altos/stm-vga: Fix DMA reset to load scanline each time

If we load the scanline register while DMA is running, it doesn't
actually get reloaded until after the first transfer from the next
line, leaving a weird jog in the middle of the screen.

Also flip to SPI1, as Bdale is using that on the 1802 board.

Signed-off-by: Keith Packard <keithp@keithp.com>

1 files changed, 71 insertions, 0 deletions

diff --git a/src/stm-vga/ao_demo.c b/src/stm-vga/ao_demo.c
index 582e4156..3b582cc2 100644
--- a/src/stm-vga/ao_demo.c
+++ b/src/stm-vga/ao_demo.c
@@ -24,6 +24,67 @@
 #include <ao_boot.h>
 #include <ao_vga.h>
 
+struct ao_task ball_task;
+
+#define BALL_WIDTH	5
+#define BALL_HEIGHT	5
+
+static int	ball_x;
+static int	ball_y;
+static int	ball_dx, ball_dy;
+
+uint8_t		ball_enable;
+
+void
+ao_ball(void)
+{
+	ball_dx = 1;
+	ball_dy = 1;
+	ball_x = 0;
+	ball_y = 0;
+	for (;;) {
+		while (!ball_enable)
+			ao_sleep(&ball_enable);
+		for (;;) {
+			ao_solid(AO_ALLONES,
+				 AO_ALLONES,
+				 ao_vga_fb + ball_y * AO_VGA_STRIDE,
+				 AO_VGA_STRIDE,
+				 ball_x,
+				 BALL_WIDTH,
+				 BALL_HEIGHT);
+			ao_delay(AO_MS_TO_TICKS(10));
+			ao_solid(AO_ALLONES,
+				 AO_ALLONES,
+				 ao_vga_fb + ball_y * AO_VGA_STRIDE,
+				 AO_VGA_STRIDE,
+				 ball_x,
+				 BALL_WIDTH,
+				 BALL_HEIGHT);
+			if (!ball_enable)
+				break;
+			ball_x += ball_dx;
+			ball_y += ball_dy;
+			if (ball_x + BALL_WIDTH > AO_VGA_WIDTH) {
+				ball_x = AO_VGA_WIDTH - BALL_WIDTH;
+				ball_dx = -ball_dx;
+			}
+			if (ball_x < 0) {
+				ball_x = -ball_x;
+				ball_dx = -ball_dx;
+			}
+			if (ball_y + BALL_HEIGHT > AO_VGA_HEIGHT) {
+				ball_y = AO_VGA_HEIGHT - BALL_HEIGHT;
+				ball_dy = -ball_dy;
+			}
+			if (ball_y < 0) {
+				ball_y = -ball_y;
+				ball_dy = -ball_dy;
+			}
+		}
+	}
+}
+
 static void
 ao_video_toggle(void)
 {
@@ -31,8 +92,17 @@ ao_video_toggle(void)
 	ao_vga_enable(ao_cmd_lex_i);
 }
 
+static void
+ao_ball_toggle(void)
+{
+	ao_cmd_decimal();
+	ball_enable = ao_cmd_lex_i;
+	ao_wakeup(&ball_enable);
+}
+
 __code struct ao_cmds ao_demo_cmds[] = {
 	{ ao_video_toggle, "V\0Toggle video" },
+	{ ao_ball_toggle, "B\0Toggle ball" },
 	{ 0, NULL }
 };
 
@@ -52,6 +122,7 @@ main(void)
 	ao_vga_init();
 	ao_usb_init();
 
+	ao_add_task(&ball_task, ao_ball, "ball");
 	ao_cmd_register(&ao_demo_cmds[0]);
 
 	ao_start_scheduler();