tfv: add initial page flip support

gr-sim/gr-sim.c

@@ -60,45 +60,37 @@ unsigned char a,y,x;
 #define FLASH	0xF3
 #define TEMP	0xFA
 
+static int text_mode=0xff;
+static int text_page_1=0x00;
+static int hires_on=0x00;
+static int mixed_graphics=0xff;
 
-/* Soft Switches */
-#define TXTCLR	0xc050
-#define TXTSET	0xc051
-#define	MIXCLR	0xc052
-#define MIXSET	0xc053
-#define	LOWSCR	0xc054
-#define HISCR	0xc055
-#define LORES	0xc056
-#define HIRES	0xc057
-
-static int text_mode=1;
-static int text_page_1=1;
-static int hires_on=0;
-static int mixed_graphics=1;
-
-static void soft_switch(unsigned short address) {
+void soft_switch(unsigned short address) {
 
 	switch(address) {
 		case TXTCLR:	// $c050
-			text_mode=0;
+			text_mode=0x00;
 			break;
 		case TXTSET:	// $c051
-			text_mode=1;
+			text_mode=0xff;
 			break;
 		case MIXCLR:	// $c052
-			mixed_graphics=0;
+			mixed_graphics=0x00;
 			break;
 		case MIXSET:	// $c053
-			mixed_graphics=1;
+			mixed_graphics=0xff;
 			break;
 		case LOWSCR:	// $c054
-			text_page_1=1;
+			text_page_1=0x00;
+			break;
+		case HISCR:	// $c055
+			text_page_1=0xff;
 			break;
 		case LORES:	// $c056
-			hires_on=0;
+			hires_on=0x00;
 			break;
 		case HIRES:	// $c057
-			hires_on=1;
+			hires_on=0xff;
 			break;
 		default:
 			fprintf(stderr,"Unknown soft switch %x\n",address);
@@ -106,6 +98,24 @@ static void soft_switch(unsigned short address) {
 	}
 }
 
+int soft_switch_read(unsigned short address) {
+
+	switch(address) {
+		case TEXT_RD:	// $c01a
+			return text_mode;
+		case MIXED_RD:	// $c01b
+			return mixed_graphics;
+		case PAGE2_RD:	// $c01c
+			return text_page_1;
+		case HIRES_RD:	// $c01d
+			return hires_on;
+		default:
+			fprintf(stderr,"Unknown soft switch read %x\n",address);
+			break;
+	}
+	return 0;
+}
+
 static SDL_Surface *sdl_screen=NULL;
 
 int grsim_input(void) {
@@ -258,11 +268,16 @@ int grsim_update(void) {
 	unsigned int *t_pointer;
 	int text_start,text_end,gr_start,gr_end;
 
+	int gr_addr,gr_addr_hi;
+	int temp_col;
+
+	/* point to SDL output pixels */
 	t_pointer=((Uint32 *)sdl_screen->pixels);
 
 	text_start=0; text_end=0;
 	gr_start=0;gr_end=GR_YSIZE;
 
+	/* get the proper modes */
 	if (text_mode) {
 		text_start=0; text_end=TEXT_YSIZE;
 		gr_start=0; gr_end=0;
@@ -272,23 +287,50 @@ int grsim_update(void) {
 		gr_start=0; gr_end=40;
 	}
 
+	/* do the top 40/48 if in graphics mode */
 	for(y=gr_start;y<gr_end;y++) {
+
 		for(j=0;j<PIXEL_Y_SCALE;j++) {
+
+			gr_addr=gr_addr_lookup[y/2];
+			gr_addr_hi=y%2;
+
+			/* adjust for page */
+			if (text_page_1) {
+				gr_addr+=0x400;
+			}
+
 			for(x=0;x<GR_XSIZE;x++) {
+
+				if (gr_addr_hi) {
+					temp_col=(ram[gr_addr]&0xf0)>>4;
+				}
+				else {
+					temp_col=ram[gr_addr]&0x0f;
+				}
+
 				for(i=0;i<PIXEL_X_SCALE;i++) {
-					*t_pointer=color[scrn(x,y)];
+					*t_pointer=color[temp_col];
 					t_pointer++;
 				}
+				gr_addr++;
 			}
 		}
 	}
 
-
+	/* Do the remaining text */
 	for(y=text_start;y<text_end;y++) {
 		for(j=0;j<TEXT_Y_SCALE;j++) {
 			for(x=0;x<TEXT_XSIZE;x++) {
-				ch=ram[gr_addr_lookup[y]+x];
-	//			printf("%x ",ch);
+
+				gr_addr=gr_addr_lookup[y];
+
+				/* adjust for page */
+				if (text_page_1) {
+					gr_addr+=0x400;
+				}
+
+				ch=ram[gr_addr+x];
 
 				if (ch&0x80) {
 					flash=0;
@@ -311,9 +353,6 @@ int grsim_update(void) {
 		/* 14 x 16 */
 		/* but font is 5x7 */
 
-		/* FIXME: handle page2 */
-
-
 		if (j>13) bit_set=0;
 		else if (i>11) bit_set=0;
 		else bit_set=(a2_font[ch][j/2])&(1<<(5-(i/2)));
@@ -1147,6 +1186,8 @@ void basic_normal(void) {
 
 static unsigned short hlin_addr;
 static unsigned short hlin_hi;
+static unsigned short vlin_addr;
+static unsigned short vlin_hi;
 
 int hlin_continue(int width) {
 
@@ -1181,6 +1222,32 @@ int hlin(int page, int x1, int x2, int at) {
 	return 0;
 }
 
+int vlin(int page, int y1, int y2, int at) {
+
+	int i;
+
+	for(i=y1;i<y2;i++) {
+
+		vlin_addr=gr_addr_lookup[i/2];
+		vlin_hi=i&1;
+
+		vlin_addr+=(page*4)<<8;
+
+		vlin_addr+=at;
+
+		if (vlin_hi) {
+			ram[vlin_addr]=ram[vlin_addr]&0x0f;
+			ram[vlin_addr]|=ram[COLOR]&0xf0;
+		}
+		else {
+			ram[vlin_addr]=ram[vlin_addr]&0xf0;
+			ram[vlin_addr]|=ram[COLOR]&0x0f;
+		}
+	}
+
+	return 0;
+}
+
 int hlin_double_continue(int width) {
 
 	int i;

gr-sim/gr-sim.h

@@ -25,7 +25,9 @@ int hlin(int page, int x1, int x2, int at);
 int hlin_continue(int width);
 int hlin_double_continue(int width);
 int hlin_double(int page, int x1, int x2, int at);
-
+void soft_switch(unsigned short address);
+int soft_switch_read(unsigned short address);
+int vlin(int page, int y1, int y2, int at);
 int collision(int xx, int yy, int ground_color);
 
 #define APPLE_UP        11
@@ -49,3 +51,37 @@ int collision(int xx, int yy, int ground_color);
 #define COLOR_YELLOW	13
 #define COLOR_AQUA	14
 #define COLOR_WHITE	15
+
+/* Soft Switches */
+#define EIGHTYSTORE_OFF	0xc000	// page2 selects AUX ram
+#define EIGHTYSTORE_ON	0xc001	// page2 selects MAIN ram
+#define EIGHTYCOL_OFF	0xc00c	// Display 40 columns
+#define EIGHTYCOLO_ON	0xc00d	// Display 80 columns
+#define ALTCHAR_OFF	0xc00e	// Use primary charset
+#define ALTCHAR_ON	0xc00f	// Use alternate charset
+#define EIGHTYSTORE_RD	0xc018	// Read 80stor switch (R7)
+#define TEXT_RD		0xc01a	// Read text switch (R7)
+#define MIXED_RD	0xc01b	// Read mixed switch (R7)
+#define PAGE2_RD	0xc01c	// Read Page2 (R7)
+#define HIRES_RD	0xc01d	// Read HIRES (R7)
+#define ALTCHAR_RD	0xc01e	// Read ALTCHAR switch (R7)
+#define EIGHTYCOL_RD	0xc01f	// Read 80col switch (1==on) (R7)
+#define TXTCLR		0xc050  // Display GR
+#define TEXT_OFF	0xc050	// Display GR
+#define TXTSET		0xc051	// Display Text
+#define TEXT_ON		0xc051	// Display Text
+#define MIXED_OFF	0xc052	// Mixed Text Off
+#define MIXCLR		0xc052	// Mixed Text Off
+#define MIXED_ON	0xc053	// Mixed Text On
+#define MIXSET		0xc053	// Mixed Text On
+#define PAGE2_OFF	0xc054	// Use Page 1
+#define LOWSCR		0xc054	// Use Page 1
+#define PAGE2_ON	0xc055	// Use Page 2
+#define HISCR		0xc055	// Use Page 2
+#define HIRES_OFF	0xc056	// lowres mode
+#define LORES		0xc056	// lowres mode
+#define HIRES_ON	0xc057	// hires mode
+#define HIRES		0xc057	// hires mode
+#define DHIRES_ON	0xc05e	// double-hires on
+#define DHIRES_OFF	0xc05f	// double-hires off
+#define DHIRES_RD	0xc07f	// double-hires read

gr-sim/tfv.c

@@ -19,6 +19,8 @@
 #define LOOP	0x06
 #define MEMPTRL	0x07
 #define MEMPTRH	0x08
+#define DISP_PAGE	0x09
+#define DRAW_PAGE	0x0a
 
 /* stats */
 static unsigned char level=0;
@@ -34,16 +36,30 @@ static unsigned char map_x=5;
 static char tfv_x=15,tfv_y=19;
 static unsigned char ground_color;
 
+static void page_flip(void) {
+
+	if (ram[DISP_PAGE]==0) {
+		soft_switch(HISCR);
+		ram[DISP_PAGE]=1;
+		ram[DRAW_PAGE]=0;
+	}
+	else {
+		soft_switch(LOWSCR);
+		ram[DISP_PAGE]=0;
+		ram[DRAW_PAGE]=1;
+	}
+}
+
 static void draw_segment(void) {
 
 	for(ram[LOOP]=0;ram[LOOP]<4;ram[LOOP]++) {
 		ram[YY]=ram[YY]+ram[YADD];
 		if (ram[XX]==ram[MATCH]) color_equals(ram[COLOR1]*3);
 		else color_equals(ram[COLOR1]);
-		basic_vlin(10,ram[YY],9+ram[XX]);
+		vlin(ram[DRAW_PAGE],10,ram[YY],9+ram[XX]);
 		if (ram[XX]==ram[MATCH]) color_equals(ram[COLOR2]*3);
 		else color_equals(ram[COLOR2]);
-		if (ram[YY]!=34) basic_vlin(ram[YY],34,9+ram[XX]);
+		if (ram[YY]!=34) vlin(ram[DRAW_PAGE],ram[YY],34,9+ram[XX]);
 		ram[XX]++;
 	}
 	ram[YADD]=-ram[YADD];
@@ -66,6 +82,8 @@ static void draw_logo(void) {
 	ram[COLOR2]=0;
 	draw_segment();
 
+	page_flip();
+
 	grsim_update();
 }
 
@@ -1111,6 +1129,9 @@ int main(int argc, char **argv) {
 
 	grsim_init();
 
+	ram[DISP_PAGE]=0;
+	ram[DRAW_PAGE]=0;
+
 	home();
 	gr();