2;
 }
 
 static void op_skeq_const (word opcode)
 {
- if (get_reg_value(opcode)==(opcode&0xff)) chip8_regs.pc+=2;
+    if (get_reg_value(opcode)==(opcode&0xff))
+        chip8_regs.pc+=2;
 }
 
 static void op_skne_const (word opcode)
 {
- if (get_reg_value(opcode)!=(opcode&0xff)) chip8_regs.pc+=2;
+    if (get_reg_value(opcode)!=(opcode&0xff))
+        chip8_regs.pc+=2;
 }
 
 static void op_skeq_reg (word opcode)
 {
- if (get_reg_value(opcode)==get_reg_value_2(opcode)) chip8_regs.pc+=2;
+    if (get_reg_value(opcode)==get_reg_value_2(opcode))
+        chip8_regs.pc+=2;
 }
 
 static void op_skne_reg (word opcode)
 {
- if (get_reg_value(opcode)!=get_reg_value_2(opcode)) chip8_regs.pc+=2;
+    if (get_reg_value(opcode)!=get_reg_value_2(opcode))
+        chip8_regs.pc+=2;
 }
 
 static void op_mov_const (word opcode)
 {
- *get_reg_offset(opcode)=opcode&0xff;
+    *get_reg_offset(opcode)=opcode&0xff;
 }
 
 static void op_add_const (word opcode)
 {
- *get_reg_offset(opcode)+=opcode&0xff;
+    *get_reg_offset(opcode)+=opcode&0xff;
 }
 
 static void op_mvi (word opcode)
 {
- chip8_regs.i=opcode;
+    chip8_regs.i=opcode;
 }
 
 static void op_jmi (word opcode)
 {
- chip8_regs.pc=opcode+chip8_regs.alg[0];
+    chip8_regs.pc=opcode+chip8_regs.alg[0];
 }
 
 static void op_rand (word opcode)
 {
- *get_reg_offset(opcode)=rb->rand()&(opcode&0xff);
+    *get_reg_offset(opcode)=rb->rand()&(opcode&0xff);
 }
 
 static void math_or (byte *reg1,byte reg2)
 {
- *reg1|=reg2;
+    *reg1|=reg2;
 }
 
 static void math_mov (byte *reg1,byte reg2)
 {
- *reg1=reg2;
+    *reg1=reg2;
 }
 
 static void math_nop (byte *reg1,byte reg2)
 {
- (void)reg1;
- (void)reg2;
+    (void)reg1;
+    (void)reg2;
 }
 
 static void math_and (byte *reg1,byte reg2)
 {
- *reg1&=reg2;
+    *reg1&=reg2;
 }
 
 static void math_xor (byte *reg1,byte reg2)
@@ -172,168 +176,172 @@ static void math_xor (byte *reg1,byte reg2)
 
 static void math_add (byte *reg1,byte reg2)
 {
- word tmp;
- tmp=*reg1+reg2;
- *reg1=(byte)tmp;
- chip8_regs.alg[15]=tmp>>8;
+    word tmp;
+    tmp=*reg1+reg2;
+    *reg1=(byte)tmp;
+    chip8_regs.alg[15]=tmp>>8;
 }
 
 static void math_sub (byte *reg1,byte reg2)
 {
- word tmp;
- tmp=*reg1-reg2;
- *reg1=(byte)tmp;
- chip8_regs.alg[15]=((byte)(tmp>>8))+1;
+    word tmp;
+    tmp=*reg1-reg2;
+    *reg1=(byte)tmp;
+    chip8_regs.alg[15]=((byte)(tmp>>8))+1;
 }
 
 static void math_shr (byte *reg1,byte reg2)
 {
- (void)reg2;
- chip8_regs.alg[15]=*reg1&1;
- *reg1>>=1;
+    (void)reg2;
+    chip8_regs.alg[15]=*reg1&1;
+    *reg1>>=1;
 }
 
 static void math_shl (byte *reg1,byte reg2)
 {
- (void)reg2;
- chip8_regs.alg[15]=*reg1>>7;
- *reg1<<=1;
+    (void)reg2;
+    chip8_regs.alg[15]=*reg1>>7;
+    *reg1<<=1;
 }
 
 static void math_rsb (byte *reg1,byte reg2)
 {
- word tmp;
- tmp=reg2-*reg1;
- *reg1=(byte)tmp;
- chip8_regs.alg[15]=((byte)(tmp>>8))+1;
+    word tmp;
+    tmp=reg2-*reg1;
+    *reg1=(byte)tmp;
+    chip8_regs.alg[15]=((byte)(tmp>>8))+1;
 }
 
 static void op_system (word opcode)
 {
- switch ((byte)opcode)
- {
-  case 0xe0:
-   rb->memset (chip8_display,0,sizeof(chip8_display));
-   break;
-  case 0xee:
-   chip8_regs.pc=read_mem(chip8_regs.sp)<<8;
-   chip8_regs.sp++;
-   chip8_regs.pc+=read_mem(chip8_regs.sp);
-   chip8_regs.sp++;
-   break;
- }
+    switch ((byte)opcode)
+    {
+        case 0xe0:
+            rb->memset (chip8_display,0,sizeof(chip8_display));
+            break;
+        case 0xee:
+            chip8_regs.pc=read_mem(chip8_regs.sp)<<8;
+            chip8_regs.sp++;
+            chip8_regs.pc+=read_mem(chip8_regs.sp);
+            chip8_regs.sp++;
+            break;
+    }
 }
 
 static void op_misc (word opcode)
 {
- byte *reg,i,j;
- reg=get_reg_offset(opcode);
- switch ((byte)opcode)
- {
-  case 0x07:
-   *reg=chip8_regs.delay;
-   break;
-  case 0x0a:
-   if (chip8_key_pressed)
-    *reg=chip8_key_pressed-1;
-   else
-    chip8_regs.pc-=2;
-   break;
-  case 0x15:
-   chip8_regs.delay=*reg;
-   break;
-  case 0x18:
-   chip8_regs.sound=*reg;
-   if (chip8_regs.sound) chip8_sound_on();
-   break;
-  case 0x1e:
-   chip8_regs.i+=(*reg);
-   break;
-  case 0x29:
-   chip8_regs.i=((word)(*reg&0x0f))*5;
-   break;
-  case 0x33:
-   i=*reg;
-   for (j=0;i>=100;i-=100) j++;
-   write_mem (chip8_regs.i,j);
-   for (j=0;i>=10;i-=10) j++;
-   write_mem (chip8_regs.i+1,j);
-   write_mem (chip8_regs.i+2,i);
-   break;
-  case 0x55:
-   for (i=0,j=(opcode>>8)&0x0f;i<=j;++i)
-    write_mem(chip8_regs.i+i,chip8_regs.alg[i]);
-   break;
-  case 0x65:
-   for (i=0,j=(opcode>>8)&0x0f;i<=j;++i)
-    chip8_regs.alg[i]=read_mem(chip8_regs.i+i);
-   break;
- }
+    byte *reg,i,j;
+    reg=get_reg_offset(opcode);
+    switch ((byte)opcode)
+    {
+        case 0x07:
+            *reg=chip8_regs.delay;
+            break;
+        case 0x0a:
+            if (chip8_key_pressed)
+                *reg=chip8_key_pressed-1;
+            else
+                chip8_regs.pc-=2;
+            break;
+        case 0x15:
+            chip8_regs.delay=*reg;
+            break;
+        case 0x18:
+            chip8_regs.sound=*reg;
+            if (chip8_regs.sound)
+                chip8_sound_on();
+            break;
+        case 0x1e:
+            chip8_regs.i+=(*reg);
+            break;
+        case 0x29:
+            chip8_regs.i=((word)(*reg&0x0f))*5;
+            break;
+        case 0x33:
+            i=*reg;
+            for (j=0;i>=100;i-=100)
+                j++;
+            write_mem (chip8_regs.i,j);
+            for (j=0;i>=10;i-=10)
+                j++;
+            write_mem (chip8_regs.i+1,j);
+            write_mem (chip8_regs.i+2,i);
+            break;
+        case 0x55:
+            for (i=0,j=(opcode>>8)&0x0f; i<=j; ++i)
+                write_mem(chip8_regs.i+i,chip8_regs.alg[i]);
+            break;
+        case 0x65:
+            for (i=0,j=(opcode>>8)&0x0f; i<=j; ++i)
+                chip8_regs.alg[i]=read_mem(chip8_regs.i+i);
+            break;
+    }
 }
 
 static void op_sprite (word opcode)
 {
- byte *q;
- byte n,x,x2,y,collision;
- word p;
- x=get_reg_value(opcode)&63;
- y=get_reg_value_2(opcode)&31;
- p=chip8_regs.i;
- q=chip8_display+y*64;
- n=opcode&0x0f;
- if (n+y>32) n=32-y;
- for (collision=1;n;--n,q+=64)
- {
-  for (y=read_mem(p++),x2=x;y;y<<=1,x2=(x2+1)&63)
-   if (y&0x80) collision&=(q[x2]^=0xff);
- }
- chip8_regs.alg[15]=collision^1;
+    byte *q;
+    byte n,x,x2,y,collision;
+    word p;
+    x=get_reg_value(opcode)&63;
+    y=get_reg_value_2(opcode)&31;
+    p=chip8_regs.i;
+    q=chip8_display+y*64;
+    n=opcode&0x0f;
+    if (n+y>32)
+        n=32-y;
+    for (collision=1;n;--n,q+=64)
+    {
+        for (y=read_mem(p++),x2=x;y;y<<=1,x2=(x2+1)&63)
+            if (y&0x80) collision&=(q[x2]^=0xff);
+    }
+    chip8_regs.alg[15]=collision^1;
 }
 
 static math_fn math_opcodes[16]=
 {
- math_mov,
- math_or,
- math_and,
- math_xor,
- math_add,
- math_sub,
- math_shr,
- math_rsb,
- math_nop,
- math_nop,
- math_nop,
- math_nop,
- math_nop,
- math_nop,
- math_shl,
- math_nop
+    math_mov,
+    math_or,
+    math_and,
+    math_xor,
+    math_add,
+    math_sub,
+    math_shr,
+    math_rsb,
+    math_nop,
+    math_nop,
+    math_nop,
+    math_nop,
+    math_nop,
+    math_nop,
+    math_shl,
+    math_nop
 };
 
 static void op_math (word opcode)
 {
- (*(math_opcodes[opcode&0x0f]))
+    (*(math_opcodes[opcode&0x0f]))
         (get_reg_offset(opcode),get_reg_value_2(opcode));
 }
 
 static opcode_fn main_opcodes[16]=
 {
- op_system,
- op_jmp,
- op_call,
- op_skeq_const,
- op_skne_const,
- op_skeq_reg,
- op_mov_const,
- op_add_const,
- op_math,
- op_skne_reg,
- op_mvi,
- op_jmi,
- op_rand,
- op_sprite,
- op_key,
- op_misc
+    op_system,
+    op_jmp,
+    op_call,
+    op_skeq_const,
+    op_skne_const,
+    op_skeq_reg,
+    op_mov_const,
+    op_add_const,
+    op_math,
+    op_skne_reg,
+    op_mvi,
+    op_jmi,
+    op_rand,
+    op_sprite,
+    op_key,
+    op_misc
 };
 
 /****************************************************************************/
@@ -341,37 +349,36 @@ static opcode_fn main_opcodes[16]=
 /****************************************************************************/
 static void chip8_update_display(void)
 {
- int x,y,i;
- byte w;
- byte* row;
+    int x,y,i;
+    byte w;
+    byte* row;
 
- for (y=0;y<=7;++y)                             /* 32 rows                  */
- {
-  row = lcd_framebuf[y];
-  for (x=0;x<64;++x)                            /* 64 columns               */
-  {
-    w = 0;
-    for (i=0;i<=3;i++)
+    for (y=0;y<=7;++y)                          /* 32 rows                  */
     {
-      w = w >> 2;
-      if (chip8_display[x+(y*4+i)*64] != 0)
-      {
-        w += 128+64;
-      }
+        row = lcd_framebuf[y];
+        for (x=0;x<64;++x)                      /* 64 columns               */
+        {
+            w = 0;
+            for (i=0;i<=3;i++)
+            {
+                w = w >> 2;
+                if (chip8_display[x+(y*4+i)*64] != 0)
+                {
+                    w += 128+64;
+                }
+            }
+            *row++ = w;
+        }
     }
-    *row++ = w;
-  }
- }
- rb->lcd_blit(lcd_framebuf[0], 24, 0, 64, 8, 64);
+    rb->lcd_blit(lcd_framebuf[0], 24, 0, 64, 8, 64);
 }
 
-
 static void chip8_keyboard(void)
 {
   switch (rb->button_get(false))
   {
     case BUTTON_OFF:                                      /* Abort Emulator */
-      chip8_running = false;
+        chip8_running = false;
       break;
 
     case BUTTON_UP:                 chip8_keys[2] = 1; break;
@@ -408,30 +415,34 @@ static void chip8_keyboard(void)
 /****************************************************************************/
 static void chip8_execute(void)
 {
-  byte i;
-  byte key_pressed=0;
-  word opcode;
-  for (i = chip8_iperiod ; i ;--i)
-  {                                                     /* Fetch the opcode */
-    opcode=(read_mem(chip8_regs.pc)<<8)+read_mem(chip8_regs.pc+1);
+    byte i;
+    byte key_pressed=0;
+    word opcode;
+    for (i = chip8_iperiod ; i ;--i)
+    {                                                 /* Fetch the opcode */
+        opcode=(read_mem(chip8_regs.pc)<<8)+read_mem(chip8_regs.pc+1);
 
-    chip8_regs.pc+=2;
-    (*(main_opcodes[opcode>>12]))(opcode&0x0fff);    /* Emulate this opcode */
-  }
-                                                           /* Update timers */
-  if (chip8_regs.delay) --chip8_regs.delay;
-  if (chip8_regs.sound) --chip8_regs.sound; /* How could we make sound on the archos? */
+        chip8_regs.pc+=2;
+        (*(main_opcodes[opcode>>12]))(opcode&0x0fff); /* Emulate this opcode */
+    }
+                                                      /* Update timers */
+    if (chip8_regs.delay)
+        --chip8_regs.delay;
+
+    if (chip8_regs.sound)
+        --chip8_regs.sound;       /* How could we make sound on the archos? */
                                                /* Update the machine status */
-  chip8_update_display();
-  chip8_keyboard();
-  rb->yield();  /* we should regulate the speed by timer query, sleep/yield */
-
-  for (i=key_pressed=0;i<16;++i)                /* check if a key was first */
-    if (chip8_keys[i]) key_pressed=i+1;         /* pressed                  */
-  if (key_pressed && key_pressed!=chip8_key_pressed)
-    chip8_key_pressed=key_pressed;
-  else
-    chip8_key_pressed=0;
+    chip8_update_display();
+    chip8_keyboard();
+    rb->yield(); /* we should regulate the speed by timer query, sleep/yield */
+
+    for (i=key_pressed=0;i<16;++i)              /* check if a key was first */
+        if (chip8_keys[i])
+            key_pressed=i+1;         /* pressed                  */
+    if (key_pressed && key_pressed!=chip8_key_pressed)
+        chip8_key_pressed=key_pressed;
+    else
+        chip8_key_pressed=0;
 }
 
 /****************************************************************************/
@@ -439,32 +450,32 @@ static void chip8_execute(void)
 /****************************************************************************/
 static void chip8_reset(void)
 {
- static byte chip8_sprites[16*5]=
- {
-  0xf9,0x99,0xf2,0x62,0x27,
-  0xf1,0xf8,0xff,0x1f,0x1f,
-  0x99,0xf1,0x1f,0x8f,0x1f,
-  0xf8,0xf9,0xff,0x12,0x44,
-  0xf9,0xf9,0xff,0x9f,0x1f,
-  0xf9,0xf9,0x9e,0x9e,0x9e,
-  0xf8,0x88,0xfe,0x99,0x9e,
-  0xf8,0xf8,0xff,0x8f,0x88,
- };
- byte i;
- for (i=0;i<16*5;++i)
- {
-  write_mem (i<<1,chip8_sprites[i]&0xf0);
-  write_mem ((i<<1)+1,chip8_sprites[i]<<4);
- }
- rb->memset (chip8_regs.alg,0,sizeof(chip8_regs.alg));
- rb->memset (chip8_keys,0,sizeof(chip8_keys));
- chip8_key_pressed=0;
- rb->memset (chip8_display,0,sizeof(chip8_display));
- chip8_regs.delay=chip8_regs.sound=chip8_regs.i=0;
- chip8_regs.sp=0x1e0;
- chip8_regs.pc=0x200;
- chip8_sound_off ();
- chip8_running=1;
+    static byte chip8_sprites[16*5]=
+     {
+         0xf9,0x99,0xf2,0x62,0x27,
+         0xf1,0xf8,0xff,0x1f,0x1f,
+         0x99,0xf1,0x1f,0x8f,0x1f,
+         0xf8,0xf9,0xff,0x12,0x44,
+         0xf9,0xf9,0xff,0x9f,0x1f,
+         0xf9,0xf9,0x9e,0x9e,0x9e,
+         0xf8,0x88,0xfe,0x99,0x9e,
+         0xf8,0xf8,0xff,0x8f,0x88,
+     };
+    byte i;
+    for (i=0;i<16*5;++i)
+    {
+        write_mem (i<<1,chip8_sprites[i]&0xf0);
+        write_mem ((i<<1)+1,chip8_sprites[i]<<4);
+    }
+    rb->memset (chip8_regs.alg,0,sizeof(chip8_regs.alg));
+    rb->memset (chip8_keys,0,sizeof(chip8_keys));
+    chip8_key_pressed=0;
+    rb->memset (chip8_display,0,sizeof(chip8_display));
+    chip8_regs.delay=chip8_regs.sound=chip8_regs.i=0;
+    chip8_regs.sp=0x1e0;
+    chip8_regs.pc=0x200;
+    chip8_sound_off ();
+    chip8_running=1;
 }
 
 static bool chip8_init(char* file)
@@ -541,5 +552,4 @@ enum plugin_status plugin_start(struct plugin_api* api, void* parameter)
     return chip8_run(filename) ? PLUGIN_OK : PLUGIN_ERROR;
 }
 
-#endif // #ifdef HAVE_LCD_BITMAP 
-#endif // #ifndef SIMULATOR
+#endif /* #ifdef HAVE_LCD_BITMAP */
-- 
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