Attachment 129392 Details for Bug 99705 – Suggested patch to paint line ends manually

[patch] Suggested patch to paint line ends manually

glamor-Paint-first-and-last-pixel-of-lines.patch (text/plain), 5.37 KB, created by Max Staudt on 2017-02-07 15:23:00 UTC

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Creator: Max Staudt

Created: 2017-02-07 15:23:00 UTC

Size: 5.37 KB

patch

obsolete

>From b2bed1b6f452e0592161a4220543ca952549a24e Mon Sep 17 00:00:00 2001
>From: Max Staudt <mstaudt@suse.de>
>Date: Tue, 7 Feb 2017 13:47:35 +0100
>Subject: [PATCH] glamor: Paint first and last pixel of lines
>
>OpenGL implementations are allowed to be imprecise in drawing line caps.
>This patch expands on the original workaround in dc9fa908.
>
>References: fdo#99705 boo#1021803
>Signed-off-by: Max Staudt <mstaudt@suse.de>
>---
> glamor/glamor_lines.c | 21 +++++++++------------
> glamor/glamor_segs.c  | 43 ++++++++++++++++++++++++-------------------
> 2 files changed, 33 insertions(+), 31 deletions(-)
>
>diff --git a/glamor/glamor_lines.c b/glamor/glamor_lines.c
>index ca3cccf..47f8ed2 100644
>--- a/glamor/glamor_lines.c
>+++ b/glamor/glamor_lines.c
>@@ -45,7 +45,6 @@ glamor_poly_lines_gl(DrawablePtr drawable, GCPtr gc,
>     DDXPointPtr v;
>     char *vbo_offset;
>     int box_x, box_y;
>-    int add_last;
> 
>     pixmap_priv = glamor_get_pixmap_private(pixmap);
>     if (!GLAMOR_PIXMAP_PRIV_HAS_FBO(pixmap_priv))
>@@ -57,10 +56,6 @@ glamor_poly_lines_gl(DrawablePtr drawable, GCPtr gc,
>     if (gc->lineStyle != LineSolid)
>         goto bail;
> 
>-    add_last = 0;
>-    if (gc->capStyle != CapNotLast)
>-        add_last = 1;
>-
>     if (n < 2)
>         return TRUE;
> 
>@@ -76,7 +71,7 @@ glamor_poly_lines_gl(DrawablePtr drawable, GCPtr gc,
>     /* Set up the vertex buffers for the points */
> 
>     v = glamor_get_vbo_space(drawable->pScreen,
>-                             (n + add_last) * sizeof (DDXPointRec),
>+                             n * sizeof (DDXPointRec),
>                              &vbo_offset);
> 
>     glEnableVertexAttribArray(GLAMOR_VERTEX_POS);
>@@ -96,11 +91,6 @@ glamor_poly_lines_gl(DrawablePtr drawable, GCPtr gc,
>         memcpy(v, points, n * sizeof (DDXPointRec));
>     }
> 
>-    if (add_last) {
>-        v[n].x = v[n-1].x + 1;
>-        v[n].y = v[n-1].y;
>-    }
>-
>     glamor_put_vbo_space(screen);
> 
>     glEnable(GL_SCISSOR_TEST);
>@@ -118,7 +108,14 @@ glamor_poly_lines_gl(DrawablePtr drawable, GCPtr gc,
>                       box->x2 - box->x1,
>                       box->y2 - box->y1);
>             box++;
>-            glDrawArrays(GL_LINE_STRIP, 0, n + add_last);
>+            glDrawArrays(GL_LINE_STRIP, 0, n);
>+
>+            /* Draw the first and last pixels, as implementations are
>+             * allowed to be inaccurate there. */
>+            if (gc->capStyle == CapNotLast)
>+                glDrawArrays(GL_POINTS, 0, n-1);
>+            else
>+                glDrawArrays(GL_POINTS, 0, n);
>         }
>     }
> 
>diff --git a/glamor/glamor_segs.c b/glamor/glamor_segs.c
>index 0168d05..b571b10 100644
>--- a/glamor/glamor_segs.c
>+++ b/glamor/glamor_segs.c
>@@ -45,7 +45,6 @@ glamor_poly_segment_gl(DrawablePtr drawable, GCPtr gc,
>     xSegment *v;
>     char *vbo_offset;
>     int box_x, box_y;
>-    int add_last;
> 
>     pixmap_priv = glamor_get_pixmap_private(pixmap);
>     if (!GLAMOR_PIXMAP_PRIV_HAS_FBO(pixmap_priv))
>@@ -57,10 +56,6 @@ glamor_poly_segment_gl(DrawablePtr drawable, GCPtr gc,
>     if (gc->lineStyle != LineSolid)
>         goto bail;
> 
>-    add_last = 0;
>-    if (gc->capStyle != CapNotLast)
>-        add_last = 1;
>-
>     glamor_make_current(glamor_priv);
> 
>     prog = glamor_use_program_fill(pixmap, gc,
>@@ -71,27 +66,25 @@ glamor_poly_segment_gl(DrawablePtr drawable, GCPtr gc,
>         goto bail_ctx;
> 
>     /* Set up the vertex buffers for the points */
>-
>+    /* We need 1.5 times the space in case of CapNotLast,
>+     * so let's just always allocate 2 times the space. */
>     v = glamor_get_vbo_space(drawable->pScreen,
>-                             (nseg << add_last) * sizeof (xSegment),
>+                             nseg * sizeof (xSegment) * 2,
>                              &vbo_offset);
> 
>     glEnableVertexAttribArray(GLAMOR_VERTEX_POS);
>     glVertexAttribPointer(GLAMOR_VERTEX_POS, 2, GL_SHORT, GL_FALSE,
>                           sizeof(DDXPointRec), vbo_offset);
> 
>-    if (add_last) {
>-        int i, j;
>-        for (i = 0, j=0; i < nseg; i++) {
>-            v[j++] = segs[i];
>-            v[j].x1 = segs[i].x2;
>-            v[j].y1 = segs[i].y2;
>-            v[j].x2 = segs[i].x2+1;
>-            v[j].y2 = segs[i].y2;
>-            j++;
>+    memcpy(v, segs, nseg * sizeof (xSegment));
>+
>+    /* In case of CapNotLast, copy the line starting points for later */
>+    if (gc->capStyle != CapNotLast) {
>+        int i;
>+        for (i = 0; i < nseg; i++) {
>+            v[2*nseg + i] = v[2*i];
>         }
>-    } else
>-        memcpy(v, segs, nseg * sizeof (xSegment));
>+    }
> 
>     glamor_put_vbo_space(screen);
> 
>@@ -110,7 +103,19 @@ glamor_poly_segment_gl(DrawablePtr drawable, GCPtr gc,
>                       box->x2 - box->x1,
>                       box->y2 - box->y1);
>             box++;
>-            glDrawArrays(GL_LINES, 0, nseg << (1 + add_last));
>+            glDrawArrays(GL_LINES, 0, nseg * 2);
>+
>+            /* Draw the first and last pixel of each line, as OpenGL
>+             * implementations are allowed to be inaccurate there.
>+             * Since we're drawing all line ends, we can just reuse
>+             * the array of all line starts and ends. */
>+            if (gc->capStyle != CapNotLast) {
>+                glDrawArrays(GL_POINTS, 0, nseg * 2);
>+            } else {
>+                /* With CapNotLast, we only want to draw the starting points.
>+                 * That's why we copied them earlier. */
>+                glDrawArrays(GL_POINTS, nseg, nseg);
>+            }
>         }
>     }
> 
>-- 
>2.10.2
>

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Attachments on bug 99705: 129387 | 129388 | 129390 | 129391 | 129392

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