[Mesa-dev] [PATCH 7/8] i965/fs: Add support for TXD with shadow comparisons.
Kenneth Graunke
kenneth at whitecape.org
Fri Jun 17 20:01:27 PDT 2011
Our hardware doesn't have a sample_d_c message, so we have to do a
regular sample_d and emit instructions to manually perform the
comparison.
This requires a state dependent recompile whenever the sampler's compare
mode or function change. This adds the per-sampler comparison functions
to brw_wm_prog_key, but only sets them when the sampler's compare mode
is GL_COMPARE_R_TO_TEXTURE (i.e. only for shadow sampling).
Signed-off-by: Kenneth Graunke <kenneth at whitecape.org>
---
src/mesa/drivers/dri/i965/brw_fs.cpp | 3 +
src/mesa/drivers/dri/i965/brw_fs_emit.cpp | 4 +-
src/mesa/drivers/dri/i965/brw_fs_visitor.cpp | 62 +++++++++++++++++++++++--
src/mesa/drivers/dri/i965/brw_wm.c | 2 +
src/mesa/drivers/dri/i965/brw_wm.h | 12 +++++
5 files changed, 76 insertions(+), 7 deletions(-)
diff --git a/src/mesa/drivers/dri/i965/brw_fs.cpp b/src/mesa/drivers/dri/i965/brw_fs.cpp
index 3a16afe..fd0740a 100644
--- a/src/mesa/drivers/dri/i965/brw_fs.cpp
+++ b/src/mesa/drivers/dri/i965/brw_fs.cpp
@@ -1686,6 +1686,9 @@ brw_fs_precompile(struct gl_context *ctx, struct gl_shader_program *prog)
key.clamp_fragment_color = true;
for (int i = 0; i < BRW_MAX_TEX_UNIT; i++) {
+ if (fp->Base.ShadowSamplers & (1 << i))
+ key.compare_funcs[i] = GL_LESS;
+
/* FINISHME: depth compares might use (0,0,0,W) for example */
key.tex_swizzles[i] = SWIZZLE_XYZW;
}
diff --git a/src/mesa/drivers/dri/i965/brw_fs_emit.cpp b/src/mesa/drivers/dri/i965/brw_fs_emit.cpp
index 1c522cb..1d89b8f 100644
--- a/src/mesa/drivers/dri/i965/brw_fs_emit.cpp
+++ b/src/mesa/drivers/dri/i965/brw_fs_emit.cpp
@@ -273,7 +273,7 @@ fs_visitor::generate_tex(fs_inst *inst, struct brw_reg dst, struct brw_reg src)
}
break;
case FS_OPCODE_TXD:
- assert(!inst->shadow_compare);
+ /* There is no sample_d_c message; comparisons are done manually */
msg_type = GEN5_SAMPLER_MESSAGE_SAMPLE_DERIVS;
break;
}
@@ -312,7 +312,7 @@ fs_visitor::generate_tex(fs_inst *inst, struct brw_reg dst, struct brw_reg src)
}
break;
case FS_OPCODE_TXD:
- assert(!inst->shadow_compare); // not supported yet
+ /* There is no sample_d_c message; comparisons are done manually */
assert(inst->mlen == 7 || inst->mlen == 10);
msg_type = BRW_SAMPLER_MESSAGE_SIMD8_SAMPLE_GRADIENTS;
break;
diff --git a/src/mesa/drivers/dri/i965/brw_fs_visitor.cpp b/src/mesa/drivers/dri/i965/brw_fs_visitor.cpp
index 35bda58..6116b10 100644
--- a/src/mesa/drivers/dri/i965/brw_fs_visitor.cpp
+++ b/src/mesa/drivers/dri/i965/brw_fs_visitor.cpp
@@ -549,7 +549,7 @@ fs_visitor::emit_texture_gen4(ir_texture *ir, fs_reg dst, fs_reg coordinate,
/* g0 header. */
mlen = 1;
- if (ir->shadow_comparitor) {
+ if (ir->shadow_comparitor && ir->op != ir_txd) {
for (int i = 0; i < ir->coordinate->type->vector_elements; i++) {
fs_inst *inst = emit(BRW_OPCODE_MOV,
fs_reg(MRF, base_mrf + mlen + i), coordinate);
@@ -744,7 +744,7 @@ fs_visitor::emit_texture_gen5(ir_texture *ir, fs_reg dst, fs_reg coordinate,
}
mlen += ir->coordinate->type->vector_elements * reg_width;
- if (ir->shadow_comparitor) {
+ if (ir->shadow_comparitor && ir->op != ir_txd) {
mlen = MAX2(mlen, header_present + 4 * reg_width);
this->result = reg_undef;
@@ -841,7 +841,7 @@ fs_visitor::emit_texture_gen7(ir_texture *ir, fs_reg dst, fs_reg coordinate,
base_mrf--;
}
- if (ir->shadow_comparitor) {
+ if (ir->shadow_comparitor && ir->op != ir_txd) {
ir->shadow_comparitor->accept(this);
emit(BRW_OPCODE_MOV, fs_reg(MRF, base_mrf + mlen), this->result);
mlen += reg_width;
@@ -937,6 +937,19 @@ fs_visitor::visit(ir_texture *ir)
int sampler = _mesa_get_sampler_uniform_value(ir->sampler, prog, &fp->Base);
sampler = fp->Base.SamplerUnits[sampler];
+ /* Our hardware doesn't have a sample_d_c message, so shadow compares
+ * for textureGrad/TXD need to be emulated with instructions.
+ */
+ bool hw_compare_supported = ir->op != ir_txd;
+ if (ir->shadow_comparitor && !hw_compare_supported) {
+ assert(c->key.compare_funcs[sampler] != GL_NONE);
+ /* No need to even sample for GL_ALWAYS or GL_NEVER...bail early */
+ if (c->key.compare_funcs[sampler] == GL_ALWAYS)
+ return swizzle_result(ir, fs_reg(1.0f), sampler);
+ else if (c->key.compare_funcs[sampler] == GL_NEVER)
+ return swizzle_result(ir, fs_reg(0.0f), sampler);
+ }
+
this->result = reg_undef;
ir->coordinate->accept(this);
fs_reg coordinate = this->result;
@@ -1045,8 +1058,47 @@ fs_visitor::visit(ir_texture *ir)
inst->sampler = sampler;
- if (ir->shadow_comparitor)
- inst->shadow_compare = true;
+ if (ir->shadow_comparitor) {
+ if (hw_compare_supported) {
+ inst->shadow_compare = true;
+ } else {
+ ir->shadow_comparitor->accept(this);
+ fs_reg ref = this->result;
+
+ fs_reg value = dst;
+ dst = fs_reg(this, glsl_type::vec4_type);
+
+ /* FINISHME: This needs to be done pre-filtering. */
+
+ uint32_t conditional = 0;
+ switch (c->key.compare_funcs[sampler]) {
+ /* GL_ALWAYS and GL_NEVER were handled at the top of the function */
+ case GL_LESS: conditional = BRW_CONDITIONAL_L; break;
+ case GL_GREATER: conditional = BRW_CONDITIONAL_G; break;
+ case GL_LEQUAL: conditional = BRW_CONDITIONAL_LE; break;
+ case GL_GEQUAL: conditional = BRW_CONDITIONAL_GE; break;
+ case GL_EQUAL: conditional = BRW_CONDITIONAL_EQ; break;
+ case GL_NOTEQUAL: conditional = BRW_CONDITIONAL_NEQ; break;
+ default: assert(!"Should not get here: bad shadow compare function");
+ }
+
+ /* Use conditional moves to load 0 or 1 as the result */
+ this->current_annotation = "manual shadow comparison";
+ for (int i = 0; i < 4; i++) {
+ inst = emit(BRW_OPCODE_MOV, dst, fs_reg(0.0f));
+
+ inst = emit(BRW_OPCODE_CMP, reg_null_f, ref, value);
+ inst->conditional_mod = conditional;
+
+ inst = emit(BRW_OPCODE_MOV, dst, fs_reg(1.0f));
+ inst->predicated = true;
+
+ dst.reg_offset++;
+ value.reg_offset++;
+ }
+ dst.reg_offset = 0;
+ }
+ }
swizzle_result(ir, dst, sampler);
}
diff --git a/src/mesa/drivers/dri/i965/brw_wm.c b/src/mesa/drivers/dri/i965/brw_wm.c
index 1aebd12..4d35ce1 100644
--- a/src/mesa/drivers/dri/i965/brw_wm.c
+++ b/src/mesa/drivers/dri/i965/brw_wm.c
@@ -389,6 +389,8 @@ static void brw_wm_populate_key( struct brw_context *brw,
* all 4 channels.
*/
if (sampler->CompareMode == GL_COMPARE_R_TO_TEXTURE_ARB) {
+ key->compare_funcs[i] = sampler->CompareFunc;
+
if (sampler->DepthMode == GL_ALPHA) {
swizzles[0] = SWIZZLE_ZERO;
swizzles[1] = SWIZZLE_ZERO;
diff --git a/src/mesa/drivers/dri/i965/brw_wm.h b/src/mesa/drivers/dri/i965/brw_wm.h
index e244b55..29082c1 100644
--- a/src/mesa/drivers/dri/i965/brw_wm.h
+++ b/src/mesa/drivers/dri/i965/brw_wm.h
@@ -68,6 +68,18 @@ struct brw_wm_prog_key {
GLuint clamp_fragment_color:1;
GLuint line_aa:2;
+ /**
+ * Per-sampler comparison functions:
+ *
+ * If comparison mode is GL_COMPARE_R_TO_TEXTURE, then this is set to one
+ * of GL_NEVER, GL_LESS, GL_EQUAL, GL_LEQUAL, GL_GREATER, GL_NOTEQUAL,
+ * GL_GEQUAL, or GL_ALWAYS. Otherwise (comparison mode is GL_NONE), this
+ * field is irrelevant so it's left as GL_NONE (0).
+ *
+ * While this is a GLenum, all possible values fit in 16-bits.
+ */
+ uint16_t compare_funcs[BRW_MAX_TEX_UNIT];
+
GLbitfield proj_attrib_mask; /**< one bit per fragment program attribute */
GLuint yuvtex_mask:16;
GLuint yuvtex_swap_mask:16; /* UV swaped */
--
1.7.5.4
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