#include "brw_defines.h"
#include "brw_util.h"
#include "intel_batchbuffer.h"
+#include "main/fbobject.h"
+#include "main/framebuffer.h"
static void
upload_clip_state(struct brw_context *brw)
{
- struct intel_context *intel = &brw->intel;
- struct gl_context *ctx = &intel->ctx;
- uint32_t depth_clamp = 0;
- uint32_t provoking, userclip;
+ struct gl_context *ctx = &brw->ctx;
+ /* BRW_NEW_META_IN_PROGRESS */
+ uint32_t dw1 = brw->meta_in_progress ? 0 : GEN6_CLIP_STATISTICS_ENABLE;
+ uint32_t dw2 = 0;
- if (!ctx->Transform.DepthClamp)
- depth_clamp = GEN6_CLIP_Z_TEST;
+ /* _NEW_BUFFERS */
+ struct gl_framebuffer *fb = ctx->DrawBuffer;
+ /* BRW_NEW_FS_PROG_DATA */
+ if (brw->wm.prog_data->barycentric_interp_modes &
+ BRW_WM_NONPERSPECTIVE_BARYCENTRIC_BITS) {
+ dw2 |= GEN6_CLIP_NON_PERSPECTIVE_BARYCENTRIC_ENABLE;
+ }
+
+ if (brw->gen >= 7)
+ dw1 |= GEN7_CLIP_EARLY_CULL;
+
+ if (brw->gen == 7) {
+ /* _NEW_POLYGON */
+ if (ctx->Polygon._FrontBit == _mesa_is_user_fbo(fb))
+ dw1 |= GEN7_CLIP_WINDING_CCW;
+
+ if (ctx->Polygon.CullFlag) {
+ switch (ctx->Polygon.CullFaceMode) {
+ case GL_FRONT:
+ dw1 |= GEN7_CLIP_CULLMODE_FRONT;
+ break;
+ case GL_BACK:
+ dw1 |= GEN7_CLIP_CULLMODE_BACK;
+ break;
+ case GL_FRONT_AND_BACK:
+ dw1 |= GEN7_CLIP_CULLMODE_BOTH;
+ break;
+ default:
+ unreachable("Should not get here: invalid CullFlag");
+ }
+ } else {
+ dw1 |= GEN7_CLIP_CULLMODE_NONE;
+ }
+ }
+
+ if (brw->gen < 8 && !ctx->Transform.DepthClamp)
+ dw2 |= GEN6_CLIP_Z_TEST;
+
+ /* _NEW_LIGHT */
if (ctx->Light.ProvokingVertex == GL_FIRST_VERTEX_CONVENTION) {
- provoking =
+ dw2 |=
(0 << GEN6_CLIP_TRI_PROVOKE_SHIFT) |
(1 << GEN6_CLIP_TRIFAN_PROVOKE_SHIFT) |
(0 << GEN6_CLIP_LINE_PROVOKE_SHIFT);
} else {
- provoking =
+ dw2 |=
(2 << GEN6_CLIP_TRI_PROVOKE_SHIFT) |
(2 << GEN6_CLIP_TRIFAN_PROVOKE_SHIFT) |
(1 << GEN6_CLIP_LINE_PROVOKE_SHIFT);
}
/* _NEW_TRANSFORM */
- userclip = (1 << brw_count_bits(ctx->Transform.ClipPlanesEnabled)) - 1;
+ dw2 |= (ctx->Transform.ClipPlanesEnabled <<
+ GEN6_USER_CLIP_CLIP_DISTANCES_SHIFT);
+ if (ctx->Transform.ClipDepthMode == GL_ZERO_TO_ONE)
+ dw2 |= GEN6_CLIP_API_D3D;
+ else
+ dw2 |= GEN6_CLIP_API_OGL;
+
+ dw2 |= GEN6_CLIP_GB_TEST;
+
+ /* We need to disable guardband clipping if the guardband (which we always
+ * program to the maximum screen-space bounding box of 8K x 8K) will be
+ * smaller than the viewport.
+ *
+ * Closely examining the clip determination formulas in the documentation
+ * reveals that objects will be discarded entirely if they're outside the
+ * (small) guardband, even if they're within the (large) viewport:
+ *
+ * TR = TR_GB || TR_VPXY || TR_VPZ || TR_UC || TR_NEGW
+ * TA = !TR && TA_GB && TA_VPZ && TA_NEGW
+ * MC = !(TA || TR)
+ *
+ * (TA is "Trivial Accept", TR is "Trivial Reject", MC is "Must Clip".)
+ *
+ * Disabling guardband clipping removes the TR_GB condition, which means
+ * they'll be considered MC ("Must Clip") unless they're rejected for
+ * some other reason.
+ *
+ * Note that there is no TA_VPXY condition. If there were, objects entirely
+ * inside a 16384x16384 viewport would be trivially accepted, breaking the
+ * "objects must have a screenspace bounding box not exceeding 8K in the X
+ * or Y direction" restriction. Instead, they're clipped.
+ */
+ for (unsigned i = 0; i < ctx->Const.MaxViewports; i++) {
+ if (ctx->ViewportArray[i].Width > 8192 ||
+ ctx->ViewportArray[i].Height > 8192) {
+ dw2 &= ~GEN6_CLIP_GB_TEST;
+ break;
+ }
+ }
+
+ /* If the viewport dimensions are smaller than the drawable dimensions,
+ * we have to disable guardband clipping prior to Gen8. We always program
+ * the guardband to a fixed size, which is almost always larger than the
+ * viewport. Any geometry which intersects the viewport but lies within
+ * the guardband would bypass the 3D clipping stage, so it wouldn't be
+ * clipped to the viewport. Rendering would happen beyond the viewport,
+ * but still inside the drawable.
+ *
+ * Gen8+ introduces a viewport extents test which restricts rendering to
+ * the viewport, so we can ignore this restriction.
+ */
+ if (brw->gen < 8) {
+ const float fb_width = (float)_mesa_geometric_width(fb);
+ const float fb_height = (float)_mesa_geometric_height(fb);
+
+ for (unsigned i = 0; i < ctx->Const.MaxViewports; i++) {
+ if (ctx->ViewportArray[i].X != 0 ||
+ ctx->ViewportArray[i].Y != 0 ||
+ ctx->ViewportArray[i].Width != fb_width ||
+ ctx->ViewportArray[i].Height != fb_height) {
+ dw2 &= ~GEN6_CLIP_GB_TEST;
+ break;
+ }
+ }
+ }
+
+ /* BRW_NEW_RASTERIZER_DISCARD */
+ if (ctx->RasterDiscard) {
+ dw2 |= GEN6_CLIP_MODE_REJECT_ALL;
+ perf_debug("Rasterizer discard is currently implemented via the clipper; "
+ "%s be faster.\n", brw->gen >= 7 ? "using the SOL unit may" :
+ "having the GS not write primitives would likely");
+ }
+
+ uint32_t enable;
+ if (brw->primitive == _3DPRIM_RECTLIST)
+ enable = 0;
+ else
+ enable = GEN6_CLIP_ENABLE;
BEGIN_BATCH(4);
OUT_BATCH(_3DSTATE_CLIP << 16 | (4 - 2));
- OUT_BATCH(GEN6_CLIP_STATISTICS_ENABLE);
- OUT_BATCH(GEN6_CLIP_ENABLE |
- GEN6_CLIP_API_OGL |
+ OUT_BATCH(dw1);
+ OUT_BATCH(enable |
GEN6_CLIP_MODE_NORMAL |
GEN6_CLIP_XY_TEST |
- userclip << GEN6_USER_CLIP_CLIP_DISTANCES_SHIFT |
- depth_clamp |
- provoking);
+ dw2);
OUT_BATCH(U_FIXED(0.125, 3) << GEN6_CLIP_MIN_POINT_WIDTH_SHIFT |
- U_FIXED(225.875, 3) << GEN6_CLIP_MAX_POINT_WIDTH_SHIFT |
- GEN6_CLIP_FORCE_ZERO_RTAINDEX);
+ U_FIXED(255.875, 3) << GEN6_CLIP_MAX_POINT_WIDTH_SHIFT |
+ (_mesa_geometric_layers(fb) > 0 ? 0 : GEN6_CLIP_FORCE_ZERO_RTAINDEX) |
+ ((ctx->Const.MaxViewports - 1) & GEN6_CLIP_MAX_VP_INDEX_MASK));
ADVANCE_BATCH();
}
const struct brw_tracked_state gen6_clip_state = {
.dirty = {
- .mesa = _NEW_TRANSFORM,
- .brw = BRW_NEW_CONTEXT,
- .cache = 0
+ .mesa = _NEW_BUFFERS |
+ _NEW_LIGHT |
+ _NEW_TRANSFORM,
+ .brw = BRW_NEW_CONTEXT |
+ BRW_NEW_FS_PROG_DATA |
+ BRW_NEW_META_IN_PROGRESS |
+ BRW_NEW_RASTERIZER_DISCARD,
+ },
+ .emit = upload_clip_state,
+};
+
+const struct brw_tracked_state gen7_clip_state = {
+ .dirty = {
+ .mesa = _NEW_BUFFERS |
+ _NEW_LIGHT |
+ _NEW_POLYGON |
+ _NEW_TRANSFORM,
+ .brw = BRW_NEW_CONTEXT |
+ BRW_NEW_FS_PROG_DATA |
+ BRW_NEW_META_IN_PROGRESS |
+ BRW_NEW_RASTERIZER_DISCARD,
},
.emit = upload_clip_state,
};