ppu: less magical lcdc constants

libgambatte/src/video.h

@@ -64,7 +64,7 @@ public:
 	}
 
 	void doEvent(unsigned char *const ifreg, const unsigned ly, const unsigned statReg, const unsigned lycReg) {
-		if (((statReg_ | statReg) & 0x08) && (!(statReg_ & 0x40) || ly != lycReg_))
+		if (((statReg_ | statReg) & lcdstat_m0irqen) && (!(statReg_ & lcdstat_lycirqen) || ly != lycReg_))
 			*ifreg |= 2;
 
 		statReg_ = statReg;

libgambatte/src/video/lcddef.h

@@ -0,0 +1,21 @@
+#ifndef LCDDEF_H
+#define LCDDEF_H
+
+namespace gambatte {
+
+enum { lcdc_bgen = 0x01,
+       lcdc_objen = 0x02,
+       lcdc_obj2x = 0x04,
+       lcdc_tdsel = 0x10,
+       lcdc_we = 0x20,
+       lcdc_en = 0x80 };
+
+enum { lcdstat_lycflag = 0x04,
+       lcdstat_m0irqen = 0x08,
+       lcdstat_m1irqen = 0x10,
+       lcdstat_m2irqen = 0x20,
+       lcdstat_lycirqen = 0x40 };
+
+}
+
+#endif

libgambatte/src/video/ppu.h

@@ -19,6 +19,7 @@
 #ifndef PPU_H
 #define PPU_H
 
+#include "lcddef.h"
 #include "video/ly_counter.h"
 #include "video/sprite_mapper.h"
 #include "gbint.h"