Attachment 107189 Details for Bug 84396 – Analytical coverage inside the pixel, not sample points

[patch] Analytical coverage inside the pixel, not sample points

0001-tor-Perform-analytic-coverage-over-the-pixel-not-sam.patch (text/plain), 4.39 KB, created by Chris Wilson on 2014-10-01 13:49:52 UTC

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Creator: Chris Wilson

Created: 2014-10-01 13:49:52 UTC

Size: 4.39 KB

patch

obsolete

>From cea27dc5c6a7d9a6b2dea44e28c3b28b0fc05017 Mon Sep 17 00:00:00 2001
>From: Chris Wilson <chris@chris-wilson.co.uk>
>Date: Wed, 1 Oct 2014 12:59:29 +0100
>Subject: [PATCH] tor: Perform analytic coverage over the pixel not sample
> points
>
>Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
>---
> src/cairo-tor-scan-converter.c | 66 ++++++++++++++++++++++++++++++------------
> 1 file changed, 48 insertions(+), 18 deletions(-)
>
>diff --git a/src/cairo-tor-scan-converter.c b/src/cairo-tor-scan-converter.c
>index 1c89798..c3728ef 100644
>--- a/src/cairo-tor-scan-converter.c
>+++ b/src/cairo-tor-scan-converter.c
>@@ -761,7 +761,6 @@ inline static void full_step (struct edge *e)
> 	++e->x.quo;
> 	e->x.rem -= e->dy;
>     }
>-    assert (e->x.rem >= 0 && e->x.rem < e->dy);
> 
>     e->cell = e->x.quo + (e->x.rem >= e->dy/2);
> }
>@@ -789,12 +788,40 @@ cell_list_render_edge(struct cell_list *cells,
> 		      struct edge *edge,
> 		      int sign)
> {
>+    struct quorem x1, x2;
>     grid_scaled_x_t fx1, fx2;
>     int ix1, ix2;
> 
>-    GRID_X_TO_INT_FRAC(edge->cell, ix1, fx1);
>+    x1 = edge->x;
>     full_step (edge);
>-    GRID_X_TO_INT_FRAC(edge->cell, ix2, fx2);
>+    x2 = edge->x;
>+
>+    if (edge->dy) {
>+	x1.quo -= edge->dxdy.quo / 2;
>+	x1.rem -= edge->dxdy.rem / 2;
>+	if (x1.rem < 0) {
>+	    --x1.quo;
>+	    x1.rem += edge->dy;
>+	} else if (x1.rem >= edge->dy) {
>+	    ++x1.quo;
>+	    x1.rem -= edge->dy;
>+	}
>+
>+	x2.quo -= edge->dxdy.quo / 2;
>+	x2.rem -= edge->dxdy.rem / 2;
>+	if (x2.rem < 0) {
>+	    --x2.quo;
>+	    x2.rem += edge->dy;
>+	} else if (x2.rem >= edge->dy) {
>+	    ++x2.quo;
>+	    x2.rem -= edge->dy;
>+	}
>+    }
>+
>+    GRID_X_TO_INT_FRAC(x1.quo, ix1, fx1);
>+    GRID_X_TO_INT_FRAC(x2.quo, ix2, fx2);
>+
>+    cell_list_maybe_rewind(cells, MIN(ix1, ix2));
> 
>     /* Edge is entirely within a column? */
>     if (ix1 == ix2) {
>@@ -808,6 +835,7 @@ cell_list_render_edge(struct cell_list *cells,
> 
>     /* Orient the edge left-to-right. */
>     if (ix2 < ix1) {
>+	struct quorem tx;
> 	int t;
> 
> 	t = ix1;
>@@ -817,6 +845,10 @@ cell_list_render_edge(struct cell_list *cells,
> 	t = fx1;
> 	fx1 = fx2;
> 	fx2 = t;
>+
>+	tx = x1;
>+	x1 = x2;
>+	x2 = tx;
>     }
> 
>     /* Add coverage for all pixels [ix1,ix2] on this row crossed
>@@ -824,14 +856,17 @@ cell_list_render_edge(struct cell_list *cells,
>     {
> 	struct cell_pair pair;
> 	struct quorem y;
>-	int32_t dx;
>+	int64_t tmp, dx;
> 	int y_last;
> 
>-	dx = (ix2 - ix1) * GRID_X + (fx2 - fx1);
>-	assert (dx > 0);
>+	dx = (x2.quo - x1.quo) * edge->dy + (x2.rem - x1.rem);
> 
>-	y.quo = (GRID_X - fx1) * GRID_Y / dx;
>-	y.rem = (GRID_X - fx1) * GRID_Y % dx;
>+	tmp = (ix1 + 1) * GRID_X * edge->dy;
>+	tmp -= x1.quo * edge->dy + x1.rem;
>+	tmp *= GRID_Y;
>+
>+	y.quo = tmp / dx;
>+	y.rem = tmp % dx;
> 
> 	/* When rendering a previous edge on the active list we may
> 	 * advance the cell list cursor past the leftmost pixel of the
>@@ -847,11 +882,7 @@ cell_list_render_edge(struct cell_list *cells,
> 	 *
> 	 * The left edge touches cells past the starting cell of the
> 	 * right edge.  Fortunately such cases are rare.
>-	 *
>-	 * The rewinding is never necessary if the current edge stays
>-	 * within a single column because we've checked before calling
>-	 * this function that the active list order won't change. */
>-	cell_list_maybe_rewind(cells, ix1);
>+	 */
> 
> 	pair = cell_list_find_pair(cells, ix1, ix1+1);
> 	pair.cell1->uncovered_area += sign*y.quo*(GRID_X + fx1);
>@@ -862,8 +893,8 @@ cell_list_render_edge(struct cell_list *cells,
> 	    struct cell *cell = pair.cell2;
> 	    struct quorem dydx_full;
> 
>-	    dydx_full.quo = GRID_Y * GRID_X / dx;
>-	    dydx_full.rem = GRID_Y * GRID_X % dx;
>+	    dydx_full.quo = GRID_Y * GRID_X * edge->dy / dx;
>+	    dydx_full.rem = GRID_Y * GRID_X * edge->dy % dx;
> 
> 	    ++ix1;
> 	    do {
>@@ -1207,7 +1238,6 @@ static void step (struct edge *edge)
> 	++edge->x.quo;
> 	edge->x.rem -= edge->dy;
>     }
>-    assert (edge->x.rem >= 0 && edge->x.rem < edge->dy);
> 
>     edge->cell = edge->x.quo + (edge->x.rem >= edge->dy/2);
> }
>@@ -1453,7 +1483,8 @@ polygon_add_edge (struct polygon *polygon,
> 
>     if (p2->x == p1->x) {
> 	e->cell = p1->x;
>-	e->x.quo = e->x.rem = 0;
>+	e->x.quo = p1->x;
>+	e->x.rem = 0;
> 	e->dxdy.quo = e->dxdy.rem = 0;
> 	e->dxdy_full.quo = e->dxdy_full.rem = 0;
> 	e->dy = 0;
>@@ -1487,7 +1518,6 @@ polygon_add_edge (struct polygon *polygon,
> 		e->x.quo++;
> 		e->x.rem -= Ey;
> 	}
>-	assert (e->x.rem >= 0 && e->x.rem < Ey);
> 
> 	if (e->height_left >= GRID_Y) {
> 	    tmp = Ex * (2 * GRID_Y << GLITTER_INPUT_BITS);
>-- 
>2.1.1
>

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Attachments on bug 84396: 106961 | 106989 | 107095 | 107101 | 107103 | 107104 | 107186 | 107189 | 107344

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