Switch to virtual function table

Use one pointer to table of functions instead of scattered
bunch of function pointers. Different versions of these tables
can be constructed in compile time.

Also, bitmap memory alignment now depends only on SSE2/AVX2 support
and is constant for every width. That simplifies code without
noticeable performance penalty.

1 files changed, 52 insertions, 18 deletions

diff --git a/libass/ass_bitmap.h b/libass/ass_bitmap.h
index 901adc70..7817d33a 100644
--- a/libass/ass_bitmap.h
+++ b/libass/ass_bitmap.h
@@ -19,6 +19,7 @@
 #ifndef LIBASS_BITMAP_H
 #define LIBASS_BITMAP_H
 
+#include <stdbool.h>
 #include <ft2build.h>
 #include FT_GLYPH_H
 
@@ -29,6 +30,51 @@ typedef struct ass_synth_priv ASS_SynthPriv;
 ASS_SynthPriv *ass_synth_init(double);
 void ass_synth_done(ASS_SynthPriv *priv);
 
+struct segment;
+typedef void (*FillSolidTileFunc)(uint8_t *buf, ptrdiff_t stride, int set);
+typedef void (*FillHalfplaneTileFunc)(uint8_t *buf, ptrdiff_t stride,
+                                      int32_t a, int32_t b, int64_t c, int32_t scale);
+typedef void (*FillGenericTileFunc)(uint8_t *buf, ptrdiff_t stride,
+                                    const struct segment *line, size_t n_lines,
+                                    int winding);
+
+typedef void (*BitmapBlendFunc)(uint8_t *dst, intptr_t dst_stride,
+                                uint8_t *src, intptr_t src_stride,
+                                intptr_t height, intptr_t width);
+typedef void (*BitmapMulFunc)(uint8_t *dst, intptr_t dst_stride,
+                              uint8_t *src1, intptr_t src1_stride,
+                              uint8_t *src2, intptr_t src2_stride,
+                              intptr_t width, intptr_t height);
+
+typedef void (*BeBlurFunc)(uint8_t *buf, intptr_t w, intptr_t h,
+                           intptr_t stride, uint16_t *tmp);
+
+#define C_ALIGN_ORDER 5
+
+typedef struct {
+    int align_order;  // log2(alignment)
+
+    // rasterizer functions
+#if CONFIG_RASTERIZER
+    int tile_order;  // log2(tile_size)
+    FillSolidTileFunc fill_solid;
+    FillHalfplaneTileFunc fill_halfplane;
+    FillGenericTileFunc fill_generic;
+#endif
+
+    // blend functions
+    BitmapBlendFunc add_bitmaps, sub_bitmaps;
+    BitmapMulFunc mul_bitmaps;
+
+    // be blur function
+    BeBlurFunc be_blur;
+} BitmapEngine;
+
+extern const BitmapEngine ass_bitmap_engine_c;
+extern const BitmapEngine ass_bitmap_engine_sse2;
+extern const BitmapEngine ass_bitmap_engine_avx2;
+
+
 typedef struct {
     size_t n_contours, max_contours;
     size_t *contours;
@@ -46,12 +92,15 @@ typedef struct {
     unsigned char *buffer;      // h * stride buffer
 } Bitmap;
 
+Bitmap *alloc_bitmap(const BitmapEngine *engine, int w, int h);
+Bitmap *copy_bitmap(const BitmapEngine *engine, const Bitmap *src);
+void ass_free_bitmap(Bitmap *bm);
+
 Bitmap *outline_to_bitmap(ASS_Renderer *render_priv,
                           ASS_Outline *outline, int bord);
 
-Bitmap *alloc_bitmap(int w, int h);
-
-void ass_synth_blur(ASS_SynthPriv *priv_blur, int opaque_box, int be,
+void ass_synth_blur(const BitmapEngine *engine,
+                    ASS_SynthPriv *priv_blur, int opaque_box, int be,
                     double blur_radius, Bitmap *bm_g, Bitmap *bm_o);
 
 /**
@@ -65,30 +114,15 @@ int outline_to_bitmap2(ASS_Renderer *render_priv,
                        ASS_Outline *outline, ASS_Outline *border,
                        Bitmap **bm_g, Bitmap **bm_o);
 
-void ass_free_bitmap(Bitmap *bm);
 void ass_gauss_blur(unsigned char *buffer, unsigned *tmp2,
                     int width, int height, int stride,
                     unsigned *m2, int r, int mwidth);
 int be_padding(int be);
-void be_blur_c(uint8_t *buf, intptr_t w,
-               intptr_t h, intptr_t stride,
-               uint16_t *tmp);
 void be_blur_pre(uint8_t *buf, intptr_t w,
                  intptr_t h, intptr_t stride);
 void be_blur_post(uint8_t *buf, intptr_t w,
                   intptr_t h, intptr_t stride);
-void add_bitmaps_c(uint8_t *dst, intptr_t dst_stride,
-                   uint8_t *src, intptr_t src_stride,
-                   intptr_t height, intptr_t width);
-void sub_bitmaps_c(uint8_t *dst, intptr_t dst_stride,
-                   uint8_t *src, intptr_t src_stride,
-                   intptr_t height, intptr_t width);
-void mul_bitmaps_c(uint8_t *dst, intptr_t dst_stride,
-                   uint8_t *src1, intptr_t src1_stride,
-                   uint8_t *src2, intptr_t src2_stride,
-                   intptr_t w, intptr_t h);
 void shift_bitmap(Bitmap *bm, int shift_x, int shift_y);
 void fix_outline(Bitmap *bm_g, Bitmap *bm_o);
-Bitmap *copy_bitmap(const Bitmap *src);
 
 #endif                          /* LIBASS_BITMAP_H */