src/mesa/drivers/dri/i965/brw_primitive_restart.c

   1 /*
   2  * Copyright © 2012 Intel Corporation
   3  *
   4  * Permission is hereby granted, free of charge, to any person obtaining a
   5  * copy of this software and associated documentation files (the "Software"),
   6  * to deal in the Software without restriction, including without limitation
   7  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
   8  * and/or sell copies of the Software, and to permit persons to whom the
   9  * Software is furnished to do so, subject to the following conditions:
  10  *
  11  * The above copyright notice and this permission notice (including the next
  12  * paragraph) shall be included in all copies or substantial portions of the
  13  * Software.
  14  *
  15  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  16  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  17  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  18  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  19  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
  20  * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
  21  * IN THE SOFTWARE.
  22  *
  23  * Authors:
  24  *    Jordan Justen <jordan.l.justen@intel.com>
  25  *
  26  */
  27
  28 #include "main/imports.h"
  29 #include "main/bufferobj.h"
  30
  31 #include "brw_context.h"
  32 #include "brw_defines.h"
  33 #include "brw_draw.h"
  34
  35 #include "intel_batchbuffer.h"
  36
  37 /**
  38  * Check if the hardware's cut index support can handle the primitive
  39  * restart index value.
  40  */
  41 static bool
  42 can_cut_index_handle_restart_index(struct gl_context *ctx,
  43                                    const struct _mesa_index_buffer *ib)
  44 {
  45    struct intel_context *intel = intel_context(ctx);
  46
  47    /* Haswell supports an arbitrary cut index. */
  48    if (intel->is_haswell)
  49       return true;
  50
  51    bool cut_index_will_work;
  52
  53    switch (ib->type) {
  54    case GL_UNSIGNED_BYTE:
  55       cut_index_will_work = (ctx->Array._RestartIndex & 0xff) == 0xff;
  56       break;
  57    case GL_UNSIGNED_SHORT:
  58       cut_index_will_work = (ctx->Array._RestartIndex & 0xffff) == 0xffff;
  59       break;
  60    case GL_UNSIGNED_INT:
  61       cut_index_will_work = ctx->Array._RestartIndex == 0xffffffff;
  62       break;
  63    default:
  64       cut_index_will_work = false;
  65       assert(0);
  66    }
  67
  68    return cut_index_will_work;
  69 }
  70
  71 /**
  72  * Check if the hardware's cut index support can handle the primitive
  73  * restart case.
  74  */
  75 static bool
  76 can_cut_index_handle_prims(struct gl_context *ctx,
  77                            const struct _mesa_prim *prim,
  78                            GLuint nr_prims,
  79                            const struct _mesa_index_buffer *ib)
  80 {
  81    struct brw_context *brw = brw_context(ctx);
  82
  83    if (brw->sol.counting_primitives_generated ||
  84        brw->sol.counting_primitives_written) {
  85       /* Counting primitives generated in hardware is not currently
  86        * supported, so take the software path. We need to investigate
  87        * the *_PRIMITIVES_COUNT registers to allow this to be handled
  88        * entirely in hardware.
  89        */
  90       return false;
  91    }
  92
  93    if (!can_cut_index_handle_restart_index(ctx, ib)) {
  94       /* The primitive restart index can't be handled, so take
  95        * the software path
  96        */
  97       return false;
  98    }
  99
 100    for ( ; nr_prims > 0; nr_prims--) {
 101       switch(prim->mode) {
 102       case GL_POINTS:
 103       case GL_LINES:
 104       case GL_LINE_STRIP:
 105       case GL_TRIANGLES:
 106       case GL_TRIANGLE_STRIP:
 107          /* Cut index supports these primitive types */
 108          break;
 109       default:
 110          /* Cut index does not support these primitive types */
 111       //case GL_LINE_LOOP:
 112       //case GL_TRIANGLE_FAN:
 113       //case GL_QUADS:
 114       //case GL_QUAD_STRIP:
 115       //case GL_POLYGON:
 116          return false;
 117       }
 118    }
 119
 120    return true;
 121 }
 122
 123 /**
 124  * Check if primitive restart is enabled, and if so, handle it properly.
 125  *
 126  * In some cases the support will be handled in software. When available
 127  * hardware will handle primitive restart.
 128  */
 129 GLboolean
 130 brw_handle_primitive_restart(struct gl_context *ctx,
 131                              const struct _mesa_prim *prim,
 132                              GLuint nr_prims,
 133                              const struct _mesa_index_buffer *ib)
 134 {
 135    struct brw_context *brw = brw_context(ctx);
 136
 137    /* We only need to handle cases where there is an index buffer. */
 138    if (ib == NULL) {
 139       return GL_FALSE;
 140    }
 141
 142    /* If the driver has requested software handling of primitive restarts,
 143     * then the VBO module has already taken care of things, and we can
 144     * just draw as normal.
 145     */
 146    if (ctx->Const.PrimitiveRestartInSoftware) {
 147       return GL_FALSE;
 148    }
 149
 150    /* If we have set the in_progress flag, then we are in the middle
 151     * of handling the primitive restart draw.
 152     */
 153    if (brw->prim_restart.in_progress) {
 154       return GL_FALSE;
 155    }
 156
 157    /* If PrimitiveRestart is not enabled, then we aren't concerned about
 158     * handling this draw.
 159     */
 160    if (!(ctx->Array._PrimitiveRestart)) {
 161       return GL_FALSE;
 162    }
 163
 164    /* Signal that we are in the process of handling the
 165     * primitive restart draw
 166     */
 167    brw->prim_restart.in_progress = true;
 168
 169    if (can_cut_index_handle_prims(ctx, prim, nr_prims, ib)) {
 170       /* Cut index should work for primitive restart, so use it
 171        */
 172       brw->prim_restart.enable_cut_index = true;
 173       brw_draw_prims(ctx, prim, nr_prims, ib, GL_FALSE, -1, -1, NULL);
 174       brw->prim_restart.enable_cut_index = false;
 175    } else {
 176       /* Not all the primitive draw modes are supported by the cut index,
 177        * so take the software path
 178        */
 179       vbo_sw_primitive_restart(ctx, prim, nr_prims, ib);
 180    }
 181
 182    brw->prim_restart.in_progress = false;
 183
 184    /* The primitive restart draw was completed, so return true. */
 185    return GL_TRUE;
 186 }
 187
 188 static void
 189 haswell_upload_cut_index(struct brw_context *brw)
 190 {
 191    struct intel_context *intel = &brw->intel;
 192    struct gl_context *ctx = &intel->ctx;
 193
 194    /* Don't trigger on Ivybridge */
 195    if (!intel->is_haswell)
 196       return;
 197
 198    const unsigned cut_index_setting =
 199       ctx->Array.PrimitiveRestart ? HSW_CUT_INDEX_ENABLE : 0;
 200
 201    BEGIN_BATCH(2);
 202    OUT_BATCH(_3DSTATE_VF << 16 | cut_index_setting | (2 - 2));
 203    OUT_BATCH(ctx->Array.RestartIndex);
 204    ADVANCE_BATCH();
 205 }
 206
 207 const struct brw_tracked_state haswell_cut_index = {
 208    .dirty = {
 209       .mesa  = _NEW_TRANSFORM,
 210       .brw   = 0,
 211       .cache = 0,
 212    },
 213    .emit = haswell_upload_cut_index,
 214 };