>From: Brian Paul <bri...@vmware.com> >Sent: Friday, October 16, 2015 2:25 PM >To: mesa-dev@lists.freedesktop.org >Cc: Charmaine Lee; Jose Fonseca; Sinclair Yeh >Subject: [PATCH 09/10] vbo: fix GL_LINE_LOOP stray line bug
>When long GL_LINE_LOOP primitives don't fit in one vertex buffer they >have to be split across buffers. The code to do this was basically correct >but drivers had to pay special attention to the _mesa_prim::begin,end flags >in order to draw the sections of the line loop properly. Apparently, the >only drivers to do this were those using the old 'tnl' module for software >vertex processing. >Now we convert the split pieces of GL_LINE_LOOP prims into GL_LINE_STRIP >primitives so that drivers don't have to worry about the special begin/end >flags. The only time a driver will get a GL_LINE_LOOP prim is when the >whole thing fits in one vertex buffer. >Most fixes bug 81174, but not completely. There's another bug somewhere >in the src/gallium/auxiliary/draw/ code. If the piglit lineloop test is >run with -count 4096, rendering is correct, but with -count 4097 there are >stray lines. 4096 is a magic number in the draw code (search for "4096"). >Also note that this does not fix long line loops in display lists. The >next patch fixes that. >Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=81174 >--- > src/mesa/vbo/vbo_context.h | 5 ++++- > src/mesa/vbo/vbo_exec_api.c | 38 +++++++++++++++++++++++++++++++++++++- > src/mesa/vbo/vbo_exec_draw.c | 12 ++++++++++++ > 3 files changed, 53 insertions(+), 2 deletions(-) >diff --git a/src/mesa/vbo/vbo_context.h b/src/mesa/vbo/vbo_context.h >index 1e85335..28f43b4 100644 >--- a/src/mesa/vbo/vbo_context.h >+++ b/src/mesa/vbo/vbo_context.h >@@ -205,7 +205,10 @@ vbo_get_default_vals_as_union(GLenum format) > static inline unsigned > vbo_compute_max_verts(const struct vbo_exec_context *exec) > { >- return (VBO_VERT_BUFFER_SIZE - exec->vtx.buffer_used) / >+ /* Subtract one so we're always sure to have room for an extra >+ * vertex for GL_LINE_LOOP -> GL_LINE_STRIP conversion. >+ */ >+ return (VBO_VERT_BUFFER_SIZE - exec->vtx.buffer_used - 1) / > (exec->vtx.vertex_size * sizeof(GLfloat)); Shouldn't this be (VBO_VERT_BUFFER_SIZE - exec->vtx.buffer_used) / (exec->vtx.vertex_size *sizeof(GLfloat)) - 1; -Charmaine _______________________________________________ mesa-dev mailing list mesa-dev@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/mesa-dev
