[Mesa-dev] [PATCH] r600: Scale integer valued texture border colors to float (v2)

[Gert Wollny]

It seems the hardware always expects floating point border color values
[0,1] for unsigned, and [-1,1] for signed texture component, regardless
of pixel type, but the border colors are passed according to texture
component type. Hence, before submitting the border color, convert and
scale it these ranges accordingly.

This doesn't seem to work for textures with 32 bit integer components
though, here, it seems that the border color is always set to zero,
regardless of the BORDER_COLOR_TYPE state set in Q_TEX_SAMPLER_WORD0_0.

v2: Simplyfy logic as suggested by Roland Schneidegger

Fixes:
  dEQP-GLES31.functional.texture.border_clamp.formats.compressed*
  dEQP-GLES31.functional.texture.border_clamp.formats.r* (non 32 bit integer)
  dEQP-GLES31.functional.texture.border_clamp.per_axis_wrap_mode.texture_2d*
 and a number of piglits out of 
  piglit run gpu -t texture -t gather -t formats 

Signed-off-by: Gert Wollny <gw.fossdev at gmail.com>
---
 src/gallium/drivers/r600/evergreen_state.c | 45 +++++++++++++++++++++++++++++-
 1 file changed, 44 insertions(+), 1 deletion(-)

diff --git a/src/gallium/drivers/r600/evergreen_state.c b/src/gallium/drivers/r600/evergreen_state.c
index d100cfab1d..e7207a500b 100644
--- a/src/gallium/drivers/r600/evergreen_state.c
+++ b/src/gallium/drivers/r600/evergreen_state.c
@@ -2402,6 +2402,37 @@ static void evergreen_emit_cs_sampler_views(struct r600_context *rctx, struct r6
 	                             EG_FETCH_CONSTANTS_OFFSET_CS + R600_MAX_CONST_BUFFERS, RADEON_CP_PACKET3_COMPUTE_MODE);
 }
 
+static void evergreen_convert_border_color(union pipe_color_union *in,
+                                           union pipe_color_union *out,
+                                           enum pipe_format format)
+{
+	if (util_format_is_pure_integer(format) &&
+		 !util_format_is_depth_or_stencil(format)) {
+		const struct util_format_description *d = util_format_description(format);
+
+		for (int i = 0; i < d->nr_channels; ++i) {
+			int cs = d->channel[i].size;
+			if (d->channel[i].type == UTIL_FORMAT_TYPE_SIGNED)
+				out->f[i] = (double)(in->i[i]) / ((1ul << (cs - 1)) - 1 );
+			else if (d->channel[i].type == UTIL_FORMAT_TYPE_UNSIGNED)
+				out->f[i] = (double)(in->ui[i]) / ((1ul << cs) - 1 );
+			else
+				out->f[i] = 0;
+		}
+
+	} else {
+		switch (format) {
+      case PIPE_FORMAT_X24S8_UINT:
+      case PIPE_FORMAT_X32_S8X24_UINT:
+			out->f[0] = (double)(in->ui[0]) / 255.0;
+			out->f[1] = out->f[2] = out->f[3] = 0.0f;
+			break;
+		default:
+			memcpy(out->f, in->f, 4 * sizeof(float));
+		}
+	}
+}
+
 static void evergreen_emit_sampler_states(struct r600_context *rctx,
 				struct r600_textures_info *texinfo,
 				unsigned resource_id_base,
@@ -2410,6 +2441,8 @@ static void evergreen_emit_sampler_states(struct r600_context *rctx,
 {
 	struct radeon_cmdbuf *cs = rctx->b.gfx.cs;
 	uint32_t dirty_mask = texinfo->states.dirty_mask;
+	union pipe_color_union border_color = {{0,0,0,1}};
+	union pipe_color_union *border_color_ptr = &border_color;
 
 	while (dirty_mask) {
 		struct r600_pipe_sampler_state *rstate;
@@ -2418,6 +2451,16 @@ static void evergreen_emit_sampler_states(struct r600_context *rctx,
 		rstate = texinfo->states.states[i];
 		assert(rstate);
 
+		if (rstate->border_color_use) {
+			struct r600_pipe_sampler_view	*rview = texinfo->views.views[i];
+			if (rview) {
+				evergreen_convert_border_color(&rstate->border_color,
+				                               &border_color, rview->base.format);
+			} else {
+				border_color_ptr = &rstate->border_color;
+			}
+		}
+
 		radeon_emit(cs, PKT3(PKT3_SET_SAMPLER, 3, 0) | pkt_flags);
 		radeon_emit(cs, (resource_id_base + i) * 3);
 		radeon_emit_array(cs, rstate->tex_sampler_words, 3);
@@ -2425,7 +2468,7 @@ static void evergreen_emit_sampler_states(struct r600_context *rctx,
 		if (rstate->border_color_use) {
 			radeon_set_config_reg_seq(cs, border_index_reg, 5);
 			radeon_emit(cs, i);
-			radeon_emit_array(cs, rstate->border_color.ui, 4);
+			radeon_emit_array(cs, border_color_ptr->ui, 4);
 		}
 	}
 	texinfo->states.dirty_mask = 0;
-- 
2.16.4