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-rw-r--r--src/mesa/drivers/dri/i965/gen6_sf_state.c22
1 files changed, 19 insertions, 3 deletions
diff --git a/src/mesa/drivers/dri/i965/gen6_sf_state.c b/src/mesa/drivers/dri/i965/gen6_sf_state.c
index ea5c47a895f..e445ce25600 100644
--- a/src/mesa/drivers/dri/i965/gen6_sf_state.c
+++ b/src/mesa/drivers/dri/i965/gen6_sf_state.c
@@ -367,9 +367,25 @@ upload_sf_state(struct brw_context *brw)
float line_width =
roundf(CLAMP(ctx->Line.Width, 0.0, ctx->Const.MaxLineWidth));
uint32_t line_width_u3_7 = U_FIXED(line_width, 7);
- /* TODO: line width of 0 is not allowed when MSAA enabled */
- if (line_width_u3_7 == 0)
- line_width_u3_7 = 1;
+
+ /* Line width of 0 is not allowed when MSAA enabled */
+ if (ctx->Multisample._Enabled) {
+ if (line_width_u3_7 == 0)
+ line_width_u3_7 = 1;
+ } else if (ctx->Line.SmoothFlag && ctx->Line.Width < 1.5) {
+ /* For 1 pixel line thickness or less, the general
+ * anti-aliasing algorithm gives up, and a garbage line is
+ * generated. Setting a Line Width of 0.0 specifies the
+ * rasterization of the "thinnest" (one-pixel-wide),
+ * non-antialiased lines.
+ *
+ * Lines rendered with zero Line Width are rasterized using
+ * Grid Intersection Quantization rules as specified by
+ * bspec section 6.3.12.1 Zero-Width (Cosmetic) Line
+ * Rasterization.
+ */
+ line_width_u3_7 = 0;
+ }
dw3 |= line_width_u3_7 << GEN6_SF_LINE_WIDTH_SHIFT;
}
if (ctx->Line.SmoothFlag) {