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
  33 /* The clip VP defines the guardband region where expensive clipping is skipped
  34  * and fragments are allowed to be generated and clipped out cheaply by the SF.
  35  *
  36  * By setting it to NDC bounds of [-1,1], we don't do GB clipping.  It's
  37  * supposed to cause seams to become visible in apps due to shared edges taking
  38  * different clip/no clip paths depending on whether the rest of the prim ends
  39  * up in the guardband or not.
  40  */
  41 static void
  42 prepare_clip_vp(struct brw_context *brw)
  43 {
  44    struct brw_clipper_viewport *vp;
  45
  46    vp = brw_state_batch(brw, sizeof(*vp), 32, &brw->clip.vp_offset);
  47
  48    vp->xmin = -1.0;
  49    vp->xmax = 1.0;
  50    vp->ymin = -1.0;
  51    vp->ymax = 1.0;
  52
  53    brw->state.dirty.cache |= CACHE_NEW_CLIP_VP;
  54 }
  55
  56 const struct brw_tracked_state gen6_clip_vp = {
  57    .dirty = {
  58       .mesa = 0,
  59       .brw = BRW_NEW_BATCH,
  60       .cache = 0,
  61    },
  62    .prepare = prepare_clip_vp,
  63 };
  64
  65 static void
  66 prepare_sf_vp(struct brw_context *brw)
  67 {
  68    struct gl_context *ctx = &brw->intel.ctx;
  69    const GLfloat depth_scale = 1.0F / ctx->DrawBuffer->_DepthMaxF;
  70    struct brw_sf_viewport *sfv;
  71    GLfloat y_scale, y_bias;
  72    const GLboolean render_to_fbo = (ctx->DrawBuffer->Name != 0);
  73    const GLfloat *v = ctx->Viewport._WindowMap.m;
  74
  75    sfv = brw_state_batch(brw, sizeof(*sfv), 32, &brw->sf.vp_offset);
  76    memset(sfv, 0, sizeof(*sfv));
  77
  78    /* _NEW_BUFFERS */
  79    if (render_to_fbo) {
  80       y_scale = 1.0;
  81       y_bias = 0;
  82    } else {
  83       y_scale = -1.0;
  84       y_bias = ctx->DrawBuffer->Height;
  85    }
  86
  87    /* _NEW_VIEWPORT */
  88    sfv->viewport.m00 = v[MAT_SX];
  89    sfv->viewport.m11 = v[MAT_SY] * y_scale;
  90    sfv->viewport.m22 = v[MAT_SZ] * depth_scale;
  91    sfv->viewport.m30 = v[MAT_TX];
  92    sfv->viewport.m31 = v[MAT_TY] * y_scale + y_bias;
  93    sfv->viewport.m32 = v[MAT_TZ] * depth_scale;
  94
  95    brw->state.dirty.cache |= CACHE_NEW_SF_VP;
  96 }
  97
  98 const struct brw_tracked_state gen6_sf_vp = {
  99    .dirty = {
 100       .mesa = _NEW_VIEWPORT | _NEW_BUFFERS,
 101       .brw = BRW_NEW_BATCH,
 102       .cache = 0,
 103    },
 104    .prepare = prepare_sf_vp,
 105 };
 106
 107 static void upload_viewport_state_pointers(struct brw_context *brw)
 108 {
 109    struct intel_context *intel = &brw->intel;
 110
 111    BEGIN_BATCH(4);
 112    OUT_BATCH(_3DSTATE_VIEWPORT_STATE_POINTERS << 16 | (4 - 2) |
 113              GEN6_CC_VIEWPORT_MODIFY |
 114              GEN6_SF_VIEWPORT_MODIFY |
 115              GEN6_CLIP_VIEWPORT_MODIFY);
 116    OUT_BATCH(brw->clip.vp_offset);
 117    OUT_BATCH(brw->sf.vp_offset);
 118    OUT_BATCH(brw->cc.vp_offset);
 119    ADVANCE_BATCH();
 120 }
 121
 122 const struct brw_tracked_state gen6_viewport_state = {
 123    .dirty = {
 124       .mesa = 0,
 125       .brw = (BRW_NEW_BATCH |
 126               BRW_NEW_STATE_BASE_ADDRESS),
 127       .cache = (CACHE_NEW_CLIP_VP |
 128                 CACHE_NEW_SF_VP |
 129                 CACHE_NEW_CC_VP)
 130    },
 131    .emit = upload_viewport_state_pointers,
 132 };