X-Git-Url: http://4ch.mooo.com/gitweb/?a=blobdiff_plain;f=src%2Flib%2Fmodex16%2F16render.c;h=8e6fa43624cd41be40f3b0b7fbd4ffbdb7809f53;hb=c1d3221afb5fe541d8c886ff66198329c153e48e;hp=198844081b005924553591da69f19964e53a89a7;hpb=568a26044aca96ac8b1c98b2bb119c62c55596d8;p=16.git

diff --git a/src/lib/modex16/16render.c b/src/lib/modex16/16render.c
index 19884408..8e6fa436 100755
--- a/src/lib/modex16/16render.c
+++ b/src/lib/modex16/16render.c
@@ -1,5 +1,5 @@
 /* Project 16 Source Code~
- * Copyright (C) 2012-2015 sparky4 & pngwen & andrius4669
+ * Copyright (C) 2012-2016 sparky4 & pngwen & andrius4669 & joncampbell123
  *
  * This file is part of Project 16.
  *
@@ -434,3 +434,39 @@ modexDrawSpritePBufRegion(page_t *page, int x, int y,
 		JNZ PLANE_LOOP	  ; do all 4 planes
     }
 }
+
+void modexDrawCharPBuf(page_t *page, int x/*for planar selection only*/, int y/*redundant, remove*/, word t, word col, word bgcol, word addr)
+{
+	/* vertical drawing routine by joncampbell123.
+	 *
+	 * optimize for VGA mode X planar memory to minimize the number of times we do I/O write to map mask register.
+	 * so, we enumerate over columns (not rows!) to draw every 4th pixel. bit masks are used because of the font bitmap.
+	 * 
+	 * NTS: addr defines what VGA memory address we use, "x" is redundant except to specify which of the 4 pixels we select in the map mask register. */
+	word drawaddr;
+	word colm, row;
+	byte fontbyte;
+	byte plane;
+	byte m1,m2;
+
+	plane = x & 3;
+	m1 = 0x80; // left half
+	m2 = 0x08; // right half
+	for (colm=0;colm < 4;colm++) {
+		drawaddr = addr;
+		modexSelectPlane(PLANE(plane));
+		for (row=0;row < 8;row++) {
+			fontbyte = romFontsData.l[row];
+			vga_state.vga_graphics_ram[drawaddr  ] = (fontbyte & m1) ? col : bgcol;
+			vga_state.vga_graphics_ram[drawaddr+1] = (fontbyte & m2) ? col : bgcol;
+			drawaddr += page->width >> 2;
+		}
+
+		m1 >>= 1;
+		m2 >>= 1;
+		if ((++plane) == 4) {
+			addr++;
+			plane = 0;
+		}
+	}
+}