mesa/virgl: Fix off-by-one and copy-paste error in multisample position evaluation

Converting from a switch statement that would not allow intermediate sample counts
to use an if-else chain went a bit wrong, so that in some cases the range that
should be inclusive was exclusive and the line for 16 samples was copies wrongly.

v2: elaborate commit message.

Fixes: 91f48cdfe5c817158c533a8f67c60e9aabbe4479
       virgl: Add support for glGetMultisample
Signed-off-by: Gert Wollny <gert.wollny@collabora.com>
Reviewed-by: Erik Faye-Lund <erik.faye-lund@collabora.com> (v1)

diff --git a/src/gallium/drivers/virgl/virgl_context.c b/src/gallium/drivers/virgl/virgl_context.c
index d985bf906fbe70fb2f8d93574134900e298b71cb..f5e3832d99f2c04461612e0d8b506ef6b6fa3c0b 100644 (file)
--- a/src/gallium/drivers/virgl/virgl_context.c
+++ b/src/gallium/drivers/virgl/virgl_context.c
@@ -943,11 +943,11 @@ static void virgl_get_sample_position(struct pipe_context *ctx,
       return;
    } else if (sample_count == 2) {
       bits = vs->caps.caps.v2.msaa_sample_positions[0] >> (8 * index);
-   } else if (sample_count < 4) {
+   } else if (sample_count <= 4) {
       bits = vs->caps.caps.v2.msaa_sample_positions[1] >> (8 * index);
-   } else if (sample_count < 8) {
+   } else if (sample_count <= 8) {
       bits = vs->caps.caps.v2.msaa_sample_positions[2 + (index >> 2)] >> (8 * (index & 3));
-   } else if (sample_count < 8) {
+   } else if (sample_count <= 16) {
       bits = vs->caps.caps.v2.msaa_sample_positions[4 + (index >> 2)] >> (8 * (index & 3));
    }
    out_value[0] = ((bits >> 4) & 0xf) / 16.0f;