From f2215809377234aa2073502587e1803c8952bea3 Mon Sep 17 00:00:00 2001 From: Brian Paul Date: Thu, 15 Oct 2015 22:57:08 -0600 Subject: [PATCH] vbo: convert display list GL_LINE_LOOP prims to GL_LINE_STRIP When a long GL_LINE_LOOP prim was split across primitives we drew stray lines. See previous commit for details. This patch converts GL_LINE_LOOP prims into GL_LINE_STRIP prims so that drivers don't have to worry about the _mesa_prim::begin/end flags. Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=81174 Reviewed-by: Jose Fonseca Acked-by: Sinclair Yeh --- src/mesa/vbo/vbo_save_api.c | 53 +++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 53 insertions(+) diff --git a/src/mesa/vbo/vbo_save_api.c b/src/mesa/vbo/vbo_save_api.c index 6688ba0..d49aa15 100644 --- a/src/mesa/vbo/vbo_save_api.c +++ b/src/mesa/vbo/vbo_save_api.c @@ -360,6 +360,51 @@ merge_prims(struct _mesa_prim *prim_list, *prim_count = prev_prim - prim_list + 1; } + +/** + * Convert GL_LINE_LOOP primitive into GL_LINE_STRIP so that drivers + * don't have to worry about handling the _mesa_prim::begin/end flags. + * See https://bugs.freedesktop.org/show_bug.cgi?id=81174 + */ +static void +convert_line_loop_to_strip(struct vbo_save_context *save, + struct vbo_save_vertex_list *node) +{ + struct _mesa_prim *prim = &node->prim[node->prim_count - 1]; + + assert(prim->mode == GL_LINE_LOOP); + + if (prim->end) { + /* Copy the 0th vertex to end of the buffer and extend the + * vertex count by one to finish the line loop. + */ + const GLuint sz = save->vertex_size; + /* 0th vertex: */ + const fi_type *src = save->buffer + prim->start * sz; + /* end of buffer: */ + fi_type *dst = save->buffer + (prim->start + prim->count) * sz; + + memcpy(dst, src, sz * sizeof(float)); + + prim->count++; + node->count++; + save->vert_count++; + save->buffer_ptr += sz; + save->vertex_store->used += sz; + } + + if (!prim->begin) { + /* Drawing the second or later section of a long line loop. + * Skip the 0th vertex. + */ + prim->start++; + prim->count--; + } + + prim->mode = GL_LINE_STRIP; +} + + /** * Insert the active immediate struct onto the display list currently * being built. @@ -441,6 +486,10 @@ _save_compile_vertex_list(struct gl_context *ctx) */ save->copied.nr = _save_copy_vertices(ctx, node, save->buffer); + if (node->prim[node->prim_count - 1].mode == GL_LINE_LOOP) { + convert_line_loop_to_strip(save, node); + } + merge_prims(node->prim, &node->prim_count); /* Deal with GL_COMPILE_AND_EXECUTE: @@ -482,6 +531,10 @@ _save_compile_vertex_list(struct gl_context *ctx) save->buffer_ptr = vbo_save_map_vertex_store(ctx, save->vertex_store); save->out_of_memory = save->buffer_ptr == NULL; } + else { + /* update buffer_ptr for next vertex */ + save->buffer_ptr = save->vertex_store->buffer + save->vertex_store->used; + } if (save->prim_store->used > VBO_SAVE_PRIM_SIZE - 6) { save->prim_store->refcount--; -- 2.7.4