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Oct 16, 2025
Merged

Consolidate all compositing primitive ops #133

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4 changes: 3 additions & 1 deletion Makefile
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Original file line number Diff line number Diff line change
Expand Up @@ -31,7 +31,6 @@ libtwin.a_files-y = \
src/button.c \
src/fixed.c \
src/label.c \
src/primitive.c \
src/trig.c \
src/convolve.c \
src/font.c \
Expand Down Expand Up @@ -72,6 +71,9 @@ libtwin.a_files-$(CONFIG_LOGGING) += src/log.c
libtwin.a_files-$(CONFIG_CURSOR) += src/cursor.c

# Rendering backends
# Screen compositing operations (always needed for screen buffer management)
libtwin.a_files-y += src/screen-ops.c
# Renderer implementations (draw-builtin.c includes all compositing operations)
libtwin.a_files-$(CONFIG_RENDERER_BUILTIN) += src/draw-builtin.c
libtwin.a_files-$(CONFIG_RENDERER_PIXMAN) += src/draw-pixman.c
libtwin.a_cflags-$(CONFIG_RENDERER_PIXMAN) += $(shell pkg-config --cflags pixman-1)
Expand Down
23 changes: 22 additions & 1 deletion scripts/gen-composite-decls.py
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Expand Up @@ -62,6 +62,18 @@ def generate_2operand_decls():
return decls


def generate_screen_ops_decls():
"""
Generate declarations for essential screen compositing functions
These are implemented in screen-ops.c and always available
"""
return [
"twin_op_func _twin_rgb16_source_argb32;",
"twin_op_func _twin_argb32_over_argb32;",
"twin_op_func _twin_argb32_source_argb32;",
]


def generate_vectorized_decls():
"""
Generate declarations for vectorized functions
Expand All @@ -78,7 +90,10 @@ def generate_header():
return """/*
* Compositing operation function declarations
*
* These functions are generated by macros in src/primitive.c
* These functions are generated by macros in:
* - src/draw-builtin.c (when CONFIG_RENDERER_BUILTIN=y)
* - src/screen-ops.c (always available)
*
* This file is auto-generated by the build system - DO NOT EDIT
*/

Expand All @@ -105,13 +120,19 @@ def generate_footer():
def main():
print(generate_header())

print("\n/* Essential screen compositing (always available from screen-ops.c) */")
for decl in generate_screen_ops_decls():
print(decl)

print("\n/* 3-operand compositing: _twin_{src}_in_{msk}_{op}_{dst} */")
print("/* Total: 2 ops * 3 dsts * 4 srcs * 4 msks = 96 functions */")
print("/* Only available when CONFIG_RENDERER_BUILTIN=y */")
for decl in generate_3operand_decls():
print(decl)

print("\n/* 2-operand compositing: _twin_{src}_{op}_{dst} */")
print("/* Total: 2 ops * 3 dsts * 4 srcs = 24 functions */")
print("/* Only available when CONFIG_RENDERER_BUILTIN=y */")
for decl in generate_2operand_decls():
print(decl)

Expand Down
229 changes: 229 additions & 0 deletions src/draw-builtin.c
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Original file line number Diff line number Diff line change
Expand Up @@ -15,6 +15,235 @@

#include "twin_private.h"

/* Compositing Primitive Operations
*
* The following section contains low-level pixel compositing operations
* that implement Porter-Duff compositing algebra for various pixel formats.
* These functions are generated via C preprocessor macros to create all
* combinations of source/mask/destination format operations.
*/

static inline twin_argb32_t in_over(twin_argb32_t dst,
twin_argb32_t src,
twin_a8_t msk)
{
uint16_t t1, t2, t3, t4;
twin_a8_t a;

switch (msk) {
case 0:
return dst;
case 0xff:
break;
default:
src = (twin_in(src, 0, msk, t1) | twin_in(src, 8, msk, t2) |
twin_in(src, 16, msk, t3) | twin_in(src, 24, msk, t4));
break;
}
if (!src)
return dst;
a = ~(src >> 24);
switch (a) {
case 0:
return src;
case 0xff:
dst = (twin_add(src, dst, 0, t1) | twin_add(src, dst, 8, t2) |
twin_add(src, dst, 16, t3) | twin_add(src, dst, 24, t4));
break;
default:
dst = (twin_over(src, dst, 0, a, t1) | twin_over(src, dst, 8, a, t2) |
twin_over(src, dst, 16, a, t3) | twin_over(src, dst, 24, a, t4));
break;
}
return dst;
}

static inline twin_argb32_t in(twin_argb32_t src, twin_a8_t msk)
{
uint16_t t1, t2, t3, t4;

return (twin_in(src, 0, msk, t1) | twin_in(src, 8, msk, t2) |
twin_in(src, 16, msk, t3) | twin_in(src, 24, msk, t4));
}

static inline twin_argb32_t over(twin_argb32_t dst, twin_argb32_t src)
{
uint16_t t1, t2, t3, t4;
twin_a8_t a;

if (!src)
return dst;
a = ~(src >> 24);
switch (a) {
case 0:
return src;
case 0xff:
dst = (twin_add(src, dst, 0, t1) | twin_add(src, dst, 8, t2) |
twin_add(src, dst, 16, t3) | twin_add(src, dst, 24, t4));
break;
default:
dst = (twin_over(src, dst, 0, a, t1) | twin_over(src, dst, 8, a, t2) |
twin_over(src, dst, 16, a, t3) | twin_over(src, dst, 24, a, t4));
break;
}
return dst;
}

static inline twin_argb32_t rgb16_to_argb32(twin_rgb16_t v)
{
return twin_rgb16_to_argb32(v);
}

static inline twin_argb32_t a8_to_argb32(twin_a8_t v)
{
return v << 24;
}

static inline twin_rgb16_t argb32_to_rgb16(twin_argb32_t v)
{
return twin_argb32_to_rgb16(v);
}

static inline twin_a8_t argb32_to_a8(twin_argb32_t v)
{
return v >> 24;
}

/* Naming convention
*
* _twin_<src>_in_<msk>_op_<dst>
*
* Use 'c' for constant
*/

#define dst_argb32_get (*dst.argb32)
#define dst_argb32_set (*dst.argb32++) =
#define dst_rgb16_get (rgb16_to_argb32(*dst.rgb16))
#define dst_rgb16_set (*dst.rgb16++) = argb32_to_rgb16
#define dst_a8_get (a8_to_argb32(*dst.a8))
#define dst_a8_set (*dst.a8++) = argb32_to_a8

#define src_c (src.c)
#define src_argb32 (*src.p.argb32++)
#define src_rgb16 (rgb16_to_argb32(*src.p.rgb16++))
#define src_a8 (a8_to_argb32(*src.p.a8++))

#define msk_c (argb32_to_a8(msk.c))
#define msk_argb32 (argb32_to_a8(*msk.p.argb32++))
#define msk_rgb16 \
(0xff); \
(void) msk
#define msk_a8 (*msk.p.a8++)

#define CAT2(a, b) a##b
#define CAT3(a, b, c) a##b##c
#define CAT4(a, b, c, d) a##b##c##d
#define CAT6(a, b, c, d, e, f) a##b##c##d##e##f

#define _twin_in_op_name(src, op, msk, dst) \
CAT6(_twin_, src, _in_, msk, op, dst)

#define _twin_op_name(src, op, dst) CAT4(_twin_, src, op, dst)

#define MAKE_TWIN_in_over(__dst, __src, __msk) \
void _twin_in_op_name(__src, _over_, __msk, __dst)( \
twin_pointer_t dst, twin_source_u src, twin_source_u msk, int width) \
{ \
twin_argb32_t dst32; \
twin_argb32_t src32; \
twin_a8_t msk8; \
while (width--) { \
dst32 = CAT3(dst_, __dst, _get); \
src32 = CAT2(src_, __src); \
msk8 = CAT2(msk_, __msk); \
dst32 = in_over(dst32, src32, msk8); \
CAT3(dst_, __dst, _set)(dst32); \
} \
}

#define MAKE_TWIN_in_source(__dst, __src, __msk) \
void _twin_in_op_name(__src, _source_, __msk, __dst)( \
twin_pointer_t dst, twin_source_u src, twin_source_u msk, int width) \
{ \
twin_argb32_t dst32; \
twin_argb32_t src32; \
twin_a8_t msk8; \
while (width--) { \
src32 = CAT2(src_, __src); \
msk8 = CAT2(msk_, __msk); \
dst32 = in(src32, msk8); \
CAT3(dst_, __dst, _set)(dst32); \
} \
}

/* clang-format off */
#define MAKE_TWIN_in_op_msks(op, dst, src) \
CAT2(MAKE_TWIN_in_, op)(dst, src, argb32) \
CAT2(MAKE_TWIN_in_, op)(dst, src, rgb16) \
CAT2(MAKE_TWIN_in_, op)(dst, src, a8) \
CAT2(MAKE_TWIN_in_, op)(dst, src, c)
/* clang-format on */

#define MAKE_TWIN_in_op_srcs_msks(op, dst) \
MAKE_TWIN_in_op_msks(op, dst, argb32) MAKE_TWIN_in_op_msks(op, dst, rgb16) \
MAKE_TWIN_in_op_msks(op, dst, a8) MAKE_TWIN_in_op_msks(op, dst, c)

#define MAKE_TWIN_in_op_dsts_srcs_msks(op) \
MAKE_TWIN_in_op_srcs_msks(op, argb32) MAKE_TWIN_in_op_srcs_msks(op, rgb16) \
MAKE_TWIN_in_op_srcs_msks(op, a8)

MAKE_TWIN_in_op_dsts_srcs_msks(over) MAKE_TWIN_in_op_dsts_srcs_msks(source)

#define MAKE_TWIN_over(__dst, __src) \
void _twin_op_name(__src, _over_, __dst)(twin_pointer_t dst, \
twin_source_u src, int width) \
{ \
twin_argb32_t dst32; \
twin_argb32_t src32; \
while (width--) { \
dst32 = CAT3(dst_, __dst, _get); \
src32 = CAT2(src_, __src); \
dst32 = over(dst32, src32); \
CAT3(dst_, __dst, _set)(dst32); \
} \
}

#define MAKE_TWIN_source(__dst, __src) \
void _twin_op_name(__src, _source_, __dst)(twin_pointer_t dst, \
twin_source_u src, int width) \
{ \
twin_argb32_t dst32; \
twin_argb32_t src32; \
while (width--) { \
src32 = CAT2(src_, __src); \
dst32 = src32; \
CAT3(dst_, __dst, _set)(dst32); \
} \
}

/* clang-format off */
#define MAKE_TWIN_op_srcs(op, dst) \
CAT2(MAKE_TWIN_, op)(dst, argb32) \
CAT2(MAKE_TWIN_, op)(dst, rgb16) \
CAT2(MAKE_TWIN_, op)(dst, a8) \
CAT2(MAKE_TWIN_, op)(dst, c)

#define MAKE_TWIN_op_dsts_srcs(op) \
MAKE_TWIN_op_srcs(op, argb32) \
MAKE_TWIN_op_srcs(op, rgb16) \
MAKE_TWIN_op_srcs(op, a8)

MAKE_TWIN_op_dsts_srcs(over);
MAKE_TWIN_op_dsts_srcs(source);

/* clang-format on */

/* Built-in Renderer Implementation
*
* The following section implements the twin_composite() and twin_fill()
* functions using the primitive operations defined above.
*/

/* op, src, dst */
static const twin_src_op comp2[2][4][3] = {
[TWIN_OVER] =
Expand Down
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