Merge remote-tracking branch 'mesa-public/master' into vulkan

[mesa.git] / src / mesa / drivers / dri / i965 / gen6_clip_state.c

diff --git a/src/mesa/drivers/dri/i965/gen6_clip_state.c b/src/mesa/drivers/dri/i965/gen6_clip_state.c
index e8c1b915172cc1d00ce0de721aad2e057dfca308..9a29366f0e0de8bfa83df326f8bdf5b4703b5977 100644 (file)
--- a/src/mesa/drivers/dri/i965/gen6_clip_state.c
+++ b/src/mesa/drivers/dri/i965/gen6_clip_state.c
@@ -31,6 +31,7 @@
 #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)
@@ -43,7 +44,7 @@ upload_clip_state(struct brw_context *brw)
    /* _NEW_BUFFERS */
    struct gl_framebuffer *fb = ctx->DrawBuffer;
 
-   /* CACHE_NEW_WM_PROG */
+   /* 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;
@@ -54,7 +55,7 @@ upload_clip_state(struct brw_context *brw)
 
    if (brw->gen == 7) {
       /* _NEW_POLYGON */
-      if ((ctx->Polygon.FrontFace == GL_CCW) ^ _mesa_is_user_fbo(fb))
+      if (ctx->Polygon._FrontBit == _mesa_is_user_fbo(fb))
          dw1 |= GEN7_CLIP_WINDING_CCW;
 
       if (ctx->Polygon.CullFlag) {
@@ -95,9 +96,44 @@ upload_clip_state(struct brw_context *brw)
    /* _NEW_TRANSFORM */
    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
@@ -110,11 +146,14 @@ upload_clip_state(struct brw_context *brw)
     * 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 != (float) fb->Width ||
-             ctx->ViewportArray[i].Height != (float) fb->Height) {
+             ctx->ViewportArray[i].Width != fb_width ||
+             ctx->ViewportArray[i].Height != fb_height) {
             dw2 &= ~GEN6_CLIP_GB_TEST;
             break;
          }
@@ -139,35 +178,39 @@ upload_clip_state(struct brw_context *brw)
    OUT_BATCH(_3DSTATE_CLIP << 16 | (4 - 2));
    OUT_BATCH(dw1);
    OUT_BATCH(enable |
-            GEN6_CLIP_API_OGL |
             GEN6_CLIP_MODE_NORMAL |
             GEN6_CLIP_XY_TEST |
             dw2);
    OUT_BATCH(U_FIXED(0.125, 3) << GEN6_CLIP_MIN_POINT_WIDTH_SHIFT |
              U_FIXED(255.875, 3) << GEN6_CLIP_MAX_POINT_WIDTH_SHIFT |
-             (fb->MaxNumLayers > 0 ? 0 : GEN6_CLIP_FORCE_ZERO_RTAINDEX) |
+             (_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 | _NEW_LIGHT | _NEW_BUFFERS,
+      .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,
-      .cache = CACHE_NEW_WM_PROG
    },
    .emit = upload_clip_state,
 };
 
 const struct brw_tracked_state gen7_clip_state = {
    .dirty = {
-      .mesa  = _NEW_BUFFERS | _NEW_LIGHT | _NEW_POLYGON | _NEW_TRANSFORM,
+      .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,
-      .cache = CACHE_NEW_WM_PROG
    },
    .emit = upload_clip_state,
 };