* Z31 Z32 Z41 Z42 Z33 Z34 Z43 Z44 ...
* ... ... ... ... ... ... ... ... ...
*
- * FIXME: Code generate stencil test
+ *
+ * Stencil test:
+ * Two-sided stencil test is supported but probably not as efficient as
+ * it could be. Currently, we use if/then/else constructs to do the
+ * operations for front vs. back-facing polygons. We could probably do
+ * both the front and back arithmetic then use a Select() instruction to
+ * choose the result depending on polyon orientation. We'd have to
+ * measure performance both ways and see which is better.
*
* @author Jose Fonseca <jfonseca@vmware.com>
*/
#include "util/u_format.h"
#include "lp_bld_type.h"
+#include "lp_bld_arit.h"
#include "lp_bld_const.h"
#include "lp_bld_logic.h"
#include "lp_bld_flow.h"
#include "lp_bld_debug.h"
#include "lp_bld_depth.h"
+#include "lp_bld_swizzle.h"
+
+
+/** Used to select fields from pipe_stencil_state */
+enum stencil_op {
+ S_FAIL_OP,
+ Z_FAIL_OP,
+ Z_PASS_OP
+};
+
+
+
+/**
+ * Do the stencil test comparison (compare FB stencil values against ref value).
+ * This will be used twice when generating two-sided stencil code.
+ * \param stencil the front/back stencil state
+ * \param stencilRef the stencil reference value, replicated as a vector
+ * \param stencilVals vector of stencil values from framebuffer
+ * \return vector mask of pass/fail values (~0 or 0)
+ */
+static LLVMValueRef
+lp_build_stencil_test_single(struct lp_build_context *bld,
+ const struct pipe_stencil_state *stencil,
+ LLVMValueRef stencilRef,
+ LLVMValueRef stencilVals)
+{
+ const unsigned stencilMax = 255; /* XXX fix */
+ struct lp_type type = bld->type;
+ LLVMValueRef res;
+
+ assert(type.sign);
+
+ assert(stencil->enabled);
+
+ if (stencil->valuemask != stencilMax) {
+ /* compute stencilRef = stencilRef & valuemask */
+ LLVMValueRef valuemask = lp_build_const_int_vec(type, stencil->valuemask);
+ stencilRef = LLVMBuildAnd(bld->builder, stencilRef, valuemask, "");
+ /* compute stencilVals = stencilVals & valuemask */
+ stencilVals = LLVMBuildAnd(bld->builder, stencilVals, valuemask, "");
+ }
+
+ res = lp_build_cmp(bld, stencil->func, stencilRef, stencilVals);
+
+ return res;
+}
+
+
+/**
+ * Do the one or two-sided stencil test comparison.
+ * \sa lp_build_stencil_test_single
+ * \param face an integer indicating front (+) or back (-) facing polygon.
+ * If NULL, assume front-facing.
+ */
+static LLVMValueRef
+lp_build_stencil_test(struct lp_build_context *bld,
+ const struct pipe_stencil_state stencil[2],
+ LLVMValueRef stencilRefs[2],
+ LLVMValueRef stencilVals,
+ LLVMValueRef face)
+{
+ LLVMValueRef res;
+
+ assert(stencil[0].enabled);
+
+ if (stencil[1].enabled && face) {
+ /* do two-sided test */
+ struct lp_build_flow_context *flow_ctx;
+ struct lp_build_if_state if_ctx;
+ LLVMValueRef front_facing;
+ LLVMValueRef zero = LLVMConstReal(LLVMFloatType(), 0.0);
+ LLVMValueRef result = bld->undef;
+
+ flow_ctx = lp_build_flow_create(bld->builder);
+ lp_build_flow_scope_begin(flow_ctx);
+
+ lp_build_flow_scope_declare(flow_ctx, &result);
+
+ /* front_facing = face > 0.0 */
+ front_facing = LLVMBuildFCmp(bld->builder, LLVMRealUGT, face, zero, "");
+
+ lp_build_if(&if_ctx, flow_ctx, bld->builder, front_facing);
+ {
+ result = lp_build_stencil_test_single(bld, &stencil[0],
+ stencilRefs[0], stencilVals);
+ }
+ lp_build_else(&if_ctx);
+ {
+ result = lp_build_stencil_test_single(bld, &stencil[1],
+ stencilRefs[1], stencilVals);
+ }
+ lp_build_endif(&if_ctx);
+
+ lp_build_flow_scope_end(flow_ctx);
+ lp_build_flow_destroy(flow_ctx);
+
+ res = result;
+ }
+ else {
+ /* do single-side test */
+ res = lp_build_stencil_test_single(bld, &stencil[0],
+ stencilRefs[0], stencilVals);
+ }
+
+ return res;
+}
+
+
+/**
+ * Apply the stencil operator (add/sub/keep/etc) to the given vector
+ * of stencil values.
+ * \return new stencil values vector
+ */
+static LLVMValueRef
+lp_build_stencil_op_single(struct lp_build_context *bld,
+ const struct pipe_stencil_state *stencil,
+ enum stencil_op op,
+ LLVMValueRef stencilRef,
+ LLVMValueRef stencilVals,
+ LLVMValueRef mask)
+
+{
+ const unsigned stencilMax = 255; /* XXX fix */
+ struct lp_type type = bld->type;
+ LLVMValueRef res;
+ LLVMValueRef max = lp_build_const_int_vec(type, stencilMax);
+ unsigned stencil_op;
+
+ assert(type.sign);
+
+ switch (op) {
+ case S_FAIL_OP:
+ stencil_op = stencil->fail_op;
+ break;
+ case Z_FAIL_OP:
+ stencil_op = stencil->zfail_op;
+ break;
+ case Z_PASS_OP:
+ stencil_op = stencil->zpass_op;
+ break;
+ default:
+ assert(0 && "Invalid stencil_op mode");
+ stencil_op = PIPE_STENCIL_OP_KEEP;
+ }
+
+ switch (stencil_op) {
+ case PIPE_STENCIL_OP_KEEP:
+ res = stencilVals;
+ /* we can return early for this case */
+ return res;
+ case PIPE_STENCIL_OP_ZERO:
+ res = bld->zero;
+ break;
+ case PIPE_STENCIL_OP_REPLACE:
+ res = stencilRef;
+ break;
+ case PIPE_STENCIL_OP_INCR:
+ res = lp_build_add(bld, stencilVals, bld->one);
+ res = lp_build_min(bld, res, max);
+ break;
+ case PIPE_STENCIL_OP_DECR:
+ res = lp_build_sub(bld, stencilVals, bld->one);
+ res = lp_build_max(bld, res, bld->zero);
+ break;
+ case PIPE_STENCIL_OP_INCR_WRAP:
+ res = lp_build_add(bld, stencilVals, bld->one);
+ res = LLVMBuildAnd(bld->builder, res, max, "");
+ break;
+ case PIPE_STENCIL_OP_DECR_WRAP:
+ res = lp_build_sub(bld, stencilVals, bld->one);
+ res = LLVMBuildAnd(bld->builder, res, max, "");
+ break;
+ case PIPE_STENCIL_OP_INVERT:
+ res = LLVMBuildNot(bld->builder, stencilVals, "");
+ res = LLVMBuildAnd(bld->builder, res, max, "");
+ break;
+ default:
+ assert(0 && "bad stencil op mode");
+ res = NULL;
+ }
+
+ if (stencil->writemask != stencilMax) {
+ /* compute res = (res & mask) | (stencilVals & ~mask) */
+ LLVMValueRef mask = lp_build_const_int_vec(type, stencil->writemask);
+ LLVMValueRef cmask = LLVMBuildNot(bld->builder, mask, "notWritemask");
+ LLVMValueRef t1 = LLVMBuildAnd(bld->builder, res, mask, "t1");
+ LLVMValueRef t2 = LLVMBuildAnd(bld->builder, stencilVals, cmask, "t2");
+ res = LLVMBuildOr(bld->builder, t1, t2, "t1_or_t2");
+ }
+
+ /* only the update the vector elements enabled by 'mask' */
+ res = lp_build_select(bld, mask, res, stencilVals);
+
+ return res;
+}
+
+
+/**
+ * Do the one or two-sided stencil test op/update.
+ */
+static LLVMValueRef
+lp_build_stencil_op(struct lp_build_context *bld,
+ const struct pipe_stencil_state stencil[2],
+ enum stencil_op op,
+ LLVMValueRef stencilRefs[2],
+ LLVMValueRef stencilVals,
+ LLVMValueRef mask,
+ LLVMValueRef face)
+
+{
+ assert(stencil[0].enabled);
+
+ if (stencil[1].enabled && face) {
+ /* do two-sided op */
+ struct lp_build_flow_context *flow_ctx;
+ struct lp_build_if_state if_ctx;
+ LLVMValueRef front_facing;
+ LLVMValueRef zero = LLVMConstReal(LLVMFloatType(), 0.0);
+ LLVMValueRef result = bld->undef;
+
+ flow_ctx = lp_build_flow_create(bld->builder);
+ lp_build_flow_scope_begin(flow_ctx);
+
+ lp_build_flow_scope_declare(flow_ctx, &result);
+
+ /* front_facing = face > 0.0 */
+ front_facing = LLVMBuildFCmp(bld->builder, LLVMRealUGT, face, zero, "");
+
+ lp_build_if(&if_ctx, flow_ctx, bld->builder, front_facing);
+ {
+ result = lp_build_stencil_op_single(bld, &stencil[0], op,
+ stencilRefs[0], stencilVals, mask);
+ }
+ lp_build_else(&if_ctx);
+ {
+ result = lp_build_stencil_op_single(bld, &stencil[1], op,
+ stencilRefs[1], stencilVals, mask);
+ }
+ lp_build_endif(&if_ctx);
+
+ lp_build_flow_scope_end(flow_ctx);
+ lp_build_flow_destroy(flow_ctx);
+
+ return result;
+ }
+ else {
+ /* do single-sided op */
+ return lp_build_stencil_op_single(bld, &stencil[0], op,
+ stencilRefs[0], stencilVals, mask);
+ }
+}
+
/**
/**
- * Depth test.
+ * Compute bitmask and bit shift to apply to the incoming fragment Z values
+ * and the Z buffer values needed before doing the Z comparison.
+ *
+ * Note that we leave the Z bits in the position that we find them
+ * in the Z buffer (typically 0xffffff00 or 0x00ffffff). That lets us
+ * get by with fewer bit twiddling steps.
*/
-void
-lp_build_depth_test(LLVMBuilderRef builder,
- const struct pipe_depth_state *state,
- struct lp_type type,
- const struct util_format_description *format_desc,
- struct lp_build_mask_context *mask,
- LLVMValueRef src,
- LLVMValueRef dst_ptr)
+static boolean
+get_z_shift_and_mask(const struct util_format_description *format_desc,
+ unsigned *shift, unsigned *mask)
{
- struct lp_build_context bld;
+ const unsigned total_bits = format_desc->block.bits;
unsigned z_swizzle;
- LLVMValueRef dst;
- LLVMValueRef z_bitmask = NULL;
- LLVMValueRef test;
-
- if(!state->enabled)
- return;
-
+ int chan;
+ unsigned padding_left, padding_right;
+
assert(format_desc->colorspace == UTIL_FORMAT_COLORSPACE_ZS);
assert(format_desc->block.width == 1);
assert(format_desc->block.height == 1);
z_swizzle = format_desc->swizzle[0];
- if(z_swizzle == UTIL_FORMAT_SWIZZLE_NONE)
- return;
- /* Sanity checking */
- assert(z_swizzle < 4);
- assert(format_desc->block.bits == type.width);
- if(type.floating) {
- assert(z_swizzle == 0);
- assert(format_desc->channel[z_swizzle].type == UTIL_FORMAT_TYPE_FLOAT);
- assert(format_desc->channel[z_swizzle].size == format_desc->block.bits);
+ if (z_swizzle == UTIL_FORMAT_SWIZZLE_NONE)
+ return FALSE;
+
+ padding_right = 0;
+ for (chan = 0; chan < z_swizzle; ++chan)
+ padding_right += format_desc->channel[chan].size;
+
+ padding_left =
+ total_bits - (padding_right + format_desc->channel[z_swizzle].size);
+
+ if (padding_left || padding_right) {
+ unsigned long long mask_left = (1ULL << (total_bits - padding_left)) - 1;
+ unsigned long long mask_right = (1ULL << (padding_right)) - 1;
+ *mask = mask_left ^ mask_right;
}
else {
- assert(format_desc->channel[z_swizzle].type == UTIL_FORMAT_TYPE_UNSIGNED);
- assert(format_desc->channel[z_swizzle].normalized);
- assert(!type.fixed);
- assert(!type.sign);
- assert(type.norm);
+ *mask = 0xffffffff;
+ }
+
+ *shift = padding_left;
+
+ return TRUE;
+}
+
+
+/**
+ * Compute bitmask and bit shift to apply to the framebuffer pixel values
+ * to put the stencil bits in the least significant position.
+ * (i.e. 0x000000ff)
+ */
+static boolean
+get_s_shift_and_mask(const struct util_format_description *format_desc,
+ unsigned *shift, unsigned *mask)
+{
+ unsigned s_swizzle;
+ int chan, sz;
+
+ s_swizzle = format_desc->swizzle[1];
+
+ if (s_swizzle == UTIL_FORMAT_SWIZZLE_NONE)
+ return FALSE;
+
+ *shift = 0;
+ for (chan = 0; chan < s_swizzle; chan++)
+ *shift += format_desc->channel[chan].size;
+
+ sz = format_desc->channel[s_swizzle].size;
+ *mask = (1U << sz) - 1U;
+
+ return TRUE;
+}
+
+
+
+/**
+ * Generate code for performing depth and/or stencil tests.
+ * We operate on a vector of values (typically a 2x2 quad).
+ *
+ * \param depth the depth test state
+ * \param stencil the front/back stencil state
+ * \param type the data type of the fragment depth/stencil values
+ * \param format_desc description of the depth/stencil surface
+ * \param mask the alive/dead pixel mask for the quad (vector)
+ * \param stencil_refs the front/back stencil ref values (scalar)
+ * \param z_src the incoming depth/stencil values (a 2x2 quad)
+ * \param zs_dst_ptr pointer to depth/stencil values in framebuffer
+ * \param facing contains float value indicating front/back facing polygon
+ */
+void
+lp_build_depth_stencil_test(LLVMBuilderRef builder,
+ const struct pipe_depth_state *depth,
+ const struct pipe_stencil_state stencil[2],
+ struct lp_type type,
+ const struct util_format_description *format_desc,
+ struct lp_build_mask_context *mask,
+ LLVMValueRef stencil_refs[2],
+ LLVMValueRef z_src,
+ LLVMValueRef zs_dst_ptr,
+ LLVMValueRef face)
+{
+ struct lp_build_context bld;
+ struct lp_build_context sbld;
+ struct lp_type s_type;
+ LLVMValueRef zs_dst, z_dst = NULL;
+ LLVMValueRef stencil_vals = NULL;
+ LLVMValueRef z_bitmask = NULL, stencil_shift = NULL;
+ LLVMValueRef z_pass = NULL, s_pass_mask = NULL;
+ LLVMValueRef orig_mask = mask->value;
+
+ /* Sanity checking */
+ {
+ const unsigned z_swizzle = format_desc->swizzle[0];
+ const unsigned s_swizzle = format_desc->swizzle[1];
+
+ assert(z_swizzle != UTIL_FORMAT_SWIZZLE_NONE ||
+ s_swizzle != UTIL_FORMAT_SWIZZLE_NONE);
+
+ assert(depth->enabled || stencil[0].enabled);
+
+ assert(format_desc->colorspace == UTIL_FORMAT_COLORSPACE_ZS);
+ assert(format_desc->block.width == 1);
+ assert(format_desc->block.height == 1);
+
+ if (stencil[0].enabled) {
+ assert(format_desc->format == PIPE_FORMAT_Z24_UNORM_S8_USCALED ||
+ format_desc->format == PIPE_FORMAT_S8_USCALED_Z24_UNORM);
+ }
+
+ assert(z_swizzle < 4);
+ assert(format_desc->block.bits == type.width);
+ if (type.floating) {
+ assert(z_swizzle == 0);
+ assert(format_desc->channel[z_swizzle].type ==
+ UTIL_FORMAT_TYPE_FLOAT);
+ assert(format_desc->channel[z_swizzle].size ==
+ format_desc->block.bits);
+ }
+ else {
+ assert(format_desc->channel[z_swizzle].type ==
+ UTIL_FORMAT_TYPE_UNSIGNED);
+ assert(format_desc->channel[z_swizzle].normalized);
+ assert(!type.fixed);
+ assert(!type.sign);
+ assert(type.norm);
+ }
}
- /* Setup build context */
+
+ /* Setup build context for Z vals */
lp_build_context_init(&bld, builder, type);
- dst = LLVMBuildLoad(builder, dst_ptr, "");
+ /* Setup build context for stencil vals */
+ s_type = lp_type_int_vec(type.width);
+ lp_build_context_init(&sbld, builder, s_type);
+
+ /* Load current z/stencil value from z/stencil buffer */
+ zs_dst = LLVMBuildLoad(builder, zs_dst_ptr, "");
+
+ lp_build_name(zs_dst, "zsbufval");
- lp_build_name(dst, "zsbuf");
- /* Align the source depth bits with the destination's, and mask out any
- * stencil or padding bits from both */
- if(format_desc->channel[z_swizzle].size == format_desc->block.bits) {
- assert(z_swizzle == 0);
- /* nothing to do */
+ /* Compute and apply the Z/stencil bitmasks and shifts.
+ */
+ {
+ unsigned z_shift, z_mask;
+ unsigned s_shift, s_mask;
+
+ if (get_z_shift_and_mask(format_desc, &z_shift, &z_mask)) {
+ if (z_shift) {
+ LLVMValueRef shift = lp_build_const_int_vec(type, z_shift);
+ z_src = LLVMBuildLShr(builder, z_src, shift, "");
+ }
+
+ if (z_mask != 0xffffffff) {
+ LLVMValueRef mask = lp_build_const_int_vec(type, z_mask);
+ z_src = LLVMBuildAnd(builder, z_src, mask, "");
+ z_dst = LLVMBuildAnd(builder, zs_dst, mask, "");
+ z_bitmask = mask; /* used below */
+ }
+ else {
+ z_dst = zs_dst;
+ }
+
+ lp_build_name(z_dst, "zsbuf.z");
+ }
+
+ if (get_s_shift_and_mask(format_desc, &s_shift, &s_mask)) {
+ if (s_shift) {
+ LLVMValueRef shift = lp_build_const_int_vec(type, s_shift);
+ stencil_vals = LLVMBuildLShr(builder, zs_dst, shift, "");
+ stencil_shift = shift; /* used below */
+ }
+ else {
+ stencil_vals = zs_dst;
+ }
+
+ if (s_mask != 0xffffffff) {
+ LLVMValueRef mask = lp_build_const_int_vec(type, s_mask);
+ stencil_vals = LLVMBuildAnd(builder, stencil_vals, mask, "");
+ }
+
+ lp_build_name(stencil_vals, "stencil");
+ }
}
- else {
- unsigned padding_left;
- unsigned padding_right;
- unsigned chan;
-
- assert(format_desc->layout == UTIL_FORMAT_LAYOUT_PLAIN);
- assert(format_desc->channel[z_swizzle].type == UTIL_FORMAT_TYPE_UNSIGNED);
- assert(format_desc->channel[z_swizzle].size <= format_desc->block.bits);
- assert(format_desc->channel[z_swizzle].normalized);
-
- padding_right = 0;
- for(chan = 0; chan < z_swizzle; ++chan)
- padding_right += format_desc->channel[chan].size;
- padding_left = format_desc->block.bits -
- (padding_right + format_desc->channel[z_swizzle].size);
-
- if(padding_left || padding_right) {
- const unsigned long long mask_left = ((unsigned long long)1 << (format_desc->block.bits - padding_left)) - 1;
- const unsigned long long mask_right = ((unsigned long long)1 << (padding_right)) - 1;
- z_bitmask = lp_build_int_const_scalar(type, mask_left ^ mask_right);
+
+
+ if (stencil[0].enabled) {
+ /* convert scalar stencil refs into vectors */
+ stencil_refs[0] = lp_build_broadcast_scalar(&bld, stencil_refs[0]);
+ stencil_refs[1] = lp_build_broadcast_scalar(&bld, stencil_refs[1]);
+
+ s_pass_mask = lp_build_stencil_test(&sbld, stencil,
+ stencil_refs, stencil_vals, face);
+
+ /* apply stencil-fail operator */
+ {
+ LLVMValueRef s_fail_mask = lp_build_andc(&bld, orig_mask, s_pass_mask);
+ stencil_vals = lp_build_stencil_op(&sbld, stencil, S_FAIL_OP,
+ stencil_refs, stencil_vals,
+ s_fail_mask, face);
+ }
+ }
+
+ if (depth->enabled) {
+ /* compare src Z to dst Z, returning 'pass' mask */
+ z_pass = lp_build_cmp(&bld, depth->func, z_src, z_dst);
+
+ if (!stencil[0].enabled) {
+ /* We can potentially skip all remaining operations here, but only
+ * if stencil is disabled because we still need to update the stencil
+ * buffer values. Don't need to update Z buffer values.
+ */
+ lp_build_mask_update(mask, z_pass);
+ }
+
+ if (depth->writemask) {
+ if(z_bitmask)
+ z_bitmask = LLVMBuildAnd(builder, mask->value, z_bitmask, "");
+ else
+ z_bitmask = mask->value;
+
+ z_dst = lp_build_select(&bld, z_bitmask, z_src, z_dst);
}
- if(padding_left)
- src = LLVMBuildLShr(builder, src, lp_build_int_const_scalar(type, padding_left), "");
- if(padding_right)
- src = LLVMBuildAnd(builder, src, z_bitmask, "");
- if(padding_left || padding_right)
- dst = LLVMBuildAnd(builder, dst, z_bitmask, "");
+ if (stencil[0].enabled) {
+ /* update stencil buffer values according to z pass/fail result */
+ LLVMValueRef z_fail_mask, z_pass_mask;
+
+ /* apply Z-fail operator */
+ z_fail_mask = lp_build_andc(&bld, orig_mask, z_pass);
+ stencil_vals = lp_build_stencil_op(&sbld, stencil, Z_FAIL_OP,
+ stencil_refs, stencil_vals,
+ z_fail_mask, face);
+
+ /* apply Z-pass operator */
+ z_pass_mask = LLVMBuildAnd(bld.builder, orig_mask, z_pass, "");
+ stencil_vals = lp_build_stencil_op(&sbld, stencil, Z_PASS_OP,
+ stencil_refs, stencil_vals,
+ z_pass_mask, face);
+ }
+ }
+ else {
+ /* No depth test: apply Z-pass operator to stencil buffer values which
+ * passed the stencil test.
+ */
+ s_pass_mask = LLVMBuildAnd(bld.builder, orig_mask, s_pass_mask, "");
+ stencil_vals = lp_build_stencil_op(&sbld, stencil, Z_PASS_OP,
+ stencil_refs, stencil_vals,
+ s_pass_mask, face);
}
- lp_build_name(dst, "zsbuf.z");
+ /* The Z bits are already in the right place but we may need to shift the
+ * stencil bits before ORing Z with Stencil to make the final pixel value.
+ */
+ if (stencil_vals && stencil_shift)
+ stencil_vals = LLVMBuildShl(bld.builder, stencil_vals,
+ stencil_shift, "");
- test = lp_build_cmp(&bld, state->func, src, dst);
- lp_build_mask_update(mask, test);
+ /* Finally, merge/store the z/stencil values */
+ if ((depth->enabled && depth->writemask) ||
+ (stencil[0].enabled && stencil[0].writemask)) {
- if(state->writemask) {
- if(z_bitmask)
- z_bitmask = LLVMBuildAnd(builder, mask->value, z_bitmask, "");
+ if (z_dst && stencil_vals)
+ zs_dst = LLVMBuildOr(bld.builder, z_dst, stencil_vals, "");
+ else if (z_dst)
+ zs_dst = z_dst;
else
- z_bitmask = mask->value;
+ zs_dst = stencil_vals;
- dst = lp_build_select(&bld, z_bitmask, src, dst);
- LLVMBuildStore(builder, dst, dst_ptr);
+ LLVMBuildStore(builder, zs_dst, zs_dst_ptr);
}
+
+ if (s_pass_mask)
+ lp_build_mask_update(mask, s_pass_mask);
+
+ if (depth->enabled && stencil[0].enabled)
+ lp_build_mask_update(mask, z_pass);
}
projects / mesa.git / blobdiff