The Tor Browser: gfx/cairo/clip-invariant.patch@b8a032363ba2 (annotated)

gfx/cairo/clip-invariant.patch@b8a032363ba2 (annotated)

gfx/cairo/clip-invariant.patch

Thu, 22 Jan 2015 13:21:57 +0100

author: Michael Schloh von Bennewitz <michael@schloh.com>
date: Thu, 22 Jan 2015 13:21:57 +0100
branch: TOR_BUG_9701
changeset 15: b8a032363ba2
permissions: -rw-r--r--

Incorporate requested changes from Mozilla in review:
https://bugzilla.mozilla.org/show_bug.cgi?id=1123480#c6

 diff --git a/src/cairo-gl-surface.c b/src/cairo-gl-surface.c
 index 2acc8b5..019249e 100644
 --- a/src/cairo-gl-surface.c
 +++ b/src/cairo-gl-surface.c
@@ -2012,13 +2012,14 @@ typedef struct _cairo_gl_surface_span_renderer {
      cairo_gl_composite_setup_t setup;
 +    int xmin, xmax;
 +
      cairo_operator_t op;
      cairo_antialias_t antialias;
      cairo_gl_surface_t *dst;
      cairo_region_t *clip;
 -    cairo_composite_rectangles_t composite_rectangles;
      GLuint vbo;
      void *vbo_base;
      unsigned int vbo_size;
@@ -2049,11 +2050,11 @@ _cairo_gl_span_renderer_flush (cairo_gl_surface_span_renderer_t *renderer)
  	    cairo_region_get_rectangle (renderer->clip, i, &rect);
  	    glScissor (rect.x, rect.y, rect.width, rect.height);
 -	    glDrawArrays (GL_LINES, 0, count);
 +	    glDrawArrays (GL_QUADS, 0, count);
  	}
  	glDisable (GL_SCISSOR_TEST);
      } else {
 -	glDrawArrays (GL_LINES, 0, count);
 +	glDrawArrays (GL_QUADS, 0, count);
      }
  }
@@ -2134,72 +2135,87 @@ _cairo_gl_emit_span_vertex (cairo_gl_surface_span_renderer_t *renderer,
  static void
  _cairo_gl_emit_span (cairo_gl_surface_span_renderer_t *renderer,
 -		     int x1, int x2, int y, uint8_t alpha)
 +		     int x, int y1, int y2,
 +		     uint8_t alpha)
  {
      float *vertices = _cairo_gl_span_renderer_get_vbo (renderer, 2);
 -    _cairo_gl_emit_span_vertex (renderer, x1, y, alpha, vertices);
 -    _cairo_gl_emit_span_vertex (renderer, x2, y, alpha,
 +    _cairo_gl_emit_span_vertex (renderer, x, y1, alpha, vertices);
 +    _cairo_gl_emit_span_vertex (renderer, x, y2, alpha,
  			       vertices + renderer->vertex_size / 4);
  }
 -/* Emits the contents of the span renderer rows as GL_LINES with the span's
 - * alpha.
 - *
 - * Unlike the image surface, which is compositing into a temporary, we emit
 - * coverage even for alpha == 0, in case we're using an unbounded operator.
 - * But it means we avoid having to do the fixup.
 - */
 +static void
 +_cairo_gl_emit_rectangle (cairo_gl_surface_span_renderer_t *renderer,
 +			  int x1, int y1,
 +			  int x2, int y2,
 +			  int coverage)
 +{
 +    _cairo_gl_emit_span (renderer, x1, y1, y2, coverage);
 +    _cairo_gl_emit_span (renderer, x2, y2, y1, coverage);
 +}
 +
  static cairo_status_t
 -_cairo_gl_surface_span_renderer_render_row (
 -    void				*abstract_renderer,
 -    int					 y,
 -    const cairo_half_open_span_t	*spans,
 -    unsigned				 num_spans)
 +_cairo_gl_render_bounded_spans (void *abstract_renderer,
 +				int y, int height,
 +				const cairo_half_open_span_t *spans,
 +				unsigned num_spans)
  {
      cairo_gl_surface_span_renderer_t *renderer = abstract_renderer;
 -    int xmin = renderer->composite_rectangles.mask.x;
 -    int xmax = xmin + renderer->composite_rectangles.width;
 -    int prev_x = xmin;
 -    int prev_alpha = 0;
 -    unsigned i;
 -    int x_translate;
 -
 -    /* Make sure we're within y-range. */
 -    if (y < renderer->composite_rectangles.mask.y ||
 -	y >= renderer->composite_rectangles.mask.y +
 -	renderer->composite_rectangles.height)
 +
 +    if (num_spans == 0)
  	return CAIRO_STATUS_SUCCESS;
 -    x_translate = renderer->composite_rectangles.dst.x -
 -	renderer->composite_rectangles.mask.x;
 -    y += renderer->composite_rectangles.dst.y -
 -	renderer->composite_rectangles.mask.y;
 +    do {
 +	if (spans[0].coverage) {
 +	    _cairo_gl_emit_rectangle (renderer,
 +				      spans[0].x, y,
 +				      spans[1].x, y + height,
 +				      spans[0].coverage);
 +	}
 -    /* Find the first span within x-range. */
 -    for (i=0; i < num_spans && spans[i].x < xmin; i++) {}
 -    if (i>0)
 -	prev_alpha = spans[i-1].coverage;
 +	spans++;
 +    } while (--num_spans > 1);
 -    /* Set the intermediate spans. */
 -    for (; i < num_spans; i++) {
 -	int x = spans[i].x;
 +    return CAIRO_STATUS_SUCCESS;
 +}
 -	if (x >= xmax)
 -	    break;
 +static cairo_status_t
 +_cairo_gl_render_unbounded_spans (void *abstract_renderer,
 +				  int y, int height,
 +				  const cairo_half_open_span_t *spans,
 +				  unsigned num_spans)
 +{
 +    cairo_gl_surface_span_renderer_t *renderer = abstract_renderer;
 -	_cairo_gl_emit_span (renderer,
 -			     prev_x + x_translate, x + x_translate, y,
 -			     prev_alpha);
 +    if (num_spans == 0) {
 +	_cairo_gl_emit_rectangle (renderer,
 +				  renderer->xmin, y,
 +				  renderer->xmax, y + height,
 +				  0);
 +	return CAIRO_STATUS_SUCCESS;
 +    }
 -	prev_x = x;
 -	prev_alpha = spans[i].coverage;
 +    if (spans[0].x != renderer->xmin) {
 +	_cairo_gl_emit_rectangle (renderer,
 +				  renderer->xmin, y,
 +				  spans[0].x, y + height,
 +				  0);
      }
 -    if (prev_x < xmax) {
 -	_cairo_gl_emit_span (renderer,
 -			     prev_x + x_translate, xmax + x_translate, y,
 -			     prev_alpha);
 +    do {
 +	_cairo_gl_emit_rectangle (renderer,
 +				  spans[0].x, y,
 +				  spans[1].x, y + height,
 +				  spans[0].coverage);
 +	spans++;
 +    } while (--num_spans > 1);
 +
 +    if (spans[0].x != renderer->xmax) {
 +	_cairo_gl_emit_rectangle (renderer,
 +				  spans[0].x, y,
 +				  renderer->xmax, y + height,
 +				  0);
      }
      return CAIRO_STATUS_SUCCESS;
@@ -2274,8 +2290,6 @@ _cairo_gl_surface_create_span_renderer (cairo_operator_t	 op,
      cairo_gl_surface_t *dst = abstract_dst;
      cairo_gl_surface_span_renderer_t *renderer;
      cairo_status_t status;
 -    int width = rects->width;
 -    int height = rects->height;
      cairo_surface_attributes_t *src_attributes;
      GLenum err;
 diff --git a/src/cairo-image-surface.c b/src/cairo-image-surface.c
 index 48d8013..d52979d 100644
 --- a/src/cairo-image-surface.c
 +++ b/src/cairo-image-surface.c
@@ -1390,11 +1390,13 @@ typedef struct _cairo_image_surface_span_renderer {
      const cairo_pattern_t *pattern;
      cairo_antialias_t antialias;
 +    uint8_t *mask_data;
 +    uint32_t mask_stride;
 +
      cairo_image_surface_t *src;
      cairo_surface_attributes_t src_attributes;
      cairo_image_surface_t *mask;
      cairo_image_surface_t *dst;
 -
      cairo_composite_rectangles_t composite_rectangles;
  } cairo_image_surface_span_renderer_t;
@@ -1403,66 +1405,46 @@ _cairo_image_surface_span_render_row (
      int                                  y,
      const cairo_half_open_span_t        *spans,
      unsigned                             num_spans,
 -    cairo_image_surface_t               *mask,
 -    const cairo_composite_rectangles_t  *rects)
 +    uint8_t				*data,
 +    uint32_t				 stride)
  {
 -    int xmin = rects->mask.x;
 -    int xmax = xmin + rects->width;
      uint8_t *row;
 -    int prev_x = xmin;
 -    int prev_alpha = 0;
      unsigned i;
 -    /* Make sure we're within y-range. */
 -    y -= rects->mask.y;
 -    if (y < 0 || y >= rects->height)
 +    if (num_spans == 0)
  	return;
 -    row = (uint8_t*)(mask->data) + y*(size_t)mask->stride - xmin;
 -
 -    /* Find the first span within x-range. */
 -    for (i=0; i < num_spans && spans[i].x < xmin; i++) {}
 -    if (i>0)
 -	prev_alpha = spans[i-1].coverage;
 -
 -    /* Set the intermediate spans. */
 -    for (; i < num_spans; i++) {
 -	int x = spans[i].x;
 -
 -	if (x >= xmax)
 -	    break;
 -
 -	if (prev_alpha != 0) {
 -	    /* We implement setting rendering the most common single
 -	     * pixel wide span case to avoid the overhead of a memset
 -	     * call.  Open coding setting longer spans didn't show a
 -	     * noticeable improvement over memset. */
 -	    if (x == prev_x + 1) {
 -		row[prev_x] = prev_alpha;
 -	    }
 -	    else {
 -		memset(row + prev_x, prev_alpha, x - prev_x);
 -	    }
 +    row = data + y * stride;
 +    for (i = 0; i < num_spans - 1; i++) {
 +	if (! spans[i].coverage)
 +	    continue;
 +
 +	/* We implement setting the most common single pixel wide
 +	 * span case to avoid the overhead of a memset call.
 +	 * Open coding setting longer spans didn't show a
 +	 * noticeable improvement over memset.
 +	 */
 +	if (spans[i+1].x == spans[i].x + 1) {
 +	    row[spans[i].x] = spans[i].coverage;
 +	} else {
 +	    memset (row + spans[i].x,
 +		    spans[i].coverage,
 +		    spans[i+1].x - spans[i].x);
  	}
 -
 -	prev_x = x;
 -	prev_alpha = spans[i].coverage;
 -    }
 -
 -    if (prev_alpha != 0 && prev_x < xmax) {
 -	memset(row + prev_x, prev_alpha, xmax - prev_x);
      }
  }
  static cairo_status_t
 -_cairo_image_surface_span_renderer_render_row (
 +_cairo_image_surface_span_renderer_render_rows (
      void				*abstract_renderer,
      int					 y,
 +    int					 height,
      const cairo_half_open_span_t	*spans,
      unsigned				 num_spans)
  {
      cairo_image_surface_span_renderer_t *renderer = abstract_renderer;
 -    _cairo_image_surface_span_render_row (y, spans, num_spans, renderer->mask, &renderer->composite_rectangles);
 +    while (height--)
 +	_cairo_image_surface_span_render_row (y++, spans, num_spans, renderer->mask_data, renderer->mask_stride);
      return CAIRO_STATUS_SUCCESS;
  }
@@ -1517,11 +1499,11 @@ _cairo_image_surface_span_renderer_finish (void *abstract_renderer)
  		&dst->base,
  		src_attributes,
  		src->width, src->height,
 -		rects->width, rects->height,
 +		width, height,
  		rects->src.x, rects->src.y,
 , 0,		/* mask.x, mask.y */
  		rects->dst.x, rects->dst.y,
 -		rects->width, rects->height,
 +		width, height,
  		dst->clip_region);
  	}
      }
@@ -1567,7 +1549,7 @@ _cairo_image_surface_create_span_renderer (cairo_operator_t	 op,
      renderer->base.destroy = _cairo_image_surface_span_renderer_destroy;
      renderer->base.finish = _cairo_image_surface_span_renderer_finish;
 -    renderer->base.render_row = _cairo_image_surface_span_renderer_render_row;
 +    renderer->base.render_rows = _cairo_image_surface_span_renderer_render_rows;
      renderer->op = op;
      renderer->pattern = pattern;
      renderer->antialias = antialias;
@@ -1604,6 +1586,9 @@ _cairo_image_surface_create_span_renderer (cairo_operator_t	 op,
  	_cairo_image_surface_span_renderer_destroy (renderer);
  	return _cairo_span_renderer_create_in_error (status);
      }
 +
 +    renderer->mask_data = renderer->mask->data - rects->mask.x - rects->mask.y * renderer->mask->stride;
 +    renderer->mask_stride = renderer->mask->stride;
      return &renderer->base;
  }
 diff --git a/src/cairo-spans-private.h b/src/cairo-spans-private.h
 index e29a567..af3b38c 100644
 --- a/src/cairo-spans-private.h
 +++ b/src/cairo-spans-private.h
@@ -47,26 +47,24 @@ typedef struct _cairo_half_open_span {
   * surfaces if they want to composite spans instead of trapezoids. */
  typedef struct _cairo_span_renderer cairo_span_renderer_t;
  struct _cairo_span_renderer {
 +    /* Private status variable. */
 +    cairo_status_t status;
 +
      /* Called to destroy the renderer. */
      cairo_destroy_func_t	destroy;
 -    /* Render the spans on row y of the source by whatever compositing
 -     * method is required.  The function should ignore spans outside
 -     * the bounding box set by the init() function. */
 -    cairo_status_t (*render_row)(
 -	void				*abstract_renderer,
 -	int				 y,
 -	const cairo_half_open_span_t	*coverages,
 -	unsigned			 num_coverages);
 +    /* Render the spans on row y of the destination by whatever compositing
 +     * method is required. */
 +    cairo_warn cairo_status_t
 +    (*render_rows) (void *abstract_renderer,
 +		    int y, int height,
 +		    const cairo_half_open_span_t	*coverages,
 +		    unsigned num_coverages);
      /* Called after all rows have been rendered to perform whatever
       * final rendering step is required.  This function is called just
       * once before the renderer is destroyed. */
 -    cairo_status_t (*finish)(
 -	void		      *abstract_renderer);
 -
 -    /* Private status variable. */
 -    cairo_status_t status;
 +    cairo_status_t (*finish) (void *abstract_renderer);
  };
  /* Scan converter interface. */
 diff --git a/src/cairo-spans.c b/src/cairo-spans.c
 index af3b85f..69894c1 100644
 --- a/src/cairo-spans.c
 +++ b/src/cairo-spans.c
@@ -275,13 +275,15 @@ _cairo_scan_converter_create_in_error (cairo_status_t status)
  }
  static cairo_status_t
 -_cairo_nil_span_renderer_render_row (
 +_cairo_nil_span_renderer_render_rows (
      void				*abstract_renderer,
      int					 y,
 +    int					 height,
      const cairo_half_open_span_t	*coverages,
      unsigned				 num_coverages)
  {
      (void) y;
 +    (void) height;
      (void) coverages;
      (void) num_coverages;
      return _cairo_span_renderer_status (abstract_renderer);
@@ -310,7 +312,7 @@ _cairo_span_renderer_set_error (
  	ASSERT_NOT_REACHED;
      }
      if (renderer->status == CAIRO_STATUS_SUCCESS) {
 -	renderer->render_row = _cairo_nil_span_renderer_render_row;
 +	renderer->render_rows = _cairo_nil_span_renderer_render_rows;
  	renderer->finish = _cairo_nil_span_renderer_finish;
  	renderer->status = error;
      }
 diff --git a/src/cairo-tor-scan-converter.c b/src/cairo-tor-scan-converter.c
 index 29262c2..2b9fb1b 100644
 --- a/src/cairo-tor-scan-converter.c
 +++ b/src/cairo-tor-scan-converter.c
@@ -128,27 +128,29 @@ blit_with_span_renderer(
      cairo_span_renderer_t	*span_renderer,
      struct pool			*span_pool,
      int				 y,
 +    int				 height,
      int				 xmin,
      int				 xmax);
  static glitter_status_t
 -blit_empty_with_span_renderer (cairo_span_renderer_t *renderer, int y);
 +blit_empty_with_span_renderer (cairo_span_renderer_t *renderer, int y, int height);
  #define GLITTER_BLIT_COVERAGES_ARGS \
  	cairo_span_renderer_t *span_renderer, \
  	struct pool *span_pool
 -#define GLITTER_BLIT_COVERAGES(cells, y, xmin, xmax) do {		\
 +#define GLITTER_BLIT_COVERAGES(cells, y, height,xmin, xmax) do {	\
      cairo_status_t status = blit_with_span_renderer (cells,		\
  						     span_renderer,	\
  						     span_pool,		\
 -						     y, xmin, xmax);	\
 +						     y, height,		\
 +						     xmin, xmax);	\
      if (unlikely (status))						\
  	return status;							\
  } while (0)
 -#define GLITTER_BLIT_COVERAGES_EMPTY(y, xmin, xmax) do {		\
 -    cairo_status_t status = blit_empty_with_span_renderer (span_renderer, y); \
 +#define GLITTER_BLIT_COVERAGES_EMPTY(y, height, xmin, xmax) do {		\
 +    cairo_status_t status = blit_empty_with_span_renderer (span_renderer, y, height); \
      if (unlikely (status))						\
  	return status;							\
  } while (0)
@@ -309,8 +311,8 @@ typedef int grid_area_t;
  #define UNROLL3(x) x x x
  struct quorem {
 -    int quo;
 -    int rem;
 +    int32_t quo;
 +    int32_t rem;
  };
  /* Header for a chunk of memory in a memory pool. */
@@ -382,6 +384,7 @@ struct edge {
      /* Original sign of the edge: +1 for downwards, -1 for upwards
       * edges.  */
      int dir;
 +    int vertical;
  };
  /* Number of subsample rows per y-bucket. Must be GRID_Y. */
@@ -389,18 +392,28 @@ struct edge {
  #define EDGE_Y_BUCKET_INDEX(y, ymin) (((y) - (ymin))/EDGE_Y_BUCKET_HEIGHT)
 +struct bucket {
 +    /* Unsorted list of edges starting within this bucket. */
 +    struct edge *edges;
 +
 +    /* Set to non-zero if there are edges starting strictly within the
 +     * bucket. */
 +    unsigned     have_inside_edges;
 +};
 +
  /* A collection of sorted and vertically clipped edges of the polygon.
   * Edges are moved from the polygon to an active list while scan
   * converting. */
  struct polygon {
 -    /* The vertical clip extents. */
 +    /* The clip extents. */
 +    grid_scaled_x_t xmin, xmax;
      grid_scaled_y_t ymin, ymax;
      /* Array of edges all starting in the same bucket.	An edge is put
       * into bucket EDGE_BUCKET_INDEX(edge->ytop, polygon->ymin) when
       * it is added to the polygon. */
 -    struct edge **y_buckets;
 -    struct edge *y_buckets_embedded[64];
 +    struct bucket *y_buckets;
 +    struct bucket  y_buckets_embedded[64];
      struct {
  	struct pool base[1];
@@ -702,7 +715,6 @@ static void
  cell_list_fini(struct cell_list *cells)
  {
      pool_fini (cells->cell_pool.base);
 -    cell_list_init (cells);
  }
  /* Empty the cell list.  This is called at the start of every pixel
@@ -715,6 +727,26 @@ cell_list_reset (struct cell_list *cells)
      pool_reset (cells->cell_pool.base);
  }
 +static struct cell *
 +cell_list_alloc (struct cell_list *cells,
 +		 struct cell **cursor,
 +		 struct cell *tail,
 +		 int x)
 +{
 +    struct cell *cell;
 +
 +    cell = pool_alloc (cells->cell_pool.base, sizeof (struct cell));
 +    if (unlikely (NULL == cell))
 +	return NULL;
 +
 +    *cursor = cell;
 +    cell->next = tail;
 +    cell->x = x;
 +    cell->uncovered_area = 0;
 +    cell->covered_height = 0;
 +    return cell;
 +}
 +
  /* Find a cell at the given x-coordinate.  Returns %NULL if a new cell
   * needed to be allocated but couldn't be.  Cells must be found with
   * non-decreasing x-coordinate until the cell list is rewound using
@@ -737,22 +769,10 @@ cell_list_find (struct cell_list *cells, int x)
      }
      cells->cursor = cursor;
 -    if (tail->x == x) {
 +    if (tail->x == x)
  	return tail;
 -    } else {
 -	struct cell *cell;
 -
 -	cell = pool_alloc (cells->cell_pool.base, sizeof (struct cell));
 -	if (unlikely (NULL == cell))
 -	    return NULL;
 -	*cursor = cell;
 -	cell->next = tail;
 -	cell->x = x;
 -	cell->uncovered_area = 0;
 -	cell->covered_height = 0;
 -	return cell;
 -    }
 +    return cell_list_alloc (cells, cursor, tail, x);
  }
  /* Find two cells at x1 and x2.	 This is exactly equivalent
@@ -832,9 +852,8 @@ cell_list_find_pair(struct cell_list *cells, int x1, int x2)
  /* Add an unbounded subpixel span covering subpixels >= x to the
   * coverage cells. */
  static glitter_status_t
 -cell_list_add_unbounded_subspan(
 -    struct cell_list *cells,
 -    grid_scaled_x_t x)
 +cell_list_add_unbounded_subspan (struct cell_list *cells,
 +				 grid_scaled_x_t x)
  {
      struct cell *cell;
      int ix, fx;
@@ -907,20 +926,24 @@ cell_list_render_edge(
      struct edge *edge,
      int sign)
  {
 -    struct quorem x1 = edge->x;
 -    struct quorem x2 = x1;
      grid_scaled_y_t y1, y2, dy;
      grid_scaled_x_t dx;
      int ix1, ix2;
      grid_scaled_x_t fx1, fx2;
 -    x2.quo += edge->dxdy_full.quo;
 -    x2.rem += edge->dxdy_full.rem;
 -    if (x2.rem >= 0) {
 -	++x2.quo;
 -	x2.rem -= edge->dy;
 +    struct quorem x1 = edge->x;
 +    struct quorem x2 = x1;
 +
 +    if (! edge->vertical) {
 +	x2.quo += edge->dxdy_full.quo;
 +	x2.rem += edge->dxdy_full.rem;
 +	if (x2.rem >= 0) {
 +	    ++x2.quo;
 +	    x2.rem -= edge->dy;
 +	}
 +
 +	edge->x = x2;
      }
 -    edge->x = x2;
      GRID_X_TO_INT_FRAC(x1.quo, ix1, fx1);
      GRID_X_TO_INT_FRAC(x2.quo, ix2, fx2);
@@ -1026,6 +1049,7 @@ static void
  polygon_init (struct polygon *polygon)
  {
      polygon->ymin = polygon->ymax = 0;
 +    polygon->xmin = polygon->xmax = 0;
      polygon->y_buckets = polygon->y_buckets_embedded;
      pool_init (polygon->edge_pool.base,
 - sizeof (struct _pool_chunk),
@@ -1045,10 +1069,11 @@ polygon_fini (struct polygon *polygon)
   * receive new edges and clip them to the vertical range
   * [ymin,ymax). */
  static glitter_status_t
 -polygon_reset(
 -    struct polygon *polygon,
 -    grid_scaled_y_t ymin,
 -    grid_scaled_y_t ymax)
 +polygon_reset (struct polygon *polygon,
 +	       grid_scaled_x_t xmin,
 +	       grid_scaled_x_t xmax,
 +	       grid_scaled_y_t ymin,
 +	       grid_scaled_y_t ymax)
  {
      unsigned h = ymax - ymin;
      unsigned num_buckets = EDGE_Y_BUCKET_INDEX(ymax + EDGE_Y_BUCKET_HEIGHT-1,
@@ -1065,14 +1090,16 @@ polygon_reset(
      polygon->y_buckets =  polygon->y_buckets_embedded;
      if (num_buckets > ARRAY_LENGTH (polygon->y_buckets_embedded)) {
  	polygon->y_buckets = _cairo_malloc_ab (num_buckets,
 -					       sizeof (struct edge *));
 +					       sizeof (struct bucket));
  	if (unlikely (NULL == polygon->y_buckets))
  	    goto bail_no_mem;
      }
 -    memset (polygon->y_buckets, 0, num_buckets * sizeof (struct edge *));
 +    memset (polygon->y_buckets, 0, num_buckets * sizeof (struct bucket));
      polygon->ymin = ymin;
      polygon->ymax = ymax;
 +    polygon->xmin = xmin;
 +    polygon->xmax = xmax;
      return GLITTER_STATUS_SUCCESS;
   bail_no_mem:
@@ -1086,10 +1113,13 @@ _polygon_insert_edge_into_its_y_bucket(
      struct polygon *polygon,
      struct edge *e)
  {
 -    unsigned ix = EDGE_Y_BUCKET_INDEX(e->ytop, polygon->ymin);
 -    struct edge **ptail = &polygon->y_buckets[ix];
 +    unsigned j = e->ytop - polygon->ymin;
 +    unsigned ix = j / EDGE_Y_BUCKET_HEIGHT;
 +    unsigned offset = j % EDGE_Y_BUCKET_HEIGHT;
 +    struct edge **ptail = &polygon->y_buckets[ix].edges;
      e->next = *ptail;
      *ptail = e;
 +    polygon->y_buckets[ix].have_inside_edges |= offset;
  }
  inline static glitter_status_t
@@ -1115,30 +1145,53 @@ polygon_add_edge (struct polygon *polygon,
      dx = edge->line.p2.x - edge->line.p1.x;
      dy = edge->line.p2.y - edge->line.p1.y;
      e->dy = dy;
 -    e->dxdy = floored_divrem (dx, dy);
 -
 -    if (ymin <= edge->top)
 -	ytop = edge->top;
 -    else
 -	ytop = ymin;
 -    if (ytop == edge->line.p1.y) {
 -	e->x.quo = edge->line.p1.x;
 -	e->x.rem = 0;
 -    } else {
 -	e->x = floored_muldivrem (ytop - edge->line.p1.y, dx, dy);
 -	e->x.quo += edge->line.p1.x;
 -    }
 -
      e->dir = edge->dir;
 +
 +    ytop = edge->top >= ymin ? edge->top : ymin;
 +    ybot = edge->bottom <= ymax ? edge->bottom : ymax;
      e->ytop = ytop;
 -    ybot = edge->bottom < ymax ? edge->bottom : ymax;
      e->height_left = ybot - ytop;
 -    if (e->height_left >= GRID_Y) {
 -	e->dxdy_full = floored_muldivrem (GRID_Y, dx, dy);
 -    } else {
 +    if (dx == 0) {
 +	e->vertical = TRUE;
 +	e->x.quo = edge->line.p1.x;
 +	e->x.rem = 0;
 +	e->dxdy.quo = 0;
 +	e->dxdy.rem = 0;
  	e->dxdy_full.quo = 0;
  	e->dxdy_full.rem = 0;
 +
 +	/* Drop edges to the right of the clip extents. */
 +	if (e->x.quo >= polygon->xmax)
 +	    return GLITTER_STATUS_SUCCESS;
 +
 +	/* Offset vertical edges at the left side of the clip extents
 +	 * to just shy of the left side.  We depend on this when
 +	 * checking for possible intersections within the clip
 +	 * rectangle. */
 +	if (e->x.quo <= polygon->xmin) {
 +	    e->x.quo = polygon->xmin - 1;
 +	}
 +    } else {
 +	e->vertical = FALSE;
 +	e->dxdy = floored_divrem (dx, dy);
 +	if (ytop == edge->line.p1.y) {
 +	    e->x.quo = edge->line.p1.x;
 +	    e->x.rem = 0;
 +	} else {
 +	    e->x = floored_muldivrem (ytop - edge->line.p1.y, dx, dy);
 +	    e->x.quo += edge->line.p1.x;
 +	}
 +
 +	if (e->x.quo >= polygon->xmax && e->dxdy.quo >= 0)
 +	    return GLITTER_STATUS_SUCCESS;
 +
 +	if (e->height_left >= GRID_Y) {
 +	    e->dxdy_full = floored_muldivrem (GRID_Y, dx, dy);
 +	} else {
 +	    e->dxdy_full.quo = 0;
 +	    e->dxdy_full.rem = 0;
 +	}
      }
      _polygon_insert_edge_into_its_y_bucket (polygon, e);
@@ -1161,31 +1214,30 @@ active_list_init(struct active_list *active)
      active_list_reset(active);
  }
 -static void
 -active_list_fini(
 -    struct active_list *active)
 -{
 -    active_list_reset(active);
 -}
 -
  /* Merge the edges in an unsorted list of edges into a sorted
   * list. The sort order is edges ascending by edge->x.quo.  Returns
   * the new head of the sorted list. */
  static struct edge *
  merge_unsorted_edges(struct edge *sorted_head, struct edge *unsorted_head)
  {
 -    struct edge *head = unsorted_head;
      struct edge **cursor = &sorted_head;
      int x;
 -    while (NULL != head) {
 +    if (sorted_head == NULL) {
 +	sorted_head = unsorted_head;
 +	unsorted_head = unsorted_head->next;
 +	sorted_head->next = NULL;
 +	if (unsorted_head == NULL)
 +	    return sorted_head;
 +    }
 +
 +    do {
 +	struct edge *next = unsorted_head->next;
  	struct edge *prev = *cursor;
 -	struct edge *next = head->next;
 -	x = head->x.quo;
 -	if (NULL == prev || x < prev->x.quo) {
 +	x = unsorted_head->x.quo;
 +	if (x < prev->x.quo)
  	    cursor = &sorted_head;
 -	}
  	while (1) {
  	    UNROLL3({
@@ -1196,26 +1248,29 @@ merge_unsorted_edges(struct edge *sorted_head, struct edge *unsorted_head)
  	    });
  	}
 -	head->next = *cursor;
 -	*cursor = head;
 +	unsorted_head->next = *cursor;
 +	*cursor = unsorted_head;
 +	unsorted_head = next;
 +    } while (unsorted_head != NULL);
 -	head = next;
 -    }
      return sorted_head;
  }
  /* Test if the edges on the active list can be safely advanced by a
   * full row without intersections or any edges ending. */
  inline static int
 -active_list_can_step_full_row(
 -    struct active_list *active)
 +active_list_can_step_full_row (struct active_list *active,
 +			       grid_scaled_x_t     xmin)
  {
 +    const struct edge *e;
 +    grid_scaled_x_t prev_x = INT_MIN;
 +
      /* Recomputes the minimum height of all edges on the active
       * list if we have been dropping edges. */
      if (active->min_height <= 0) {
 -	struct edge *e = active->head;
  	int min_height = INT_MAX;
 +	e = active->head;
  	while (NULL != e) {
  	    if (e->height_left < min_height)
  		min_height = e->height_left;
@@ -1225,27 +1280,38 @@ active_list_can_step_full_row(
  	active->min_height = min_height;
      }
 -    /* Check for intersections only if no edges end during the next
 -     * row. */
 -    if (active->min_height >= GRID_Y) {
 -	grid_scaled_x_t prev_x = INT_MIN;
 -	struct edge *e = active->head;
 -	while (NULL != e) {
 -	    struct quorem x = e->x;
 +    if (active->min_height < GRID_Y)
 +	return 0;
 +    /* Check for intersections as no edges end during the next row. */
 +    e = active->head;
 +    while (NULL != e) {
 +	struct quorem x = e->x;
 +
 +	if (! e->vertical) {
  	    x.quo += e->dxdy_full.quo;
  	    x.rem += e->dxdy_full.rem;
  	    if (x.rem >= 0)
  		++x.quo;
 +	}
 -	    if (x.quo <= prev_x)
 +	/* There's may be an intersection if the edge sort order might
 +	 * change. */
 +	if (x.quo <= prev_x) {
 +	    /* Ignore intersections to the left of the clip extents.
 +	     * This assumes that all vertical edges on or at the left
 +	     * side of the clip rectangle have been shifted slightly
 +	     * to the left in polygon_add_edge(). */
 +	    if (prev_x >= xmin || x.quo >= xmin || e->x.quo >= xmin)
  		return 0;
 +	}
 +	else {
  	    prev_x = x.quo;
 -	    e = e->next;
  	}
 -	return 1;
 +	e = e->next;
      }
 -    return 0;
 +
 +    return 1;
  }
  /* Merges edges on the given subpixel row from the polygon to the
@@ -1261,7 +1327,7 @@ active_list_merge_edges_from_polygon(
      unsigned ix = EDGE_Y_BUCKET_INDEX(y, polygon->ymin);
      int min_height = active->min_height;
      struct edge *subrow_edges = NULL;
 -    struct edge **ptail = &polygon->y_buckets[ix];
 +    struct edge **ptail = &polygon->y_buckets[ix].edges;
      while (1) {
  	struct edge *tail = *ptail;
@@ -1277,8 +1343,10 @@ active_list_merge_edges_from_polygon(
  	    ptail = &tail->next;
  	}
      }
 -    active->head = merge_unsorted_edges(active->head, subrow_edges);
 -    active->min_height = min_height;
 +    if (subrow_edges) {
 +	active->head = merge_unsorted_edges(active->head, subrow_edges);
 +	active->min_height = min_height;
 +    }
  }
  /* Advance the edges on the active list by one subsample row by
@@ -1439,11 +1507,13 @@ apply_nonzero_fill_rule_and_step_edges (struct active_list *active,
  		}
  	    }
 -	    right_edge->x.quo += right_edge->dxdy_full.quo;
 -	    right_edge->x.rem += right_edge->dxdy_full.rem;
 -	    if (right_edge->x.rem >= 0) {
 -		++right_edge->x.quo;
 -		right_edge->x.rem -= right_edge->dy;
 +	    if (! right_edge->vertical) {
 +		right_edge->x.quo += right_edge->dxdy_full.quo;
 +		right_edge->x.rem += right_edge->dxdy_full.rem;
 +		if (right_edge->x.rem >= 0) {
 +		    ++right_edge->x.quo;
 +		    right_edge->x.rem -= right_edge->dy;
 +		}
  	    }
  	}
@@ -1472,6 +1542,7 @@ apply_evenodd_fill_rule_and_step_edges (struct active_list *active,
      left_edge = *cursor;
      while (NULL != left_edge) {
  	struct edge *right_edge;
 +	int winding = left_edge->dir;
  	left_edge->height_left -= GRID_Y;
  	if (left_edge->height_left)
@@ -1490,17 +1561,22 @@ apply_evenodd_fill_rule_and_step_edges (struct active_list *active,
  	    else
  		*cursor = right_edge->next;
 +	    winding += right_edge->dir;
 +	    if ((winding & 1) == 0) {
  	    if (right_edge->next == NULL ||
  		right_edge->next->x.quo != right_edge->x.quo)
  	    {
  		break;
  	    }
 +	    }
 -	    right_edge->x.quo += right_edge->dxdy_full.quo;
 -	    right_edge->x.rem += right_edge->dxdy_full.rem;
 -	    if (right_edge->x.rem >= 0) {
 -		++right_edge->x.quo;
 -		right_edge->x.rem -= right_edge->dy;
 +	    if (! right_edge->vertical) {
 +		right_edge->x.quo += right_edge->dxdy_full.quo;
 +		right_edge->x.rem += right_edge->dxdy_full.rem;
 +		if (right_edge->x.rem >= 0) {
 +		    ++right_edge->x.quo;
 +		    right_edge->x.rem -= right_edge->dy;
 +		}
  	    }
  	}
@@ -1537,8 +1613,14 @@ blit_span(
      }
  }
 -#define GLITTER_BLIT_COVERAGES(coverages, y, xmin, xmax) \
 -	blit_cells(coverages, raster_pixels + (y)*raster_stride, xmin, xmax)
 +#define GLITTER_BLIT_COVERAGES(coverages, y, height, xmin, xmax) \
 +    do { \
 +	int __y = y; \
 +	int __h = height; \
 +	do { \
 +	    blit_cells(coverages, raster_pixels + (__y)*raster_stride, xmin, xmax); \
 +	} while (--__h); \
 +    } while (0)
  static void
  blit_cells(
@@ -1597,7 +1679,6 @@ static void
  _glitter_scan_converter_fini(glitter_scan_converter_t *converter)
  {
      polygon_fini(converter->polygon);
 -    active_list_fini(converter->active);
      cell_list_fini(converter->coverages);
      converter->xmin=0;
      converter->ymin=0;
@@ -1641,7 +1722,7 @@ glitter_scan_converter_reset(
      active_list_reset(converter->active);
      cell_list_reset(converter->coverages);
 -    status = polygon_reset(converter->polygon, ymin, ymax);
 +    status = polygon_reset(converter->polygon, xmin, xmax, ymin, ymax);
      if (status)
  	return status;
@@ -1711,19 +1792,48 @@ glitter_scan_converter_add_edge (glitter_scan_converter_t *converter,
  #endif
  #ifndef GLITTER_BLIT_COVERAGES_EMPTY
 -# define GLITTER_BLIT_COVERAGES_EMPTY(y, xmin, xmax)
 +# define GLITTER_BLIT_COVERAGES_EMPTY(y0, y1, xmin, xmax)
  #endif
 +static cairo_bool_t
 +active_list_is_vertical (struct active_list *active)
 +{
 +    struct edge *e;
 +
 +    for (e = active->head; e != NULL; e = e->next) {
 +	if (! e->vertical)
 +	    return FALSE;
 +    }
 +
 +    return TRUE;
 +}
 +
 +static void
 +step_edges (struct active_list *active, int count)
 +{
 +    struct edge **cursor = &active->head;
 +    struct edge *edge;
 +
 +    for (edge = *cursor; edge != NULL; edge = *cursor) {
 +	edge->height_left -= GRID_Y * count;
 +	if (edge->height_left)
 +	    cursor = &edge->next;
 +	else
 +	    *cursor = edge->next;
 +    }
 +}
 +
  I glitter_status_t
  glitter_scan_converter_render(
      glitter_scan_converter_t *converter,
      int nonzero_fill,
      GLITTER_BLIT_COVERAGES_ARGS)
  {
 -    int i;
 +    int i, j;
      int ymax_i = converter->ymax / GRID_Y;
      int ymin_i = converter->ymin / GRID_Y;
      int xmin_i, xmax_i;
 +    grid_scaled_x_t xmin = converter->xmin;
      int h = ymax_i - ymin_i;
      struct polygon *polygon = converter->polygon;
      struct cell_list *coverages = converter->coverages;
@@ -1738,22 +1848,28 @@ glitter_scan_converter_render(
      GLITTER_BLIT_COVERAGES_BEGIN;
      /* Render each pixel row. */
 -    for (i=0; i<h; i++) {
 +    for (i = 0; i < h; i = j) {
  	int do_full_step = 0;
  	glitter_status_t status = 0;
 +	j = i + 1;
 +
  	/* Determine if we can ignore this row or use the full pixel
  	 * stepper. */
 -	if (GRID_Y == EDGE_Y_BUCKET_HEIGHT && ! polygon->y_buckets[i]) {
 +	if (polygon->y_buckets[i].edges == NULL) {
  	    if (! active->head) {
 -		GLITTER_BLIT_COVERAGES_EMPTY (i+ymin_i, xmin_i, xmax_i);
 +		for (; j < h && ! polygon->y_buckets[j].edges; j++)
 +		    ;
 +		GLITTER_BLIT_COVERAGES_EMPTY (i+ymin_i, j-i, xmin_i, xmax_i);
  		continue;
  	    }
 -
 -	    do_full_step = active_list_can_step_full_row (active);
 +	    do_full_step = active_list_can_step_full_row (active, xmin);
 +	}
 +	else if (! polygon->y_buckets[i].have_inside_edges) {
 +	    grid_scaled_y_t y = (i+ymin_i)*GRID_Y;
 +	    active_list_merge_edges_from_polygon (active, y, polygon);
 +	    do_full_step = active_list_can_step_full_row (active, xmin);
  	}
 -
 -	cell_list_reset (coverages);
  	if (do_full_step) {
  	    /* Step by a full pixel row's worth. */
@@ -1764,8 +1880,20 @@ glitter_scan_converter_render(
  		status = apply_evenodd_fill_rule_and_step_edges (active,
  								 coverages);
  	    }
 +
 +	    if (active_list_is_vertical (active)) {
 +		while (j < h &&
 +		       polygon->y_buckets[j].edges == NULL &&
 +		       active->min_height >= 2*GRID_Y)
 +		{
 +		    active->min_height -= GRID_Y;
 +		    j++;
 +		}
 +		if (j != i + 1)
 +		    step_edges (active, j - (i + 1));
 +	    }
  	} else {
 -	    /* Subsample this row. */
 +	    /* Supersample this row. */
  	    grid_scaled_y_t suby;
  	    for (suby = 0; suby < GRID_Y; suby++) {
  		grid_scaled_y_t y = (i+ymin_i)*GRID_Y + suby;
@@ -1787,13 +1915,13 @@ glitter_scan_converter_render(
  	if (unlikely (status))
  	    return status;
 -	GLITTER_BLIT_COVERAGES(coverages, i+ymin_i, xmin_i, xmax_i);
 +	GLITTER_BLIT_COVERAGES(coverages, i+ymin_i, j-i, xmin_i, xmax_i);
 +	cell_list_reset (coverages);
 -	if (! active->head) {
 +	if (! active->head)
  	    active->min_height = INT_MAX;
 -	} else {
 +	else
  	    active->min_height -= GRID_Y;
 -	}
      }
      /* Clean up the coverage blitter. */
@@ -1807,21 +1935,20 @@ glitter_scan_converter_render(
   * scan converter subclass. */
  static glitter_status_t
 -blit_with_span_renderer(
 -    struct cell_list *cells,
 -    cairo_span_renderer_t *renderer,
 -    struct pool *span_pool,
 -    int y,
 -    int xmin,
 -    int xmax)
 +blit_with_span_renderer (struct cell_list *cells,
 +			 cairo_span_renderer_t *renderer,
 +			 struct pool *span_pool,
 +			 int y, int height,
 +			 int xmin, int xmax)
  {
      struct cell *cell = cells->head;
      int prev_x = xmin;
      int cover = 0;
      cairo_half_open_span_t *spans;
      unsigned num_spans;
 +
      if (cell == NULL)
 -	return CAIRO_STATUS_SUCCESS;
 +	return blit_empty_with_span_renderer (renderer, y, height);
      /* Skip cells to the left of the clip region. */
      while (cell != NULL && cell->x < xmin) {
@@ -1833,12 +1960,12 @@ blit_with_span_renderer(
      /* Count number of cells remaining. */
      {
  	struct cell *next = cell;
 -	num_spans = 0;
 -	while (next) {
 +	num_spans = 1;
 +	while (next != NULL) {
  	    next = next->next;
  	    ++num_spans;
  	}
 -	num_spans = 2*num_spans + 1;
 +	num_spans = 2*num_spans;
      }
      /* Allocate enough spans for the row. */
@@ -1853,6 +1980,7 @@ blit_with_span_renderer(
      for (; cell != NULL; cell = cell->next) {
  	int x = cell->x;
  	int area;
 +
  	if (x >= xmax)
  	    break;
@@ -1872,20 +2000,26 @@ blit_with_span_renderer(
  	prev_x = x+1;
      }
 -    if (prev_x < xmax) {
 +    if (prev_x <= xmax) {
  	spans[num_spans].x = prev_x;
  	spans[num_spans].coverage = GRID_AREA_TO_ALPHA (cover);
  	++num_spans;
      }
 +    if (prev_x < xmax && cover) {
 +	spans[num_spans].x = xmax;
 +	spans[num_spans].coverage = 0;
 +	++num_spans;
 +    }
 +
      /* Dump them into the renderer. */
 -    return renderer->render_row (renderer, y, spans, num_spans);
 +    return renderer->render_rows (renderer, y, height, spans, num_spans);
  }
  static glitter_status_t
 -blit_empty_with_span_renderer (cairo_span_renderer_t *renderer, int y)
 +blit_empty_with_span_renderer (cairo_span_renderer_t *renderer, int y, int height)
  {
 -    return renderer->render_row (renderer, y, NULL, 0);
 +    return renderer->render_rows (renderer, y, height, NULL, 0);
  }
  struct _cairo_tor_scan_converter {
 diff --git a/src/cairo-win32-surface.c b/src/cairo-win32-surface.c
 index 82d1cf5..d4575a3 100644
 --- a/src/cairo-win32-surface.c
 +++ b/src/cairo-win32-surface.c
@@ -1954,6 +1954,9 @@ typedef struct _cairo_win32_surface_span_renderer {
      const cairo_pattern_t *pattern;
      cairo_antialias_t antialias;
 +    uint8_t *mask_data;
 +    uint32_t mask_stride;
 +
      cairo_image_surface_t *mask;
      cairo_win32_surface_t *dst;
      cairo_region_t *clip_region;
@@ -1962,14 +1965,16 @@ typedef struct _cairo_win32_surface_span_renderer {
  } cairo_win32_surface_span_renderer_t;
  static cairo_status_t
 -_cairo_win32_surface_span_renderer_render_row (
 +_cairo_win32_surface_span_renderer_render_rows (
      void				*abstract_renderer,
      int					 y,
 +    int					 height,
      const cairo_half_open_span_t	*spans,
      unsigned				 num_spans)
  {
      cairo_win32_surface_span_renderer_t *renderer = abstract_renderer;
 -    _cairo_image_surface_span_render_row (y, spans, num_spans, renderer->mask, &renderer->composite_rectangles);
 +    while (height--)
 +	_cairo_image_surface_span_render_row (y++, spans, num_spans, renderer->mask_data, renderer->mask_stride);
      return CAIRO_STATUS_SUCCESS;
  }
@@ -2066,8 +2071,7 @@ _cairo_win32_surface_create_span_renderer (cairo_operator_t	 op,
      renderer->base.destroy = _cairo_win32_surface_span_renderer_destroy;
      renderer->base.finish = _cairo_win32_surface_span_renderer_finish;
 -    renderer->base.render_row =
 -	_cairo_win32_surface_span_renderer_render_row;
 +    renderer->base.render_rows = _cairo_win32_surface_span_renderer_render_rows;
      renderer->op = op;
      renderer->pattern = pattern;
      renderer->antialias = antialias;
@@ -2088,6 +2092,9 @@ _cairo_win32_surface_create_span_renderer (cairo_operator_t	 op,
  	_cairo_win32_surface_span_renderer_destroy (renderer);
  	return _cairo_span_renderer_create_in_error (status);
      }
 +
 +    renderer->mask_data = renderer->mask->data - rects->mask.x - rects->mask.y * renderer->mask->stride;
 +    renderer->mask_stride = renderer->mask->stride;
      return &renderer->base;
  }
 diff --git a/src/cairo-xlib-display.c b/src/cairo-xlib-display.c
 index a7a40b8..566d9fb 100644
 --- a/src/cairo-xlib-display.c
 +++ b/src/cairo-xlib-display.c
@@ -407,6 +407,10 @@ _cairo_xlib_display_get (Display *dpy,
  	display->buggy_pad_reflect = TRUE;
      }
 +    /* gradients don't seem to work */
 +    display->buggy_gradients = TRUE;
 +
 +
      /* XXX workaround; see https://bugzilla.mozilla.org/show_bug.cgi?id=413583 */
      /* If buggy_repeat_force == -1, then initialize.
       *    - set to -2, meaning "nothing was specified", and we trust the above detection.
 diff --git a/src/cairoint.h b/src/cairoint.h
 index 58850ab..1cdf6ff 100644
 --- a/src/cairoint.h
 +++ b/src/cairoint.h
@@ -2257,8 +2257,8 @@ cairo_private void
  _cairo_image_surface_span_render_row (int				 y,
  				      const cairo_half_open_span_t	 *spans,
  				      unsigned				 num_spans,
 -				      cairo_image_surface_t              *mask,
 -				      const cairo_composite_rectangles_t *rects);
 +				      uint8_t				*data,
 +				      uint32_t				 stride);
  cairo_private cairo_image_transparency_t
  _cairo_image_analyze_transparency (cairo_image_surface_t      *image);

The Tor Browser / annotate

gfx/cairo/clip-invariant.patch@b8a032363ba2 (annotated)

gfx/cairo/clip-invariant.patch