altos/draw: Add a reasonable API for drawing, add lines.lisp

Also, move the demo drawing into the stm-vga app and out of the vga
driver.

Signed-off-by: Keith Packard <keithp@keithp.com>

1 files changed, 128 insertions, 0 deletions

diff --git a/src/draw/ao_draw_int.h b/src/draw/ao_draw_int.h
new file mode 100644
index 00000000..6980147b
--- /dev/null
+++ b/src/draw/ao_draw_int.h
@@ -0,0 +1,128 @@
+/*
+ * Copyright © 2016 Keith Packard <keithp@keithp.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ */
+
+#ifndef _AO_DRAW_INT_H_
+#define _AO_DRAW_INT_H_
+
+static inline uint32_t
+ao_expand(uint32_t bits)
+{
+	return ~((bits & 1)-1);
+}
+
+static inline uint32_t
+ao_xor(uint8_t rop, uint32_t fg)
+{
+	fg = ao_expand(fg);
+
+	return (fg & ao_expand(rop >> 1)) |
+		(~fg & ao_expand(rop >> 3));
+}
+
+static inline uint32_t
+ao_and(uint8_t rop, uint32_t fg)
+{
+	fg = ao_expand(fg);
+
+	return (fg & ao_expand(rop ^ (rop >> 1))) |
+		(~fg & ao_expand((rop>>2) ^ (rop>>3)));
+}
+
+static inline uint32_t
+ao_left(uint32_t bits, int16_t shift) {
+	return bits >> shift;
+}
+
+static inline uint32_t
+ao_right(uint32_t bits, int16_t shift) {
+	return bits << shift;
+}
+
+static inline uint32_t
+ao_right_mask(int16_t x) {
+	if ((AO_UNIT - x) & AO_MASK)
+		return ao_left(AO_ALLONES,(AO_UNIT - x) & AO_MASK);
+	else
+		return 0;
+}
+
+static inline uint32_t
+ao_left_mask(int16_t x) {
+	if (x & AO_MASK)
+		return ao_right(AO_ALLONES, x & AO_MASK);
+	else
+		return 0;
+}
+
+static inline uint32_t
+ao_bits_mask(int16_t x, int16_t w) {
+	return ao_right(AO_ALLONES, x & AO_MASK) &
+		ao_left(AO_ALLONES,(AO_UNIT - (x + w)) & AO_MASK);
+}
+
+#define ao_mask_bits(x,w,l,n,r) { \
+    n = (w); \
+    r = ao_right_mask((x)+n); \
+    l = ao_left_mask(x); \
+    if (l) { \
+	n -= AO_UNIT - ((x) & AO_MASK); \
+	if (n < 0) { \
+	    n = 0; \
+	    l &= r; \
+	    r = 0; \
+	} \
+    } \
+    n >>= AO_SHIFT; \
+}
+
+static inline uint32_t
+ao_do_mask_rrop(uint32_t dst, uint32_t and, uint32_t xor, uint32_t mask) {
+	return (dst & (and | ~mask)) ^ (xor & mask);
+}
+
+static inline uint32_t
+ao_do_rrop(uint32_t dst, uint32_t and, uint32_t xor) {
+	return (dst & and) ^ xor;
+}
+
+void
+ao_blt(uint32_t		*src_line,
+       int16_t		src_stride,
+       int16_t		src_x,
+       uint32_t		*dst_line,
+       int16_t		dst_stride,
+       int16_t		dst_x,
+       int16_t		width,
+       int16_t		height,
+       uint8_t		rop,
+       uint8_t		reverse,
+       uint8_t		upsidedown);
+
+void
+ao_solid(uint32_t	and,
+	 uint32_t	xor,
+	 uint32_t	*dst,
+	 int16_t	dst_stride,
+	 int16_t	dst_x,
+	 int16_t	width,
+	 int16_t	height);
+
+int16_t
+ao_glyph(const struct ao_bitmap	*dst,
+	 int16_t		x,
+	 int16_t		y,
+	 uint8_t		c,
+	 uint8_t		rop);
+
+#endif /* _AO_DRAW_INT_H_ */