Add missile command sample game

include/gfx/mcbitmap.c

@@ -34,9 +34,10 @@ char MixedColors[4][4][8] = {
 
 void bmmc_put(const Bitmap * bm, int x, int y, char c)
 {
-	char * dp = bm->data + bm->cwidth * (y & ~7) + ((x & ~7) | (y & 7));
+	char	*	dp = bm->data + bm->cwidth * (y & ~7) + ((x & ~7) | (y & 7));
+	char		pat = cbytes[c & 3];
 
-	*dp = (*dp & andmask[x & 7]) | (cbytes[c & 3] & ormask[x & 7]);
+	*dp = ((*dp ^ pat) & andmask[x & 7]) ^ pat;
 }
 
 char bmmc_get(const Bitmap * bm, int x, int y)

oscar64/NativeCodeGenerator.cpp

@@ -11987,7 +11987,7 @@ void NativeCodeBasicBlock::BlockSizeReduction(void)
 				i += 3;
 			}
 			else if (i + 5 < mIns.Size() &&
-				mIns[i + 0].mType == ASMIT_LDA &&
+				mIns[i + 0].ChangesAccuAndFlag() &&
 				mIns[i + 1].mType == ASMIT_CMP && mIns[i + 1].mMode == ASMIM_IMMEDIATE && mIns[i + 1].mAddress == 0x01 &&
 				mIns[i + 2].mType == ASMIT_LDA && mIns[i + 2].mMode == ASMIM_IMMEDIATE && mIns[i + 2].mAddress == 0x00 &&
 				mIns[i + 3].mType == ASMIT_ADC && mIns[i + 3].mMode == ASMIM_IMMEDIATE && mIns[i + 3].mAddress == 0xff &&
@@ -13032,7 +13032,8 @@ bool NativeCodeBasicBlock::PeepHoleOptimizer(int pass)
 								}
 								else
 									mIns.Insert(i + 0, NativeCodeInstruction(ASMIT_LDY, ASMIM_ZERO_PAGE, iins->mAddress));
-								mIns[i + 0].mLive = mIns[i - 1].mLive | LIVE_CPU_REG_Y | LIVE_MEM;
+								if (i > 0)
+									mIns[i + 0].mLive = mIns[i - 1].mLive | LIVE_CPU_REG_Y | LIVE_MEM;
 							}
 
 							progress = true;
@@ -13994,6 +13995,16 @@ bool NativeCodeBasicBlock::PeepHoleOptimizer(int pass)
 #endif
 
 #endif
+					else if (
+						mIns[i + 0].mType == ASMIT_ASL && mIns[i + 0].mMode == ASMIM_ZERO_PAGE &&
+						mIns[i + 1].mType == ASMIT_ROL && mIns[i + 1].mMode == ASMIM_ZERO_PAGE && mIns[i + 1].mAddress != mIns[i + 0].mAddress &&
+						mIns[i + 2].mType == ASMIT_LDA && mIns[i + 2].mMode == ASMIM_ZERO_PAGE && mIns[i + 2].mAddress == mIns[i + 0].mAddress && !(mIns[i + 2].mLive & (LIVE_MEM | LIVE_CPU_REG_C | LIVE_CPU_REG_Z)))
+					{
+						mIns[i + 0].mType = ASMIT_LDA; mIns[i + 0].mLive |= LIVE_CPU_REG_A;
+						mIns[i + 2].mType = ASMIT_ROL; mIns[i + 2].mAddress = mIns[i + 1].mAddress; mIns[i + 2].mLive |= LIVE_MEM;
+						mIns[i + 1].mType = ASMIT_ASL; mIns[i + 1].mMode = ASMIM_IMPLIED; mIns[i + 1].mLive |= LIVE_CPU_REG_A | LIVE_CPU_REG_C;
+						progress = true;
+					}
 #if 1
 					else if (
 						mIns[i + 0].mType == ASMIT_ASL && mIns[i + 0].mMode == ASMIM_ZERO_PAGE &&
@@ -14230,6 +14241,36 @@ bool NativeCodeBasicBlock::PeepHoleOptimizer(int pass)
 						progress = true;
 					}
 #endif
+#if 1
+					else if (
+						mIns[i + 0].mType == ASMIT_LDA && 
+						mIns[i + 1].mType == ASMIT_STA && mIns[i + 1].mMode == ASMIM_ZERO_PAGE && !mIns[i + 0].MayBeChangedOnAddress(mIns[i + 1]) &&
+						mIns[i + 2].mType == ASMIT_LDA && mIns[i + 2].mMode == ASMIM_ZERO_PAGE &&
+						mIns[i + 3].mType == ASMIT_ORA && mIns[i + 3].SameEffectiveAddress(mIns[i + 0]))
+					{
+						mIns[i + 2].mType = ASMIT_ORA;
+						mIns[i + 3].mType = ASMIT_NOP; mIns[i + 3].mMode = ASMIM_IMPLIED;
+
+						progress = true;
+					}
+#endif
+#if 1
+					else if (
+						mIns[i + 0].mType == ASMIT_LDA && 
+						mIns[i + 1].mType == ASMIT_EOR && mIns[i + 1].mMode == ASMIM_IMMEDIATE && mIns[i + 1].mAddress == 0xff &&
+						mIns[i + 2].mType == ASMIT_SEC &&
+						mIns[i + 3].mType == ASMIT_ADC)
+					{
+						mIns.Insert(i + 4, mIns[i + 0]);
+
+						mIns[i + 0].mType = ASMIT_NOP; mIns[i + 0].mMode = ASMIM_IMPLIED;
+						mIns[i + 1].mType = ASMIT_NOP; mIns[i + 1].mMode = ASMIM_IMPLIED;
+						mIns[i + 3].mType = ASMIT_LDA; mIns[i + 3].mLive |= LIVE_CPU_REG_C;
+						mIns[i + 4].mType = ASMIT_SBC;
+
+						progress = true;
+					}
+#endif
 #if 1
 					else if (
 						mIns[i + 0].mType == ASMIT_STA && mIns[i + 0].mMode == ASMIM_ZERO_PAGE &&

oscar64/oscar64.cpp

@@ -73,7 +73,7 @@ int main(int argc, const char** argv)
 
 #else
 		strcpy(strProductName, "oscar64");
-		strcpy(strProductVersion, "1.3.74");
+		strcpy(strProductVersion, "1.4.75");
 
 #ifdef __APPLE__
 		uint32_t length = sizeof(basePath);

oscar64/oscar64.rc

@@ -25,8 +25,8 @@ LANGUAGE LANG_ENGLISH, SUBLANG_NEUTRAL
 //
 
 VS_VERSION_INFO VERSIONINFO
- FILEVERSION 1,3,74,0
+ FILEVERSION 1,4,75,0
- PRODUCTVERSION 1,3,74,0
+ PRODUCTVERSION 1,4,75,0
  FILEFLAGSMASK 0x3fL
 #ifdef _DEBUG
  FILEFLAGS 0x1L
@@ -43,12 +43,12 @@ BEGIN
         BEGIN
             VALUE "CompanyName", "oscar64"
             VALUE "FileDescription", "oscar64 compiler"
-            VALUE "FileVersion", "1.3.74.0"
+            VALUE "FileVersion", "1.4.75.0"
             VALUE "InternalName", "oscar64.exe"
             VALUE "LegalCopyright", "Copyright (C) 2021"
             VALUE "OriginalFilename", "oscar64.exe"
             VALUE "ProductName", "oscar64"
-            VALUE "ProductVersion", "1.3.74.0"
+            VALUE "ProductVersion", "1.4.75.0"
         END
     END
     BLOCK "VarFileInfo"

oscar64setup/oscar64setup.vdproj

@@ -94,6 +94,12 @@
         }
         "Entry"
         {
+        "MsmKey" = "8:_1ED10FB93DDA4801BF72003E21B2CE55"
+        "OwnerKey" = "8:_UNDEFINED"
+        "MsmSig" = "8:_UNDEFINED"
+        }
+        "Entry"
+        {
         "MsmKey" = "8:_1F88FA4F35F043B3ABFCB552FCEA5CDD"
         "OwnerKey" = "8:_UNDEFINED"
         "MsmSig" = "8:_UNDEFINED"
@@ -1087,6 +1093,26 @@
             "IsDependency" = "11:FALSE"
             "IsolateTo" = "8:"
             }
+            "{1FB2D0AE-D3B9-43D4-B9DD-F88EC61E35DE}:_1ED10FB93DDA4801BF72003E21B2CE55"
+            {
+            "SourcePath" = "8:..\\samples\\games\\missile.c"
+            "TargetName" = "8:missile.c"
+            "Tag" = "8:"
+            "Folder" = "8:_BC04C0DDE264410096618981E4E890DA"
+            "Condition" = "8:"
+            "Transitive" = "11:FALSE"
+            "Vital" = "11:TRUE"
+            "ReadOnly" = "11:FALSE"
+            "Hidden" = "11:FALSE"
+            "System" = "11:FALSE"
+            "Permanent" = "11:FALSE"
+            "SharedLegacy" = "11:FALSE"
+            "PackageAs" = "3:1"
+            "Register" = "3:1"
+            "Exclude" = "11:FALSE"
+            "IsDependency" = "11:FALSE"
+            "IsolateTo" = "8:"
+            }
             "{1FB2D0AE-D3B9-43D4-B9DD-F88EC61E35DE}:_1F88FA4F35F043B3ABFCB552FCEA5CDD"
             {
             "SourcePath" = "8:..\\include\\c64\\rasterirq.c"
@@ -3492,15 +3518,15 @@
         {
         "Name" = "8:Microsoft Visual Studio"
         "ProductName" = "8:oscar64"
-        "ProductCode" = "8:{109FC925-4A6D-4868-A60D-42BF3DFE541B}"
+        "ProductCode" = "8:{1FF1624F-A9FD-402D-806B-6CE9925FB690}"
-        "PackageCode" = "8:{C6215A39-7DD0-4667-93FB-46373135B9C8}"
+        "PackageCode" = "8:{47F7AA54-A5D7-4A82-8276-0DCD0FE332D4}"
         "UpgradeCode" = "8:{9AB61EFF-ACAC-4079-9950-8D96615CD4EF}"
         "AspNetVersion" = "8:2.0.50727.0"
         "RestartWWWService" = "11:FALSE"
         "RemovePreviousVersions" = "11:TRUE"
         "DetectNewerInstalledVersion" = "11:TRUE"
         "InstallAllUsers" = "11:FALSE"
-        "ProductVersion" = "8:1.3.74"
+        "ProductVersion" = "8:1.4.75"
         "Manufacturer" = "8:oscar64"
         "ARPHELPTELEPHONE" = "8:"
         "ARPHELPLINK" = "8:"

samples/games/build.sh

@@ -2,4 +2,5 @@
 ../../bin/oscar64 snake.c
 ../../bin/oscar64 lander.c -n
 ../../bin/oscar64 maze3d.c -n
+../../bin/oscar64 missile.c -O3 -n
 

samples/games/lander.c

@@ -223,15 +223,15 @@ void game_loop(void)
 	case GS_PLAYING:
 	{
 		// Check player input on every frame
-		joy_poll(1);
+		joy_poll(0);
-		lander_move(&TheGame.lander, joyx[1], joyy[1]);
+		lander_move(&TheGame.lander, joyx[0], joyy[0]);
 		LanderCollision col = lander_check(&TheGame.lander);
 		if (col == LCOL_GROUND)
 			game_state(GS_COLLIDE);
 		else if (col == LCOL_PAD)
 			game_state(GS_LANDED);
 		else
-			lander_show(&TheGame.lander, joyx[1], joyy[1]);
+			lander_show(&TheGame.lander, joyx[0], joyy[0]);
 	}	break;
 	case GS_LANDED:
 		if (!--TheGame.count)

samples/games/make.bat

@@ -1,4 +1,4 @@
 call ..\..\bin\oscar64 snake.c
 call ..\..\bin\oscar64 -n lander.c
 call ..\..\bin\oscar64 -n maze3d.c
-call ..\..\bin\oscar64 -n missile.c
+call ..\..\bin\oscar64 -n -O3 missile.c

samples/games/maze3d.c

@@ -419,19 +419,19 @@ int main(void)
 	for(;;)
 	{
 		// Read joystick input
-		joy_poll(1);
+		joy_poll(0);
 
 		// Forward or backward motion
-		if (joyy[1])
+		if (joyy[0])
 		{
 			// Target square
-			sbyte tx = px - dx * joyy[1];
+			sbyte tx = px - dx * joyy[0];
-			sbyte ty = py - dy * joyy[1];
+			sbyte ty = py - dy * joyy[0];
 
 			// Check i empty
 			if (maze[ty][tx] != '#')
 			{
-				if (joyy[1] < 0)
+				if (joyy[0] < 0)
 				{
 					// Forward animation
 					px = tx;
@@ -457,7 +457,7 @@ int main(void)
 		// Check if new rotation
 		if (!rotate)
 		{
-			if (joyx[1] == 1)
+			if (joyx[0] == 1)
 			{
 				// Rotate right
 				sbyte	t = dx; dx = -dy; dy = t;
@@ -465,7 +465,7 @@ int main(void)
 				maze_draw(zxdist0);
 				screen_left();
 			}
-			else if (joyx[1] == -1)
+			else if (joyx[0] == -1)
 			{
 				// Rotate left
 				sbyte	t = dx; dx = dy; dy = -t;
@@ -474,7 +474,7 @@ int main(void)
 				screen_right();
 			}
 		}
-		else if (!joyx[1])
+		else if (!joyx[0])
 		{
 			// No rotation, may rotate again in next frame
 			rotate = false;

samples/games/missile.c

@@ -3,114 +3,295 @@
 #include <c64/sprites.h>
 #include <c64/joystick.h>
 #include <c64/rasterirq.h>
+#include <c64/cia.h>
 #include <gfx/mcbitmap.h>
 #include <string.h>
 #include <stdlib.h>
 
+// Make some room
 #pragma region(main, 0x0a00, 0xc800, , , {code, data, bss, heap, stack} )
 
+// Sprite assets
 const char MissileSprites[] = {
 #embed "../resources/missilesprites.bin"	
 };
 
+// Charset assets
 const char MissileChars[] = {
 #embed "../resources/missilechars.bin"	
 };
 
+// Graphics areas in bank 3
 #define Color1	((char *)0xc800)
 #define Color2	((char *)0xd800)
 #define Hires	((char *)0xe000)
 #define Sprites	((char *)0xd000)
 #define Charset ((char *)0xd800)
 
+// Joystick and crosshair control
 int		CrossX = 160, CrossY = 100;
 bool	CrossP = false;
 char	CrossDelay = 0;
 
+// Display bitmap
 Bitmap			sbm;
 const ClipRect	scr = { 0, 0, 320, 200 };
 
+// Structure for a explosion
 struct Explosion
 {
-	int				x, y;
+	int				x, y;	// Center of circle
-	char			r;
+	char			r;		// Radius of circle
-	Explosion	*	next;
+	Explosion	*	next;	// Next explosion in list
 };
 
+// Structure for a missile (defensive and ICBM)
 struct Missile
 {
-	int				sx, sy, tx, ty, x, y, dx, dy;
+	int				sx, sy;	// start position
-	int				d;
+	int				tx, ty;	// target position
-	char			cnt;
+	int				x, y;	// current position
-	Missile		*	next;
+	int				dx, dy;	// distance in x and y
+	int				d;		// error term for Bresenham
+	sbyte			stepx;	// direction in x (+1 or -1)
+	sbyte			cnt;	// speed counter
+	Missile		*	next;	// next missile in list
 };
 
+// Storage space for explosion
 Explosion		explosions[16];
+// First free and first used explosion
 Explosion	*	efree, * eused;	
 
+// Storage space for defending missiles
 Missile			missiles[8];
+// First free and first used missile
 Missile		*	mfree, * mused;
+// Number of missiles available
+char			nmissiles;
 
+// Storage space for ICMBs
 Missile			icbms[16];
+// First free and first used ICBM
 Missile		*	ifree, * iused;
+// Speed and number of ICBMs still incomming
+char			icbmspeed, icbmcount;
 
-bool cities[6];
+// Cities not yet destroyed
+bool 			cities[6];
+char			ncities;
 
+// Init status bar at top
+void status_init(void)
+{
+	memset(Color1, ' ', 40);
+	memset(Color2, 1, 40);
 
+	for(char i=0; i<8; i++)	
+	{
+		Color1[i +  2] = '0';
+		Color1[i + 12] = '0';
+		Color2[i + 12] = 7;
+	}
+}
+
+// Expand an 8x8 charactor to 16x16 on screen
+void char_put(char cx, char cy, char c, char color)
+{
+	// Get pointer to glyph data
+	const char	*	sp = MissileChars + 8 * c;
+
+	// Loop over all pixel
+	for(char y=0; y<8; y++)
+	{
+		char cl = sp[y];
+		for(char x=0; x<8; x++)
+		{
+			// Draw two pixel if bit is set
+			if (cl & 128)
+			{
+				bmmc_put(&sbm, cx + 2 * x, cy + 2 * y + 0, color);
+				bmmc_put(&sbm, cx + 2 * x, cy + 2 * y + 1, color);
+			}
+
+			// Next bit
+			cl <<= 1;
+		}
+	}
+}
+
+// Write a zero terminated string on screen
+void char_write(char cx, char cy, const char * s, char color)
+{
+	// Loop over all characters
+	while (*s)
+	{
+		char_put(cx, cy, *s, color);
+		s++;
+		cx += 16;
+	}
+}
+
+// Increment the score from a given digit on
+void score_inc(char digit, unsigned val)
+{
+	// Lowest digit to increment
+	char	at = 9 - digit;
+
+	// Loop while there is still score to account for
+	while (val)
+	{
+		// Increment one character
+		char	ch = Color1[at] + val % 10;
+
+		// Remove low digit from number
+		val /= 10;
+
+		// Check overflow
+		if (ch > '9')
+		{
+			ch -= 10;
+			val++;
+		}
+
+		Color1[at] = ch;
+
+		// Next higher character
+		at --;
+	}
+}
+
+// Reset score and update high score
+void score_reset(void)
+{
+	// Find first digit, where score and highscore differ
+	char i = 0;
+	while (i < 8 && Color1[i + 2] == Color1[i + 12])
+		i++;
+
+	// Check if new score is higher
+	if (i < 8 && Color1[i + 2] > Color1[i + 12])
+	{
+		// If so, copy to highscore
+		while (i < 8)
+		{
+			Color1[i + 12] = Color1[i + 2];
+			i++;
+		}
+	}
+
+	// Clear score
+	for(char i=0; i<8; i++)	
+		Color1[i + 2] = '0';	
+}
+
+// Update number of missiles
+void status_missiles(char num)
+{
+	char	n = 0;
+
+	// Draw full pairs
+	while (2 * n + 1 < num)
+	{
+		Color1[25 + n] = 92;
+		n++;
+	}
+	// Draw remaining single one
+	if (num & 1)
+	{
+		Color1[25 + n] = 93;
+		n++;
+	}
+	// Empty remainder
+	while (n < 15)
+	{
+		Color1[25 + n] = 94;
+		n++;
+	}
+}
+
+// Initialize explosion list
 void explosion_init(void)
 {
+	// No explosion active
 	eused = nullptr;
+
+	// First free explosion element
 	efree = explosions;
+	// Build list
 	for(char i=0; i<15; i++)
 		explosions[i].next = explosions + i + 1;
+	// Terminate last element
 	explosions[15].next = nullptr;
 }
 
+// Start a new explosion
 void explosion_start(int x, int y)
 {
+	// Free slot in list of explosions?
 	if (efree)
 	{
+		// Move entry from free to used list
 		Explosion	*	e = efree;
 		efree = e->next;
 		e->next = eused;
 		eused = e;
 
+		// Initialize position and size
 		e->r = 0;
 		e->x = x;
 		e->y = y;
 	}
 }
 
+// Animate all explosions
 void explosion_animate(void)
 {
+	// Loop over active explosions with "e", use "ep" to point
+	// to previous explosion, so we can remove the current explosion
+	// from the list
 	Explosion	*	e = eused, * ep = nullptr;
 	while (e)
 	{
+		// Remember next entry in list
 		Explosion	*	en = e->next;
+
+		// Increment phase (radius)
 		e->r++;
+
+		// Advance every fourth frame
 		if (!(e->r & 3))
 		{
+			// Draw or erase outer perimeter depending on growing or
+			// shrinking explosion phase
 			if (e->r <= 64)
 				bmmc_circle(&sbm, &scr, e->x, e->y, e->r >> 2, 1);
 			else
 				bmmc_circle(&sbm, &scr, e->x, e->y, 33 - (e->r >> 2), 0);
 		}
+
+		// End of explosion live
 		if (e->r == 128)
 		{
+			// Remove explosion from used list
 			if (ep)
 				ep->next = e->next;
 			else
 				eused = e->next;
+
+			// Prepend it to free list
 			e->next = efree;
 			efree = e;
 		}
 		else
 			ep = e;
 
+		// Next explosion in list
 		e = en;
 	}
 }
 
+// Initialize defending missile list
 void missile_init(void)
 {
 	mused = nullptr;
@@ -120,31 +301,47 @@ void missile_init(void)
 	missiles[7].next = nullptr;
 }
 
+// Add a new defending missile
 void missile_start(int sx, int sy, int tx, int ty)
 {
-	if (mfree)
+	// Check if entry in free list and missile in silo remaining
+	if (mfree && nmissiles > 0)
 	{
+		// Detach from free list
 		Missile	*	m = mfree;
 		mfree = m->next;
+
+		// Attach to active list
 		m->next = mused;
 		mused = m;
 
+		// Initialize start and target coordinates
 		m->sx = sx >> 1; m->x = sx >> 1;
 		m->sy = sy; m->y = sy;
 		m->tx = tx >> 1;
 		m->ty = ty;
 
+		// Initialize line drawing parameters
 		m->dy = m->sy - m->ty;
 		m->dx = m->tx - m->sx;
+		m->stepx = 1;
 		if (m->dx < 0)
+		{
 			m->dx = -m->dx;
+			m->stepx = -1;
+		}
 
 		m->d = m->dy - m->dx;
 		m->dx *= 2;
 		m->dy *= 2;
+
+		// Remove missile from silo
+		nmissiles--;
+		status_missiles(nmissiles);
 	}
 }
 
+// Animate all active missiles
 void missile_animate(void)
 {
 	Missile	*	m = mused, * mp = nullptr;
@@ -152,6 +349,7 @@ void missile_animate(void)
 	{
 		Missile	*	mn = m->next;
 
+		// Advance missile position using one step of Bresenham
 		if (m->d >= 0)
 		{
 			m->y--;
@@ -159,18 +357,18 @@ void missile_animate(void)
 		}
 		if (m->d < 0)
 		{
-			if (m->tx < m->sx)
+			m->x += m->stepx;
-				m->x--;
-			else
-				m->x++;
 			m->d += m->dy;
 		}
 
-		if (bmmc_get(&sbm, m->x, m->y) == 1 || m->y == m->ty)
+		// Check if target reached
+		if (m->y == m->ty)
 		{
+			// If so, clear line and start explosion
 			bmmcu_line(&sbm, m->sx * 2, m->sy, m->tx * 2, m->ty, 0);
 			explosion_start(m->x * 2, m->y);
 
+			// Remove from active list
 			if (mp)
 				mp->next = m->next;
 			else
@@ -180,6 +378,7 @@ void missile_animate(void)
 		}
 		else
 		{
+			// Draw new pixel in missile trace
 			bmmc_put(&sbm, m->x * 2, m->y, 3);
 			mp = m;
 		}
@@ -188,6 +387,7 @@ void missile_animate(void)
 	}
 }
 
+// Initialize incomming ICBM list
 void icbm_init(void)
 {
 	iused = nullptr;
@@ -197,9 +397,10 @@ void icbm_init(void)
 	icbms[15].next = nullptr;
 }
 
+// Add a new ICBM to the attacking set
 void icbm_start(int sx, int sy, int tx, int ty)
 {
-	if (ifree)
+	if (icbmcount && ifree)
 	{
 		Missile	*	m = ifree;
 		ifree = m->next;
@@ -210,16 +411,22 @@ void icbm_start(int sx, int sy, int tx, int ty)
 		m->sy = sy; m->y = sy;
 		m->tx = tx >> 1;
 		m->ty = ty;
-		m->cnt = 4;
+		m->cnt = 0;
 
 		m->dy = m->ty - m->sy;
 		m->dx = m->tx - m->sx;
+		m->stepx = 1;		
 		if (m->dx < 0)
+		{
 			m->dx = -m->dx;
+			m->stepx = -1;
+		}
 
 		m->d = m->dy - m->dx;
 		m->dx *= 2;
 		m->dy *= 2;
+
+		icbmcount--;
 	}
 }
 
@@ -230,14 +437,16 @@ void icbm_animate(void)
 	{
 		Missile	*	mn = m->next;
 
-		m->cnt--;
+		// Check speed of ICBMs
-
+		m->cnt += icbmspeed;
-		if (!m->cnt)
+		while (m->cnt > 0)
 		{
+			m->cnt -= 32;
+
+			// Draw pixel in trace
 			bmmc_put(&sbm, m->x * 2, m->y, 2);			
 
-			m->cnt = 4;
+			// Advance using Bresenham
-
 			if (m->d >= 0)
 			{
 				m->y++;
@@ -245,80 +454,126 @@ void icbm_animate(void)
 			}
 			if (m->d < 0)
 			{
-				if (m->tx < m->sx)
+				m->x += m->stepx;
-					m->x--;
-				else
-					m->x++;
 				m->d += m->dy;
 			}
 
+			// Check if colliding with cloud or target reached
 			if (bmmc_get(&sbm, m->x * 2, m->y) == 1 || m->y == m->ty)
 			{
+				// If so, clear trace and start explosion
 				bmmcu_line(&sbm, m->sx * 2, m->sy, m->tx * 2, m->ty, 0);
 				explosion_start(m->x * 2, m->y);
 
+				// Check if we hit the ground
 				if (m->y == m->ty)
 				{
+					// If so, find matching city
 					int	x = m->x * 2;
 					char	ix;
 					if (x > 160)
-						ix = (x - 202) / 32 + 3;
+						ix = ((x - 202) >> 5) + 3;
 					else
-						ix = (x - 58) / 32;
+						ix = (x - 58) >> 5;
-					cities[ix] = false;
+
-					spr_show(ix + 1, false);
+					// Destroy, destroy, annihilate, kill, kill
+					if (cities[ix])
+					{
+						ncities--;
+						cities[ix] = false;
+						spr_show(ix + 1, false);
+					}
 				}
 
+				// Add score for destroyed ICBM
+				score_inc(0, 25);
 
+				// Remove from list
 				if (mp)
 					mp->next = m->next;
 				else
 					iused = m->next;
 				m->next = ifree;
 				ifree = m;
-			}
+				m = nullptr;
-			else
+
-			{
+				// End loop early
-				bmmc_put(&sbm, m->x * 2, m->y, 1);
+				break;
-				mp = m;
 			}
 		}
-		else
+
+		// If ICBM still in flight
+		if (m)
+		{
+			// Remember for list management
 			mp = m;
+			// Draw white head
+			bmmc_put(&sbm, m->x * 2, m->y, 1);
+		}
 
 		m = mn;
 	}
 }
 
-void mountains_init(void)
+// Initialize game screen
+void screen_init(void)
 {
+	// Clean up
+	bmmcu_rect_fill(&sbm, 0, 8, 320, 184, 0);
+	
+	// Draw bottom
 	bmmcu_rect_fill(&sbm, 0, 192, 320, 8, 3);
 	bmmc_quad_fill(&sbm, &scr, 0, 192, 16, 184, 32, 184, 48, 192, MixedColors[3][3]);
 	bmmc_quad_fill(&sbm, &scr, 136, 192, 152, 184, 176, 184, 192, 192, MixedColors[3][3]);
 	bmmc_quad_fill(&sbm, &scr, 272, 192, 288, 184, 304, 184, 320, 192, MixedColors[3][3]);
+
+	// Show cities
+	for(char i=0; i<3; i++)
+	{
+		if (cities[i + 0])
+			spr_set(i + 1, true, 70 + 32 * i, 222, 65, 15, false, false, false);		
+		if (cities[i + 3])
+			spr_set(i + 4, true, 214 + 32 * i, 222, 65, 15, false, false, false);		
+	}
 }
 
+// Clear inner area of screen
+void screen_clear(void)
+{
+	bmmcu_rect_fill(&sbm, 0, 8, 320, 176, 0);	
+}
+
+// Interrupt routine for joystick control, called by raster IRQ at bottom
+// of screen
+
 __interrupt void joy_interrupt()
 {
-	joy_poll(1);
+	// Poll joystick
+	joy_poll(0);
 
-	CrossX += joyx[1]; CrossY += joyy[1];
+	// Move crosshair coordinates
+	CrossX += 2 * joyx[0]; CrossY += 2 * joyy[0];
 
+	// Stop at edges of screen
 	if (CrossX < 8)
 		CrossX = 8;
 	else if (CrossX > 312)
 		CrossX = 312;
-	if (CrossY < 16)
+	if (CrossY < 20)
-		CrossY = 16;
+		CrossY = 20;
 	else if (CrossY > 172)
 		CrossY = 172;
 
+	// Move crosshair sprite
 	spr_move(0, CrossX + 14, CrossY + 40);	
 
-	if (joyb[1])
+	// Check button
+	if (joyb[0])
 	{
+		// Avoid quickfire and bouncing
 		if (CrossDelay == 0)
 		{
+			// Request fire from non interrupt code
 			CrossP = true;
 			CrossDelay = 4;
 		}
@@ -327,64 +582,267 @@ __interrupt void joy_interrupt()
 		CrossDelay--;
 }
 
+enum GameState
+{
+	GS_READY,		// Getting ready
+	GS_LEVEL,		// Show level message
+	GS_PLAYING,		// Playing the game
+	GS_BONUS,		// Landed on pad
+	GS_ARMAGEDDON, 	// Show end game animation
+	GS_END			// Wait for restart
+};
+
+// State of the game
+struct Game
+{
+	GameState	state;	
+	byte		count, level;
+
+}	TheGame;	// Only one game, so global variable
+
+// Character buffer for some texts
+char	cbuffer[10];
+
+void game_state(GameState state)
+{
+
+	TheGame.state = state;
+
+	switch(state)
+	{
+	case GS_READY:	
+		// Start of new game
+		score_reset();
+		screen_init();
+		char_write(40, 100, s"READY PLAYER 1", 3);
+
+		// New cities
+		for(char i=0; i<6; i++)
+			cities[i] = true;
+		ncities = 6;
+		TheGame.count = 60;
+
+		// Starting at level 1
+		TheGame.level = 0;
+		break;
+
+	case GS_LEVEL:
+		// Advance to next level
+		TheGame.level++;
+		utoa(TheGame.level ,cbuffer, 10);
+		screen_clear();
+		char_write(96, 100, s"LEVEL", 3);
+		char_write(96 + 16 * 6, 100, cbuffer, 3);
+		TheGame.count = 30;
+		break;
+
+	case GS_PLAYING:
+		// Avoid old fire request
+		CrossP = false;
+
+		// Setup display
+		screen_init();
+		missile_init();
+		explosion_init();
+		icbm_init();
+
+		// A new set of 30 missiles
+		nmissiles = 30;
+		status_missiles(nmissiles);
+
+		// Game parameters based on level
+		if (TheGame.level < 112)
+			icbmspeed = 8 + TheGame.level;
+		else
+			icbmspeed = 120;
+
+		if (TheGame.level < 50)
+			icbmcount = 5 + TheGame.level / 2;
+		else
+			icbmcount = 30;
+
+		TheGame.count = 15;
+		break;
+
+	case GS_BONUS:
+	{
+		// Show bonus
+
+		unsigned bonus = ncities * 50 + nmissiles * 5;
+		utoa(bonus, cbuffer, 10);
+
+		char_write(96, 100, s"BONUS", 3);
+		char_write(96 + 16 * 6, 100, cbuffer, 3);
+
+		score_inc(0, bonus);
+		TheGame.count = 30;
+	}	break;
+
+	case GS_ARMAGEDDON:
+		TheGame.count = 0;
+		break;
+
+	case GS_END:
+		char_write(104, 92, s"THE END", 0);
+		TheGame.count = 120;
+		break;
+	}
+}
+
+// Main game play code
+void game_play(void)
+{
+	// Check if fire request
+	if (CrossP)
+	{
+		// Find lauch site
+		int	sx = 160;
+		if (CrossX < 120)
+			sx = 24;
+		else if (CrossX > 200)
+			sx = 296
+
+		// Fire missile
+		missile_start(sx, 184, CrossX, CrossY);
+
+		// Reset request
+		CrossP = false;
+	}
+
+	// Wait for next ICMB to enter the game
+	if (!--TheGame.count)
+	{	
+		// Pick target city
+		char ci;
+		do {
+			ci = rand() & 7;
+		} while (ci >= 6 || !cities[ci]);
+
+		int	cx;
+		if (ci < 3)
+			cx = 58 + 32 * ci;
+		else
+			cx = 202 + 32 * (ci - 3);
+
+		// Launch ICBM
+		icbm_start((rand() & 0xff) + 32, 0, cx, 184);
+
+		// Next lauch time
+		TheGame.count = 8 + (rand() & 63);
+	}
+
+	// Advance defending missiles by four pixels
+	for(char i=0; i<4; i++)		
+		missile_animate();
+
+	// Advance ICBMs
+	icbm_animate();
+
+	// Show explosions
+	explosion_animate();
+}
+
+// Main game loop, entered every VSYNC, slower if too busy with explosions
+void game_loop(void)
+{
+	switch(TheGame.state)
+	{
+	case GS_READY:
+		if (!--TheGame.count)
+			game_state(GS_LEVEL);
+		break;
+	case GS_LEVEL:
+		if (!--TheGame.count)
+			game_state(GS_PLAYING);
+		break;
+
+	case GS_PLAYING:
+		game_play();
+
+		// Check for level and game end coditions
+		if (!icbmcount && !iused && !eused)
+			game_state(GS_BONUS);
+		else if (ncities == 0)
+			game_state(GS_ARMAGEDDON);
+		break;
+
+	case GS_BONUS:
+		if (!--TheGame.count)
+			game_state(GS_LEVEL);
+		break;
+
+	case GS_ARMAGEDDON:
+		// Draw end game animation
+		TheGame.count++;		
+		bmmc_circle(&sbm, &scr, 160, 100, TheGame.count, 1);
+		explosion_animate();
+		if (TheGame.count == 90)
+			game_state(GS_END);
+		break;
+
+	case GS_END:
+		if (!--TheGame.count)
+			game_state(GS_READY);
+		break;
+	}
+}
+
+// Interrupts for status line and joystick routine
 RIRQCode	bottom, top;
 
 int main(void)
 {
+	// Activate trampoline
 	mmap_trampoline();
 
+	// Disable CIA interrupts, we do not want interference
+	// with our joystick interrupt
+	cia_init();
+
+	// Copy assets
 	mmap_set(MMAP_RAM);
 	memcpy(Sprites, MissileSprites, 1024);
 	memcpy(Charset, MissileChars, 2048);
 	mmap_set(MMAP_NO_ROM);
 
-	vic_setmode(VICM_HIRES_MC, Color1, Hires);
+	// Clean out screen space
-	spr_init(Color1);
-
-	// initialize raster IRQ
-	rirq_init(true);
-
-	vic.color_back = VCOL_BLACK;
-	vic.color_border = VCOL_BLACK;
-
 	memset(Color1, 0x18, 1000);
 	memset(Color2, 0x06, 1000);
 	memset(Hires, 0, 8000);
 	memset(Color2 + 40 * 23, 0x07, 80);
 
-	bm_init(&sbm, Hires, 40, 25);
+	// initialize raster IRQ
-	missile_init();
+	rirq_init(true);
-	explosion_init();
-	icbm_init();
-	mountains_init();
 
+	// Switch to hires mode
+	vic_setmode(VICM_HIRES_MC, Color1, Hires);
+	spr_init(Color1);
+
+	// Black background and border
+	vic.color_back = VCOL_BLACK;
+	vic.color_border = VCOL_BLACK;
+
+	// Init bitmap
+	bm_init(&sbm, Hires, 40, 25);
+
+	// Init status line
+	status_init();
+
+	// Init cross hair sprite
 	spr_set(0, true, CrossX + 14, CrossY + 40, 64, 1, false, false, false);
 
-	for(char i=0; i<3; i++)
+	// Build to multicolor highres at top of screen
-	{
-		spr_set(i + 1, true, 70 + 32 * i, 222, 65, 15, false, false, false);		
-		spr_set(i + 4, true, 214 + 32 * i, 222, 65, 15, false, false, false);		
-
-		cities[i + 0] = true;
-		cities[i + 3] = true;
-	}
-
-	// Build the switch to normal IRQ
 	rirq_build(&top, 3);
-	// Change color for ceiling
 	rirq_delay(&top, 10);
 	rirq_write(&top, 1, &vic.ctrl1, VIC_CTRL1_BMM | VIC_CTRL1_DEN | VIC_CTRL1_RSEL | 3);
 	rirq_write(&top, 2, &vic.memptr, 0x28);
-	// place this at the bottom
 	rirq_set(0, 57, &top);
 
-	// Build the switch to normal IRQ
+	// Switch to text mode for status line and poll joystick at bottom
 	rirq_build(&bottom, 3);
 	rirq_write(&bottom, 0, &vic.memptr, 0x27);
 	rirq_write(&bottom, 1, &vic.ctrl1, VIC_CTRL1_DEN | VIC_CTRL1_RSEL | 3);
-	// Change color for ceiling
 	rirq_call(&bottom, 2, joy_interrupt);
-	// place this at the bottom
 	rirq_set(1, 250, &bottom);
 
 	// sort the raster IRQs
@@ -393,42 +851,12 @@ int main(void)
 	// start raster IRQ processing
 	rirq_start();
 
-	bool	launched = false;
+	// start game state machine
+	game_state(GS_READY);
 	for(;;)
 	{
-		if (CrossP)
+		game_loop();
-		{
+		rirq_wait();
-			int	sx = 160;
-			if (CrossX < 120)
-				sx = 24;
-			else if (CrossX > 200)
-				sx = 296
-			missile_start(sx, 184, CrossX, CrossY);
-			CrossP = false;
-		}
-
-		if (!(rand() & 63))
-		{	
-			char ci;
-			do {
-				ci = rand() & 7;
-			} while (ci >= 6 || !cities[ci]);
-
-			int	cx;
-			if (ci < 3)
-				cx = 58 + 32 * ci;
-			else
-				cx = 202 + 32 * (ci - 3);
-
-			icbm_start((rand() & 0xff) + 32, 0, cx, 184);
-		}
-
-		for(char i=0; i<4; i++)
-			missile_animate();
-		icbm_animate();
-		explosion_animate();
-
-		vic_waitFrame();
 	}
 
 	return 0;

samples/games/snake.c

@@ -233,8 +233,8 @@ void game_loop(void)
 		break;
 	case GS_PLAYING:
 		// Check player input on every frame
-		joy_poll(1);
+		joy_poll(0);
-		snake_control(&TheGame.snake, joyx[1], joyy[1]);
+		snake_control(&TheGame.snake, joyx[0], joyy[0]);
 
 		if (!--TheGame.count)
 		{

samples/scrolling/cgrid8way.c

@@ -388,8 +388,8 @@ int main(void)
 	for(;;)
 	{
 		// Check the joystick
-		joy_poll(1);
+		joy_poll(0);
-		if (joyx[1] == 1)
+		if (joyx[0] == 1)
 		{
 			// Move to the right
 			if (gridX < 24)
@@ -399,7 +399,7 @@ int main(void)
 				scroll_left();
 			}
 		}
-		else if (joyx[1] == -1)
+		else if (joyx[0] == -1)
 		{
 			// Move to the left
 			if (gridX > 0)
@@ -409,7 +409,7 @@ int main(void)
 				scroll_right();
 			}
 		}
-		else if (joyy[1] == 1)
+		else if (joyy[0] == 1)
 		{
 			// Move down
 			if (gridY < 39)
@@ -419,7 +419,7 @@ int main(void)
 				scroll_up();
 			}
 		}
-		else if (joyy[1] == -1)
+		else if (joyy[0] == -1)
 		{
 			// Move up
 			if (gridY > 0)

samples/sprites/joycontrol.c

@@ -33,11 +33,11 @@ int main(void)
 	for(;;)
 	{
 		// Poll joytick
-		joy_poll(1);
+		joy_poll(0);
 
 		// Change position according to joystick
-		spx += joyx[1];
+		spx += joyx[0];
-		spy += joyy[1];
+		spy += joyy[0];
 
 		// Move sprites on screen
 		spr_move(0, spx, spy);