Mesa (gallium-0.2): cell: finish-up perspective-corrected interpolation
Brian Paul
brianp at kemper.freedesktop.org
Tue Oct 14 02:21:43 UTC 2008
Module: Mesa
Branch: gallium-0.2
Commit: dee18a147d3adaf2578d27837c8f18c92d796c9d
URL: http://cgit.freedesktop.org/mesa/mesa/commit/?id=dee18a147d3adaf2578d27837c8f18c92d796c9d
Author: Brian Paul <brian.paul at tungstengraphics.com>
Date: Mon Oct 13 19:41:26 2008 -0600
cell: finish-up perspective-corrected interpolation
---
src/gallium/drivers/cell/spu/spu_tri.c | 127 ++++++++++++++++++++-----------
1 files changed, 82 insertions(+), 45 deletions(-)
diff --git a/src/gallium/drivers/cell/spu/spu_tri.c b/src/gallium/drivers/cell/spu/spu_tri.c
index 022d21b..3f1fb4f 100644
--- a/src/gallium/drivers/cell/spu/spu_tri.c
+++ b/src/gallium/drivers/cell/spu/spu_tri.c
@@ -213,7 +213,7 @@ clip_emit_quad(struct setup_stage *setup)
* Eg: four colors will be computed (in AoS format).
*/
static INLINE void
-eval_coeff(uint slot, float x, float y, vector float result[4])
+eval_coeff(uint slot, float x, float y, vector float w, vector float result[4])
{
switch (spu.vertex_info.attrib[slot].interp_mode) {
case INTERP_CONSTANT:
@@ -222,23 +222,43 @@ eval_coeff(uint slot, float x, float y, vector float result[4])
result[QUAD_BOTTOM_LEFT] =
result[QUAD_BOTTOM_RIGHT] = setup.coef[slot].a0.v;
break;
-
case INTERP_LINEAR:
- /* fall-through, for now */
- default:
{
- register vector float dadx = setup.coef[slot].dadx.v;
- register vector float dady = setup.coef[slot].dady.v;
- register vector float topLeft
- = spu_add(setup.coef[slot].a0.v,
- spu_add(spu_mul(spu_splats(x), dadx),
- spu_mul(spu_splats(y), dady)));
+ vector float dadx = setup.coef[slot].dadx.v;
+ vector float dady = setup.coef[slot].dady.v;
+ vector float topLeft =
+ spu_add(setup.coef[slot].a0.v,
+ spu_add(spu_mul(spu_splats(x), dadx),
+ spu_mul(spu_splats(y), dady)));
result[QUAD_TOP_LEFT] = topLeft;
result[QUAD_TOP_RIGHT] = spu_add(topLeft, dadx);
result[QUAD_BOTTOM_LEFT] = spu_add(topLeft, dady);
result[QUAD_BOTTOM_RIGHT] = spu_add(spu_add(topLeft, dadx), dady);
}
+ break;
+ case INTERP_PERSPECTIVE:
+ {
+ vector float dadx = setup.coef[slot].dadx.v;
+ vector float dady = setup.coef[slot].dady.v;
+ vector float topLeft =
+ spu_add(setup.coef[slot].a0.v,
+ spu_add(spu_mul(spu_splats(x), dadx),
+ spu_mul(spu_splats(y), dady)));
+
+ vector float wInv = spu_re(w); /* 1.0 / w */
+
+ result[QUAD_TOP_LEFT] = spu_mul(topLeft, wInv);
+ result[QUAD_TOP_RIGHT] = spu_mul(spu_add(topLeft, dadx), wInv);
+ result[QUAD_BOTTOM_LEFT] = spu_mul(spu_add(topLeft, dady), wInv);
+ result[QUAD_BOTTOM_RIGHT] = spu_mul(spu_add(spu_add(topLeft, dadx), dady), wInv);
+ }
+ break;
+ case INTERP_POS:
+ case INTERP_NONE:
+ break;
+ default:
+ ASSERT(0);
}
}
@@ -248,14 +268,14 @@ eval_coeff(uint slot, float x, float y, vector float result[4])
* XXX this will all be re-written someday.
*/
static INLINE void
-eval_coeff_soa(uint slot, float x, float y, vector float result[4])
+eval_coeff_soa(uint slot, float x, float y, vector float w, vector float result[4])
{
- eval_coeff(slot, x, y, result);
+ eval_coeff(slot, x, y, w, result);
_transpose_matrix4x4(result, result);
}
-
+/** Evalute coefficients to get Z for four pixels in a quad */
static INLINE vector float
eval_z(float x, float y)
{
@@ -269,6 +289,20 @@ eval_z(float x, float y)
}
+/** Evalute coefficients to get W for four pixels in a quad */
+static INLINE vector float
+eval_w(float x, float y)
+{
+ const uint slot = 0;
+ const float dwdx = setup.coef[slot].dadx.f[3];
+ const float dwdy = setup.coef[slot].dady.f[3];
+ const float topLeft = setup.coef[slot].a0.f[3] + x * dwdx + y * dwdy;
+ const vector float topLeftv = spu_splats(topLeft);
+ const vector float derivs = (vector float) { 0.0, dwdx, dwdy, dwdx + dwdy };
+ return spu_add(topLeftv, derivs);
+}
+
+
/**
* Emit a quad (pass to next stage). No clipping is done.
* Note: about 1/5 to 1/7 of the time, mask is zero and this function
@@ -292,14 +326,15 @@ emit_quad( int x, int y, mask_t mask)
*/
vector float inputs[4*4], outputs[2*4];
vector float fragZ = eval_z((float) x, (float) y);
+ vector float fragW = eval_w((float) x, (float) y);
/* setup inputs */
#if 0
- eval_coeff_soa(1, (float) x, (float) y, inputs);
+ eval_coeff_soa(1, (float) x, (float) y, fragW, inputs);
#else
uint i;
for (i = 0; i < spu.vertex_info.num_attribs; i++) {
- eval_coeff_soa(i+1, (float) x, (float) y, inputs + i * 4);
+ eval_coeff_soa(i+1, (float) x, (float) y, fragW, inputs + i * 4);
}
#endif
ASSERT(spu.fragment_program);
@@ -658,7 +693,6 @@ tri_linear_coeff4(uint slot)
-#if 0
/**
* Compute a0, dadx and dady for a perspective-corrected interpolant,
* for a triangle.
@@ -667,38 +701,41 @@ tri_linear_coeff4(uint slot)
* Later, when we compute the value at a particular fragment position we'll
* divide the interpolated value by the interpolated W at that fragment.
*/
-static void tri_persp_coeff( unsigned slot,
- unsigned i )
+static void
+tri_persp_coeff4(uint slot)
{
- /* premultiply by 1/w:
- */
- float mina = setup.vmin->data[slot][i] * setup.vmin->data[0][3];
- float mida = setup.vmid->data[slot][i] * setup.vmid->data[0][3];
- float maxa = setup.vmax->data[slot][i] * setup.vmax->data[0][3];
-
- float botda = mida - mina;
- float majda = maxa - mina;
- float a = setup.ebot.dy * majda - botda * setup.emaj.dy;
- float b = setup.emaj.dx * botda - majda * setup.ebot.dx;
-
- /*
- printf("tri persp %d,%d: %f %f %f\n", slot, i,
- setup.vmin->data[slot][i],
- setup.vmid->data[slot][i],
- setup.vmax->data[slot][i]
- );
- */
+ const vector float xxxx = spu_splats(spu_extract(setup.vmin->data[0], 0) - 0.5f);
+ const vector float yyyy = spu_splats(spu_extract(setup.vmin->data[0], 1) - 0.5f);
+
+ const vector float vmin_w = spu_splats(spu_extract(setup.vmin->data[0], 3));
+ const vector float vmid_w = spu_splats(spu_extract(setup.vmid->data[0], 3));
+ const vector float vmax_w = spu_splats(spu_extract(setup.vmax->data[0], 3));
- assert(slot < PIPE_MAX_SHADER_INPUTS);
- assert(i <= 3);
+ vector float vmin_d = setup.vmin->data[slot];
+ vector float vmid_d = setup.vmid->data[slot];
+ vector float vmax_d = setup.vmax->data[slot];
- setup.coef[slot].dadx.f[i] = a * setup.oneoverarea;
- setup.coef[slot].dady.f[i] = b * setup.oneoverarea;
- setup.coef[slot].a0.f[i] = (mina -
- (setup.coef[slot].dadx.f[i] * (setup.vmin->data[0][0] - 0.5f) +
- setup.coef[slot].dady.f[i] * (setup.vmin->data[0][1] - 0.5f)));
+ vmin_d = spu_mul(vmin_d, vmin_w);
+ vmid_d = spu_mul(vmid_d, vmid_w);
+ vmax_d = spu_mul(vmax_d, vmax_w);
+
+ vector float botda = vmid_d - vmin_d;
+ vector float majda = vmax_d - vmin_d;
+
+ vector float a = spu_sub(spu_mul(spu_splats(setup.ebot.dy), majda),
+ spu_mul(botda, spu_splats(setup.emaj.dy)));
+ vector float b = spu_sub(spu_mul(spu_splats(setup.emaj.dx), botda),
+ spu_mul(majda, spu_splats(setup.ebot.dx)));
+
+ setup.coef[slot].dadx.v = spu_mul(a, spu_splats(setup.oneoverarea));
+ setup.coef[slot].dady.v = spu_mul(b, spu_splats(setup.oneoverarea));
+
+ vector float tempx = spu_mul(setup.coef[slot].dadx.v, xxxx);
+ vector float tempy = spu_mul(setup.coef[slot].dady.v, yyyy);
+
+ setup.coef[slot].a0.v = spu_sub(vmin_d, spu_add(tempx, tempy));
}
-#endif
+
/**
@@ -726,7 +763,7 @@ static void setup_tri_coefficients(void)
tri_linear_coeff4(i);
break;
case INTERP_PERSPECTIVE:
- tri_linear_coeff4(i); /* temporary */
+ tri_persp_coeff4(i);
break;
default:
ASSERT(0);
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