ilo: clean up sample patterns

Use signed int for sample positions and add helpers to access them.  Call them
patterns instead of positions.

5 files changed, 71 insertions, 68 deletions

diff --git a/src/gallium/drivers/ilo/ilo_builder_3d_bottom.h b/src/gallium/drivers/ilo/ilo_builder_3d_bottom.h
index a66ed0b7af9..f137232bcaa 100644
--- a/src/gallium/drivers/ilo/ilo_builder_3d_bottom.h
+++ b/src/gallium/drivers/ilo/ilo_builder_3d_bottom.h
@@ -524,8 +524,7 @@ gen7_3DSTATE_SAMPLER_STATE_POINTERS_PS(struct ilo_builder *builder,
 
 static inline void
 gen6_3DSTATE_MULTISAMPLE(struct ilo_builder *builder,
-                         int num_samples,
-                         const uint32_t *packed_sample_pos,
+                         int num_samples, const uint32_t *pattern,
                          bool pixel_location_center)
 {
    const uint8_t cmd_len = (ilo_dev_gen(builder->dev) >= ILO_GEN(7)) ? 4 : 3;
@@ -545,14 +544,14 @@ gen6_3DSTATE_MULTISAMPLE(struct ilo_builder *builder,
       break;
    case 4:
       dw1 |= GEN6_MULTISAMPLE_DW1_NUMSAMPLES_4;
-      dw2 = packed_sample_pos[0];
+      dw2 = pattern[0];
       dw3 = 0;
       break;
    case 8:
       assert(ilo_dev_gen(builder->dev) >= ILO_GEN(7));
       dw1 |= GEN7_MULTISAMPLE_DW1_NUMSAMPLES_8;
-      dw2 = packed_sample_pos[0];
-      dw3 = packed_sample_pos[1];
+      dw2 = pattern[0];
+      dw3 = pattern[1];
       break;
    default:
       assert(!"unsupported sample count");
diff --git a/src/gallium/drivers/ilo/ilo_render.c b/src/gallium/drivers/ilo/ilo_render.c
index 00b57b808ad..c48a50defb4 100644
--- a/src/gallium/drivers/ilo/ilo_render.c
+++ b/src/gallium/drivers/ilo/ilo_render.c
@@ -35,34 +35,47 @@
 #include "ilo_query.h"
 #include "ilo_render_gen.h"
 
-/* in U0.4 */
+/* in S1.3 */
 struct sample_position {
-   uint8_t x, y;
+   int8_t x, y;
 };
 
-/* \see gen6_get_sample_position() */
-static const struct sample_position sample_position_1x[1] = {
-   {  8,  8 },
+static const struct sample_position ilo_sample_pattern_1x[1] = {
+   {  0,  0 },
 };
 
-static const struct sample_position sample_position_4x[4] = {
-   {  6,  2 }, /* distance from the center is sqrt(40) */
-   { 14,  6 }, /* distance from the center is sqrt(40) */
-   {  2, 10 }, /* distance from the center is sqrt(40) */
-   { 10, 14 }, /* distance from the center is sqrt(40) */
+static const struct sample_position ilo_sample_pattern_4x[4] = {
+   { -2, -6 },
+   {  6, -2 },
+   { -6,  2 },
+   {  2,  6 },
 };
 
-static const struct sample_position sample_position_8x[8] = {
-   {  7,  9 }, /* distance from the center is sqrt(2) */
-   {  9, 13 }, /* distance from the center is sqrt(26) */
-   { 11,  3 }, /* distance from the center is sqrt(34) */
-   { 13, 11 }, /* distance from the center is sqrt(34) */
-   {  1,  7 }, /* distance from the center is sqrt(50) */
-   {  5,  1 }, /* distance from the center is sqrt(58) */
-   { 15,  5 }, /* distance from the center is sqrt(58) */
-   {  3, 15 }, /* distance from the center is sqrt(74) */
+/* \see brw_multisample_positions_8x */
+static const struct sample_position ilo_sample_pattern_8x[8] = {
+   { -1,  1 },
+   {  1,  5 },
+   {  3, -5 },
+   {  5,  3 },
+   { -7, -1 },
+   { -3, -7 },
+   {  7, -3 },
+   { -5,  7 },
 };
 
+static uint8_t
+pack_sample_position(const struct sample_position *pos)
+{
+   return (pos->x + 8) << 4 | (pos->y + 8);
+}
+
+static void
+get_sample_position(const struct sample_position *pos, float *x, float *y)
+{
+   *x = (float) (pos->x + 8) / 16.0f;
+   *y = (float) (pos->y + 8) / 16.0f;
+}
+
 struct ilo_render *
 ilo_render_create(struct ilo_builder *builder)
 {
@@ -84,23 +97,16 @@ ilo_render_create(struct ilo_builder *builder)
       return NULL;
    }
 
-   render->packed_sample_position_1x =
-      sample_position_1x[0].x << 4 |
-      sample_position_1x[0].y;
-
    /* pack into dwords */
+   render->sample_pattern_1x = pack_sample_position(ilo_sample_pattern_1x);
    for (i = 0; i < 4; i++) {
-      render->packed_sample_position_4x |=
-         sample_position_4x[i].x << (8 * i + 4) |
-         sample_position_4x[i].y << (8 * i);
-
-      render->packed_sample_position_8x[0] |=
-         sample_position_8x[i].x << (8 * i + 4) |
-         sample_position_8x[i].y << (8 * i);
+      render->sample_pattern_4x |=
+         pack_sample_position(&ilo_sample_pattern_4x[i]) << (8 * i);
 
-      render->packed_sample_position_8x[1] |=
-         sample_position_8x[4 + i].x << (8 * i + 4) |
-         sample_position_8x[4 + i].y << (8 * i);
+      render->sample_pattern_8x[0] |=
+         pack_sample_position(&ilo_sample_pattern_8x[i]) << (8 * i);
+      render->sample_pattern_8x[1] |=
+         pack_sample_position(&ilo_sample_pattern_8x[i + 4]) << (8 * i);
    }
 
    ilo_render_invalidate_hw(render);
@@ -124,20 +130,20 @@ ilo_render_get_sample_position(const struct ilo_render *render,
                                unsigned sample_index,
                                float *x, float *y)
 {
-   const struct sample_position *pos;
+   const struct sample_position *pattern;
 
    switch (sample_count) {
    case 1:
-      assert(sample_index < Elements(sample_position_1x));
-      pos = sample_position_1x;
+      assert(sample_index < Elements(ilo_sample_pattern_1x));
+      pattern = ilo_sample_pattern_1x;
       break;
    case 4:
-      assert(sample_index < Elements(sample_position_4x));
-      pos = sample_position_4x;
+      assert(sample_index < Elements(ilo_sample_pattern_4x));
+      pattern = ilo_sample_pattern_4x;
       break;
    case 8:
-      assert(sample_index < Elements(sample_position_8x));
-      pos = sample_position_8x;
+      assert(sample_index < Elements(ilo_sample_pattern_8x));
+      pattern = ilo_sample_pattern_8x;
       break;
    default:
       assert(!"unknown sample count");
@@ -147,8 +153,7 @@ ilo_render_get_sample_position(const struct ilo_render *render,
       break;
    }
 
-   *x = (float) pos[sample_index].x / 16.0f;
-   *y = (float) pos[sample_index].y / 16.0f;
+   get_sample_position(&pattern[sample_index], x, y);
 }
 
 void
diff --git a/src/gallium/drivers/ilo/ilo_render_gen.h b/src/gallium/drivers/ilo/ilo_render_gen.h
index 28d5030b9ae..fef01f43591 100644
--- a/src/gallium/drivers/ilo/ilo_render_gen.h
+++ b/src/gallium/drivers/ilo/ilo_render_gen.h
@@ -47,9 +47,9 @@ struct ilo_render {
 
    struct intel_bo *workaround_bo;
 
-   uint32_t packed_sample_position_1x;
-   uint32_t packed_sample_position_4x;
-   uint32_t packed_sample_position_8x[2];
+   uint32_t sample_pattern_1x;
+   uint32_t sample_pattern_4x;
+   uint32_t sample_pattern_8x[2];
 
    bool hw_ctx_changed;
 
diff --git a/src/gallium/drivers/ilo/ilo_render_gen6.c b/src/gallium/drivers/ilo/ilo_render_gen6.c
index e548287ccc4..20bab20dce1 100644
--- a/src/gallium/drivers/ilo/ilo_render_gen6.c
+++ b/src/gallium/drivers/ilo/ilo_render_gen6.c
@@ -717,10 +717,10 @@ gen6_draw_wm_multisample(struct ilo_render *r,
 {
    /* 3DSTATE_MULTISAMPLE and 3DSTATE_SAMPLE_MASK */
    if (DIRTY(SAMPLE_MASK) || DIRTY(FB)) {
-      const uint32_t *packed_sample_pos;
+      const uint32_t *pattern;
 
-      packed_sample_pos = (vec->fb.num_samples > 1) ?
-         &r->packed_sample_position_4x : &r->packed_sample_position_1x;
+      pattern = (vec->fb.num_samples > 1) ?
+         &r->sample_pattern_4x : &r->sample_pattern_1x;
 
       if (ilo_dev_gen(r->dev) == ILO_GEN(6)) {
          gen6_wa_pre_non_pipelined(r);
@@ -728,7 +728,7 @@ gen6_draw_wm_multisample(struct ilo_render *r,
       }
 
       gen6_3DSTATE_MULTISAMPLE(r->builder,
-            vec->fb.num_samples, packed_sample_pos,
+            vec->fb.num_samples, pattern,
             vec->rasterizer->state.half_pixel_center);
 
       gen6_3DSTATE_SAMPLE_MASK(r->builder,
@@ -920,13 +920,13 @@ static void
 gen6_rectlist_wm_multisample(struct ilo_render *r,
                              const struct ilo_blitter *blitter)
 {
-   const uint32_t *packed_sample_pos = (blitter->fb.num_samples > 1) ?
-      &r->packed_sample_position_4x : &r->packed_sample_position_1x;
+   const uint32_t *pattern = (blitter->fb.num_samples > 1) ?
+      &r->sample_pattern_4x : &r->sample_pattern_1x;
 
    gen6_wa_pre_3dstate_multisample(r);
 
    gen6_3DSTATE_MULTISAMPLE(r->builder, blitter->fb.num_samples,
-         packed_sample_pos, true);
+         pattern, true);
 
    gen6_3DSTATE_SAMPLE_MASK(r->builder,
          (1 << blitter->fb.num_samples) - 1);
diff --git a/src/gallium/drivers/ilo/ilo_render_gen7.c b/src/gallium/drivers/ilo/ilo_render_gen7.c
index 0c75afc2489..cc6d8c98041 100644
--- a/src/gallium/drivers/ilo/ilo_render_gen7.c
+++ b/src/gallium/drivers/ilo/ilo_render_gen7.c
@@ -611,17 +611,16 @@ gen7_draw_wm_multisample(struct ilo_render *r,
 {
    /* 3DSTATE_MULTISAMPLE and 3DSTATE_SAMPLE_MASK */
    if (DIRTY(SAMPLE_MASK) || DIRTY(FB)) {
-      const uint32_t *packed_sample_pos;
+      const uint32_t *pattern;
 
       gen7_wa_pre_3dstate_multisample(r);
 
-      packed_sample_pos =
-         (vec->fb.num_samples > 4) ? r->packed_sample_position_8x :
-         (vec->fb.num_samples > 1) ? &r->packed_sample_position_4x :
-         &r->packed_sample_position_1x;
+      pattern = (vec->fb.num_samples > 4) ? r->sample_pattern_8x :
+                (vec->fb.num_samples > 1) ? &r->sample_pattern_4x :
+                &r->sample_pattern_1x;
 
       gen6_3DSTATE_MULTISAMPLE(r->builder,
-            vec->fb.num_samples, packed_sample_pos,
+            vec->fb.num_samples, pattern,
             vec->rasterizer->state.half_pixel_center);
 
       gen7_3DSTATE_SAMPLE_MASK(r->builder,
@@ -807,15 +806,15 @@ static void
 gen7_rectlist_wm_multisample(struct ilo_render *r,
                              const struct ilo_blitter *blitter)
 {
-   const uint32_t *packed_sample_pos =
-      (blitter->fb.num_samples > 4) ? r->packed_sample_position_8x :
-      (blitter->fb.num_samples > 1) ? &r->packed_sample_position_4x :
-      &r->packed_sample_position_1x;
+   const uint32_t *pattern =
+      (blitter->fb.num_samples > 4) ? r->sample_pattern_8x :
+      (blitter->fb.num_samples > 1) ? &r->sample_pattern_4x :
+      &r->sample_pattern_1x;
 
    gen7_wa_pre_3dstate_multisample(r);
 
    gen6_3DSTATE_MULTISAMPLE(r->builder, blitter->fb.num_samples,
-         packed_sample_pos, true);
+         pattern, true);
 
    gen7_3DSTATE_SAMPLE_MASK(r->builder,
          (1 << blitter->fb.num_samples) - 1, blitter->fb.num_samples);