git.y1.nz

commit 3872f632c5b53dd171d8766b938d3191a91a6575
parent 2113bc152bb7924630a2ea8733f4f77c89567ef4
Author: Toxa <untoxa@mail.ru>
Date:   Tue,  4 Jan 2022 12:03:18 +0300

gb/isr.h example of raw ISR vector construction

Diffstat:
A
gbdk-lib/examples/gb/isr_vector/Makefile
17
+++++++++++++++++
A
gbdk-lib/examples/gb/isr_vector/lcd_isr_wobble.c
23
+++++++++++++++++++++++

2 files changed, 40 insertions(+), 0 deletions(-)
diff --git a/gbdk-lib/examples/gb/isr_vector/Makefile b/gbdk-lib/examples/gb/isr_vector/Makefile
@@ -0,0 +1,17 @@
+CC	= ../../../bin/lcc -Wa-l -Wl-m -Wl-j -Wm-yS
+
+BINS	= lcd_isr_wobble.gb
+
+all:	$(BINS)
+
+compile.bat: Makefile
+	@echo "REM Automatically generated from Makefile" > compile.bat
+	@make -sn | sed y/\\//\\\\/ | grep -v make >> compile.bat
+
+# Compile and link single file in one pass
+%.gb:	%.c
+	$(CC) -o $@ $<
+
+clean:
+	rm -f *.o *.lst *.map *.gb *~ *.rel *.cdb *.ihx *.lnk *.sym *.asm *.noi
+
diff --git a/gbdk-lib/examples/gb/isr_vector/lcd_isr_wobble.c b/gbdk-lib/examples/gb/isr_vector/lcd_isr_wobble.c
@@ -0,0 +1,22 @@
+#include <gb/gb.h>
+#include <gb/isr.h>
+
+const uint8_t scanline_offsets_tbl[] = {0, 1, 2, 3, 3, 2, 1, 0, 0, 1, 2, 3, 3, 2, 1, 0};
+const uint8_t * scanline_offsets = scanline_offsets_tbl;
+
+void scanline_isr() CRITICAL INTERRUPT {
+    SCX_REG = scanline_offsets[LY_REG & (uint8_t)7];
+}
+ISR_VECTOR(VECTOR_STAT, scanline_isr)
+
+void main() {
+    LCDC_REG |= LCDCF_BG8000;
+    STAT_REG = STATF_MODE00;
+    set_interrupts(VBL_IFLAG | LCD_IFLAG);
+    SHOW_BKG;
+
+    while (TRUE) {
+        wait_vbl_done();        
+        scanline_offsets = &scanline_offsets_tbl[(uint8_t)(sys_time >> 2) & 0x07u];
+    }
+}
+

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