# HG changeset patch
# User Michael Pavone <pavone@retrodev.com>
# Date 1459125362 25200
# Node ID 04d8efe7a1f04051d297b378c8668b7a0aa53bd4
# Parent  9f575f77a157f58560707a72df858a75c7cb2736
Initial stab at video output and background color rendering. Fixed address decoding in address port write handler.

diff -r 9f575f77a157 -r 04d8efe7a1f0 Makefile
--- a/Makefile	Sun Mar 27 17:32:09 2016 -0700
+++ b/Makefile	Sun Mar 27 17:36:02 2016 -0700
@@ -7,7 +7,10 @@
 TARGETDIR:=release
 endif #DEBUG
 
-all : $(TARGETDIR)/s16
+CFLAGS:=$(shell pkg-config --cflags-only-I sdl2) $(CFLAGS)
+LDFLAGS:=$(shell pkg-config --libs sdl2)
+
+all : $(TARGETDIR) $(TARGETDIR)/s16 $(TARGETDIR)/asm
 
 clean :
 	rm -f $(TARGETDIR)/*.o $(TARGETDIR)/s16 $(TARGETDIR)/asm
@@ -15,11 +18,11 @@
 $(TARGETDIR) : 
 	mkdir $(TARGETDIR)
 
-$(TARGETDIR)/s16 : $(TARGETDIR)/main.o $(TARGETDIR)/cpu.o $(TARGETDIR)/vdp.o
+$(TARGETDIR)/s16 : $(TARGETDIR)/main.o $(TARGETDIR)/cpu.o $(TARGETDIR)/vdp.o $(TARGETDIR)/system_sdl.o
 	$(CC) -o $@ $^ $(LDFLAGS)
 	
 $(TARGETDIR)/asm : $(TARGETDIR)/asm.o $(TARGETDIR)/cpu.o
 		$(CC) -o $@ $^ $(LDFLAGS)
 
-$(TARGETDIR)/%.o : src/%.c $(TARGETDIR)
+$(TARGETDIR)/%.o : src/%.c
 	$(CC) $(CFLAGS) -c -o $@ $<
diff -r 9f575f77a157 -r 04d8efe7a1f0 bgcolor.s16
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/bgcolor.s16	Sun Mar 27 17:36:02 2016 -0700
@@ -0,0 +1,7 @@
+	ldim 0, r0
+	ldimh $FF, r0
+	outi 14, r0
+	ldim $F, r0
+	outi 15, r0
+done
+	bra done
diff -r 9f575f77a157 -r 04d8efe7a1f0 src/main.c
--- a/src/main.c	Sun Mar 27 17:32:09 2016 -0700
+++ b/src/main.c	Sun Mar 27 17:36:02 2016 -0700
@@ -4,6 +4,7 @@
 #include <string.h>
 #include "cpu.h"
 #include "vdp.h"
+#include "system.h"
 
 #define CYCLES_PER_FRAME (832*262)
 
@@ -140,6 +141,11 @@
 	context.proc->port_handlers[PORT_VRAM_ADDRESS].write = address_port_write;
 	context.proc->port_handlers[PORT_VRAM_ADDRESS].read = address_port_read;
 	context.proc->port_handlers[PORT_VRAM_DATA].write = data_port_write;
+	
+	if (!system_init(640, 480)) {
+		return 1;
+	}
+	
 	run_console(&context);
 	return 0;
 }
diff -r 9f575f77a157 -r 04d8efe7a1f0 src/vdp.c
--- a/src/vdp.c	Sun Mar 27 17:32:09 2016 -0700
+++ b/src/vdp.c	Sun Mar 27 17:36:02 2016 -0700
@@ -1,18 +1,23 @@
 #include <stdint.h>
 #include <string.h>
 #include "vdp.h"
+#include "system.h"
 
 void vdp_init(vdp *context, uint32_t clock_div)
 {
 	memset(context, 0, sizeof(vdp));
-	context->clock_inc = clock_div;
+	//clock div specifies the pixel clock divider
+	//but our emulation step is half that fast
+	context->clock_inc = clock_div*2;
+	context->drawbuffer = context->linebuffers;
+	context->readbuffer = context->linebuffers+320;
 }
 
 void vdp_run(vdp *context, uint32_t target)
 {
 	while (context->cycles < target)
 	{
-		context->hcounter++;
+		context->hcounter+=2;
 		if (context->hcounter == 416) {
 			context->hcounter = 0;
 			context->vcounter++;
@@ -21,6 +26,29 @@
 			}
 		}
 		//TODO: do rendering stuff here
+		//Draw to framebuffer
+		if (context->vcounter > 8 && context->vcounter < 249 && context->hcounter < 320) {
+			if (!context->hcounter && context->vcounter == 9) {
+				context->framebuffer = system_get_framebuffer(&context->pitch);
+				//pitch is in terms of bytes, but we want it in terms of pixels
+				context->pitch /= sizeof(uint16_t);
+			}
+			uint16_t *dest = context->framebuffer + (context->vcounter - 9) * context->pitch + context->hcounter;
+			if (context->status & VDP_STATUS_ENABLED && context->vcounter > 16 && context->vcounter < 241) {
+				*dest = context->cram[0x3F & context->readbuffer[context->hcounter]];
+				dest++;
+				*dest = context->cram[0x3F & context->readbuffer[context->hcounter+1]];
+			} else {
+				//Display is disabled or we're in the border area, draw the background color
+				*dest = *context->cram;
+				dest++;
+				*dest = *context->cram;
+			}
+		} else if(!context->hcounter && context->vcounter == 249) {
+			system_framebuffer_updated();
+			context->framebuffer = NULL;
+		}
+		//Handle the FIFO
 		if (context->status & VDP_STATUS_FIFO) {
 			switch (context->fifo_dest)
 			{
@@ -51,13 +79,13 @@
 void vdp_write_address(vdp *context, uint16_t value)
 {
 	context->status &= ~VDP_STATUS_FIFO;
-	if (value & 0x8000) {
+	if (!(value & 0x8000)) {
 		context->fifo_dest = FIFO_DEST_VRAM;
 		context->dest_offset = (value & (sizeof(context->vram) -1))/2;
-	} else if (value & 0xFF00 == 0xFE00) {
+	} else if ((value & 0xFF00) == 0xFE00) {
 		context->fifo_dest = FIFO_DEST_SRAM;
 		context->dest_offset = (value & (sizeof(context->sram) -1))/2;
-	} else if (value & 0xFF00 == 0xFF00) {
+	} else if ((value & 0xFF00) == 0xFF00) {
 		context->fifo_dest = FIFO_DEST_CRAM;
 		context->dest_offset = (value & (sizeof(context->cram) -1))/2;
 	} 
diff -r 9f575f77a157 -r 04d8efe7a1f0 src/vdp.h
--- a/src/vdp.h	Sun Mar 27 17:32:09 2016 -0700
+++ b/src/vdp.h	Sun Mar 27 17:36:02 2016 -0700
@@ -2,8 +2,12 @@
 #define VDP_H_
 
 typedef struct {
+	uint16_t *framebuffer;
+	uint8_t  *drawbuffer;
+	uint8_t  *readbuffer;
 	uint32_t cycles;
 	uint32_t clock_inc;
+	int      pitch;
 	
 	uint16_t fifo;
 	uint16_t dest_offset;
@@ -16,6 +20,7 @@
 	uint16_t hscroll;
 	
 	uint16_t vram[32*512];
+	uint8_t  linebuffers[320*2];
 	uint16_t sram[64*2];
 	uint16_t cram[64];
 	
@@ -29,9 +34,10 @@
 	FIFO_DEST_CRAM
 };
 
-#define VDP_STATUS_FIFO 1
-#define VDP_STATUS_VRAM 2
-#define VDP_STATUS_SRAM 4
+#define VDP_STATUS_FIFO    1
+#define VDP_STATUS_VRAM    2
+#define VDP_STATUS_SRAM    4
+#define VDP_STATUS_ENABLED 8
 
 void vdp_init(vdp *context, uint32_t clock_div);
 void vdp_run(vdp *context, uint32_t target);