tfv: add multi-page plot routine

gr-sim/gr-sim.c

@@ -447,7 +447,7 @@ int color_equals(int new_color) {
 
 
 
-static void plot(void) {
+static void monitor_plot(void) {
 
 	unsigned char c;
 
@@ -499,7 +499,7 @@ int basic_plot(unsigned char xcoord, unsigned char ycoord) {
 		return -1;
 	}
 
-	plot();
+	monitor_plot();
 
 	return 0;
 }
@@ -577,7 +577,7 @@ static void vline(void) {
 	// f828
 vline_loop:
 	s=a;
-	plot();
+	monitor_plot();
 	a=s;
 	if (a<ram[V2]) {
 		a++;
@@ -1237,6 +1237,34 @@ int hlin_continue(int width) {
 }
 
 
+int plot(unsigned char xcoord, unsigned char ycoord) {
+
+	unsigned char c;
+
+	hlin_addr=gr_addr_lookup[ycoord/2];
+	hlin_addr+=(ram[DRAW_PAGE])<<8;
+	hlin_addr+=xcoord;
+
+	hlin_hi=ycoord&1;
+
+	if (hlin_hi) {
+		/* If odd, mask is 0xf0 */
+		ram[MASK]=0xf0;
+	}
+	else {
+		/* If even, mask is 0x0f */
+		ram[MASK]=0x0f;
+	}
+
+	c=ram[COLOR]&ram[MASK];
+	ram[hlin_addr]&=~ram[MASK];
+	ram[hlin_addr]|=c;
+
+	return 0;
+}
+
+
+
 int hlin(int page, int x1, int x2, int at) {
 
 	hlin_addr=gr_addr_lookup[at/2];

gr-sim/gr-sim.h

@@ -38,7 +38,7 @@ void htab(int xpos);
 void move_cursor(void);
 void print(char *string);
 void print_inverse(char *string);
-
+int plot(unsigned char xcoord, unsigned char ycoord);
 
 #define APPLE_UP        11
 #define APPLE_DOWN      10

gr-sim/tfv_flying.c

@@ -30,7 +30,151 @@ static unsigned char flying_map[64]= {
 #define LOWRES_W	40
 #define LOWRES_H	40
 
+#if 1
 
+//
+// Detailed version
+//
+//
+
+static int lookup_map(int x, int y) {
+
+	int color;
+
+	color=2;
+
+	x=x&MASK_X;
+	y=y&MASK_Y;
+
+	if ( ((y&0x3)==1) && ((x&7)==0) ) color=14;
+	if ( ((y&0x3)==3) && ((x&7)==4) ) color=14;
+
+
+	if ((y<8) && (x<8)) {
+		color=flying_map[(y*8)+x];
+	}
+
+
+	/* 2   2 2 2  2  2 2 2 */
+	/* 14 14 2 2  2  2 2 2 */
+	/* 2   2 2 2 14 14 2 2 */
+	/* 2   2 2 2  2  2 2 2 */
+
+	return color;
+
+}
+
+
+
+
+
+/* http://www.helixsoft.nl/articles/circle/sincos.htm */
+
+static double space_z=4.5; // height of the camera above the plane
+static int horizon=-2;    // number of pixels line 0 is below the horizon
+static double scale_x=20, scale_y=20;
+
+
+//void mode_7 (BITMAP *bmp, BITMAP *tile, fixed angle, fixed cx, fixed cy, MODE_7_PARAMS params)
+
+double BETA=-0.5;
+
+static int over_water;
+
+void draw_background_mode7(double angle, double cx, double cy) {
+
+	// current screen position
+	int screen_x, screen_y;
+
+	// the distance and horizontal scale of the line we are drawing
+	double distance, horizontal_scale;
+
+	// step for points in space between two pixels on a horizontal line
+	double  line_dx, line_dy;
+
+	// current space position
+	double space_x, space_y;
+	int map_color;
+
+	over_water=0;
+
+	/* Draw Sky */
+	/* Originally wanted to be fancy and have sun too, but no */
+	color_equals(COLOR_MEDIUMBLUE);
+	for(screen_y=0;screen_y<6;screen_y+=2) {
+		hlin_double(ram[DRAW_PAGE], 0, 40, screen_y);
+	}
+
+	/* Draw hazy horizon */
+	color_equals(COLOR_GREY);
+	hlin_double(ram[DRAW_PAGE], 0, 40, 6);
+
+
+	for (screen_y = 8; screen_y < LOWRES_H; screen_y++) {
+		// first calculate the distance of the line we are drawing
+		distance = (space_z * scale_y) / (screen_y + horizon);
+
+		// then calculate the horizontal scale, or the distance between
+		// space points on this horizontal line
+		horizontal_scale = (distance / scale_x);
+
+		// calculate the dx and dy of points in space when we step
+		// through all points on this line
+		line_dx = -sin(angle) * horizontal_scale;
+		line_dy = cos(angle) * horizontal_scale;
+
+		// calculate the starting position
+		space_x = cx + (distance * cos(angle)) - LOWRES_W/2 * line_dx;
+		space_y = cy + (distance * sin(angle)) - LOWRES_W/2 * line_dy;
+
+		// Move camera back a bit
+
+		double factor;
+
+		factor=space_z*BETA;
+
+//		factor=2.0*BETA;
+
+		space_x+=factor*cos(angle);
+		space_y+=factor*sin(angle);
+
+
+		// go through all points in this screen line
+		for (screen_x = 0; screen_x < LOWRES_W-1; screen_x++) {
+			// get a pixel from the tile and put it on the screen
+
+			map_color=lookup_map((int)space_x,(int)space_y);
+
+			//ram[COLOR]=map_color;
+			//ram[COLOR]|=map_color<<4;
+
+
+			color_equals(map_color);
+
+			if (screen_x==20) {
+				if (map_color==COLOR_DARKBLUE) over_water=1;
+				else over_water=0;
+			}
+
+			//hlin_double(ram[DRAW_PAGE], screen_x, screen_x+1,
+			//	screen_y);
+
+			plot(screen_x,screen_y);
+
+			// advance to the next position in space
+			space_x += line_dx;
+			space_y += line_dy;
+		}
+	}
+}
+
+#else
+
+//
+// Non-detailed version
+//
+//
+//
 
 static int lookup_map(int x, int y) {
 
@@ -161,6 +305,8 @@ void draw_background_mode7(double angle, double cx, double cy) {
 	}
 }
 
+#endif
+
 
 #define SHIPX	15