Draw sprites from the planes with correct colorsvdp-hacking

1 files changed, 60 insertions, 2 deletions

diff --git a/vdp.c b/vdp.c
index 84ef056..f24ed1e 100644
--- a/vdp.c
+++ b/vdp.c
@@ -500,7 +500,7 @@ static void redraw_debug_sprite(vdp_context *context, uint32_t *fb, uint32_t til
 	}
 }
 
-static void redraw_debug_sprites_with_correct_colors(vdp_context * context, uint32_t *fb)
+static void redraw_debug_sprites_sat(vdp_context * context, uint32_t *fb)
 {
 	if (context->regs[REG_MODE_2] & BIT_MODE_5) {
 		uint16_t sat_address = mode5_sat_address(context);
@@ -528,6 +528,63 @@ static void redraw_debug_sprites_with_correct_colors(vdp_context * context, uint
 	}
 }
 
+static void redraw_debug_sprites_planes(vdp_context * context, uint32_t *fb)
+{
+	uint16_t vscroll_mask = 0x1F | (context->regs[REG_SCROLL] & 0x30) << 1;
+	uint16_t hscroll_mask = 0x1F;
+	uint16_t v_mul = 64;
+	switch(context->regs[REG_SCROLL] & 0x3)
+	{
+	case 0x1:
+		hscroll_mask = 0x3F;
+		v_mul = 128;
+		break;
+	case 0x2:
+		//TODO: Verify this behavior
+		v_mul = 0;
+		break;
+	case 0x3:
+		hscroll_mask = 0x7F;
+		v_mul = 256;
+		break;
+	}
+	for (unsigned plane = 0; plane < 3; plane++) {
+		uint16_t table_address = (context->regs[REG_SCROLL_A] << 10) & 0xE000;;
+		switch(plane)
+		{
+		case 1:
+			table_address = context->regs[REG_SCROLL_B] << 13 & 0xE000;
+			break;
+		case 2:
+			table_address = context->regs[REG_WINDOW] << 10;
+			if (context->regs[REG_MODE_4] & BIT_H40) {
+				table_address &= 0xF000;
+				v_mul = 128;
+				hscroll_mask = 0x3F;
+			} else {
+				table_address &= 0xF800;
+				v_mul = 64;
+				hscroll_mask = 0x1F;
+			}
+			vscroll_mask = 0x1F;
+			break;
+		}
+		const uint32_t bg_color = context->colors[context->regs[REG_BG_COLOR & 0x3F]];
+		for (uint16_t row = 0; row < 128; row++)
+		{
+			const uint16_t row_address = table_address + (row & vscroll_mask) * v_mul;
+			for (uint16_t col = 0; col < 128; col++)
+			{
+				const uint16_t address = row_address + (col & hscroll_mask) * 2;
+				const uint16_t entry = context->vdpmem[address] << 8 | context->vdpmem[address + 1];
+				const uint16_t tile_id = 0x7FF & entry;
+				const uint8_t pal = (entry >> 9 & 0x30) / 16u;
+				redraw_debug_sprite(context, fb, tile_id, pal);
+			}
+		}
+	}
+}
+
 #define VRAM_READ 0 //0000
 #define VRAM_WRITE 1 //0001
 //2 would trigger register write 0010
@@ -2105,7 +2162,8 @@ static void vdp_update_per_frame_debug(vdp_context *context)
 			}
 		}
 		
-		redraw_debug_sprites_with_correct_colors(context, fb);
+		redraw_debug_sprites_sat(context, fb);
+		redraw_debug_sprites_planes(context, fb);
 		render_framebuffer_updated(context->debug_fb_indices[VDP_DEBUG_VRAM], 1024);
 	}