src/mesa/drivers/dri/i965/gen6_viewport_state.c

   1 /*
   2  * Copyright © 2009 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  *    Eric Anholt <eric@anholt.net>
  25  *
  26  */
  27
  28 #include "brw_context.h"
  29 #include "brw_state.h"
  30 #include "brw_defines.h"
  31 #include "intel_batchbuffer.h"
  32 #include "main/fbobject.h"
  33
  34 /* The clip VP defines the guardband region where expensive clipping is skipped
  35  * and fragments are allowed to be generated and clipped out cheaply by the SF.
  36  */
  37 static void
  38 gen6_upload_clip_vp(struct brw_context *brw)
  39 {
  40    struct gl_context *ctx = &brw->intel.ctx;
  41    struct brw_clipper_viewport *vp;
  42
  43    vp = brw_state_batch(brw, AUB_TRACE_CLIP_VP_STATE,
  44                         sizeof(*vp), 32, &brw->clip.vp_offset);
  45
  46    /* According to the Sandybridge PRM, Volume 2, Part 1, Section 6.3.8
  47     * "Vertex X,Y Clamping and Quantization", the screen-aligned 2D
  48     * bounding-box of an object must not exceed 16K pixels in either X or Y.
  49     */
  50    const float maximum_post_clamp_delta = 16384;
  51    float gbx = maximum_post_clamp_delta / (float) ctx->Viewport.Width;
  52    float gby = maximum_post_clamp_delta / (float) ctx->Viewport.Height;
  53
  54    vp->xmin = -gbx;
  55    vp->xmax = gbx;
  56    vp->ymin = -gby;
  57    vp->ymax = gby;
  58
  59    brw->state.dirty.cache |= CACHE_NEW_CLIP_VP;
  60 }
  61
  62 const struct brw_tracked_state gen6_clip_vp = {
  63    .dirty = {
  64       .mesa = _NEW_VIEWPORT,
  65       .brw = BRW_NEW_BATCH,
  66       .cache = 0,
  67    },
  68    .emit = gen6_upload_clip_vp,
  69 };
  70
  71 static void
  72 gen6_upload_sf_vp(struct brw_context *brw)
  73 {
  74    struct gl_context *ctx = &brw->intel.ctx;
  75    const GLfloat depth_scale = 1.0F / ctx->DrawBuffer->_DepthMaxF;
  76    struct brw_sf_viewport *sfv;
  77    GLfloat y_scale, y_bias;
  78    const bool render_to_fbo = _mesa_is_user_fbo(ctx->DrawBuffer);
  79    const GLfloat *v = ctx->Viewport._WindowMap.m;
  80
  81    sfv = brw_state_batch(brw, AUB_TRACE_SF_VP_STATE,
  82                          sizeof(*sfv), 32, &brw->sf.vp_offset);
  83    memset(sfv, 0, sizeof(*sfv));
  84
  85    /* _NEW_BUFFERS */
  86    if (render_to_fbo) {
  87       y_scale = 1.0;
  88       y_bias = 0;
  89    } else {
  90       y_scale = -1.0;
  91       y_bias = ctx->DrawBuffer->Height;
  92    }
  93
  94    /* _NEW_VIEWPORT */
  95    sfv->viewport.m00 = v[MAT_SX];
  96    sfv->viewport.m11 = v[MAT_SY] * y_scale;
  97    sfv->viewport.m22 = v[MAT_SZ] * depth_scale;
  98    sfv->viewport.m30 = v[MAT_TX];
  99    sfv->viewport.m31 = v[MAT_TY] * y_scale + y_bias;
 100    sfv->viewport.m32 = v[MAT_TZ] * depth_scale;
 101
 102    brw->state.dirty.cache |= CACHE_NEW_SF_VP;
 103 }
 104
 105 const struct brw_tracked_state gen6_sf_vp = {
 106    .dirty = {
 107       .mesa = _NEW_VIEWPORT | _NEW_BUFFERS,
 108       .brw = BRW_NEW_BATCH,
 109       .cache = 0,
 110    },
 111    .emit = gen6_upload_sf_vp,
 112 };
 113
 114 static void upload_viewport_state_pointers(struct brw_context *brw)
 115 {
 116    struct intel_context *intel = &brw->intel;
 117
 118    BEGIN_BATCH(4);
 119    OUT_BATCH(_3DSTATE_VIEWPORT_STATE_POINTERS << 16 | (4 - 2) |
 120              GEN6_CC_VIEWPORT_MODIFY |
 121              GEN6_SF_VIEWPORT_MODIFY |
 122              GEN6_CLIP_VIEWPORT_MODIFY);
 123    OUT_BATCH(brw->clip.vp_offset);
 124    OUT_BATCH(brw->sf.vp_offset);
 125    OUT_BATCH(brw->cc.vp_offset);
 126    ADVANCE_BATCH();
 127 }
 128
 129 const struct brw_tracked_state gen6_viewport_state = {
 130    .dirty = {
 131       .mesa = 0,
 132       .brw = (BRW_NEW_BATCH |
 133               BRW_NEW_STATE_BASE_ADDRESS),
 134       .cache = (CACHE_NEW_CLIP_VP |
 135                 CACHE_NEW_SF_VP |
 136                 CACHE_NEW_CC_VP)
 137    },
 138    .emit = upload_viewport_state_pointers,
 139 };