diff options
Diffstat (limited to 'src/gallium/auxiliary/draw/draw_context.c')
| -rw-r--r-- | src/gallium/auxiliary/draw/draw_context.c | 24 |
1 files changed, 21 insertions, 3 deletions
diff --git a/src/gallium/auxiliary/draw/draw_context.c b/src/gallium/auxiliary/draw/draw_context.c index c28e78d33a3..6e5e4d64d11 100644 --- a/src/gallium/auxiliary/draw/draw_context.c +++ b/src/gallium/auxiliary/draw/draw_context.c @@ -244,14 +244,32 @@ draw_convert_wide_lines(struct draw_context *draw, boolean enable) /** - * The draw module may sometimes generate vertices with extra attributes - * (such as texcoords for AA lines). The driver can call this function - * to find those attributes. + * Ask the draw module for the location/slot of the given vertex attribute in + * a post-transformed vertex. + * + * With this function, drivers that use the draw module should have no reason + * to track the current vertex shader. + * + * Note that the draw module may sometimes generate vertices with extra + * attributes (such as texcoords for AA lines). The driver can call this + * function to find those attributes. + * + * Zero is returned if the attribute is not found since this is + * a don't care / undefined situtation. Returning -1 would be a bit more + * work for the drivers. */ int draw_find_vs_output(struct draw_context *draw, uint semantic_name, uint semantic_index) { + const struct pipe_shader_state *vs = &draw->vertex_shader->state; + uint i; + for (i = 0; i < vs->num_outputs; i++) { + if (vs->output_semantic_name[i] == semantic_name && + vs->output_semantic_index[i] == semantic_index) + return i; + } + /* XXX there may be more than one extra vertex attrib. * For example, simulated gl_FragCoord and gl_PointCoord. */ |