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 #include "main/framebuffer.h"
  34 #include "main/viewport.h"
  35
  36 /* The clip VP defines the guardband region where expensive clipping is skipped
  37  * and fragments are allowed to be generated and clipped out cheaply by the SF.
  38  */
  39 static void
  40 gen6_upload_clip_vp(struct brw_context *brw)
  41 {
  42    struct gl_context *ctx = &brw->ctx;
  43    struct brw_clipper_viewport *vp;
  44
  45    vp = brw_state_batch(brw, AUB_TRACE_CLIP_VP_STATE,
  46                         sizeof(*vp) * ctx->Const.MaxViewports, 32, &brw->clip.vp_offset);
  47
  48    for (unsigned i = 0; i < ctx->Const.MaxViewports; i++) {
  49       /* According to the "Vertex X,Y Clamping and Quantization" section of the
  50        * Strips and Fans documentation, objects must not have a screen-space
  51        * extents of over 8192 pixels, or they may be mis-rasterized.  The maximum
  52        * screen space coordinates of a small object may larger, but we have no
  53        * way to enforce the object size other than through clipping.
  54        *
  55        * If you're surprised that we set clip to -gbx to +gbx and it seems like
  56        * we'll end up with 16384 wide, note that for a 8192-wide render target,
  57        * we'll end up with a normal (-1, 1) clip volume that just covers the
  58        * drawable.
  59        */
  60       const float maximum_post_clamp_delta = 8192;
  61       float gbx = maximum_post_clamp_delta / ctx->ViewportArray[i].Width;
  62       float gby = maximum_post_clamp_delta / ctx->ViewportArray[i].Height;
  63
  64       vp[i].xmin = -gbx;
  65       vp[i].xmax = gbx;
  66       vp[i].ymin = -gby;
  67       vp[i].ymax = gby;
  68    }
  69
  70    brw->ctx.NewDriverState |= BRW_NEW_CLIP_VP;
  71 }
  72
  73 const struct brw_tracked_state gen6_clip_vp = {
  74    .dirty = {
  75       .mesa = _NEW_VIEWPORT,
  76       .brw = BRW_NEW_BATCH,
  77    },
  78    .emit = gen6_upload_clip_vp,
  79 };
  80
  81 static void
  82 gen6_upload_sf_vp(struct brw_context *brw)
  83 {
  84    struct gl_context *ctx = &brw->ctx;
  85    struct gen6_sf_viewport *sfv;
  86    GLfloat y_scale, y_bias;
  87    const bool render_to_fbo = _mesa_is_user_fbo(ctx->DrawBuffer);
  88
  89    sfv = brw_state_batch(brw, AUB_TRACE_SF_VP_STATE,
  90                          sizeof(*sfv) * ctx->Const.MaxViewports,
  91                          32, &brw->sf.vp_offset);
  92    memset(sfv, 0, sizeof(*sfv) * ctx->Const.MaxViewports);
  93
  94    /* _NEW_BUFFERS */
  95    if (render_to_fbo) {
  96       y_scale = 1.0;
  97       y_bias = 0.0;
  98    } else {
  99       y_scale = -1.0;
 100       y_bias = (float)_mesa_geometric_height(ctx->DrawBuffer);
 101    }
 102
 103    for (unsigned i = 0; i < ctx->Const.MaxViewports; i++) {
 104       float scale[3], translate[3];
 105
 106       /* _NEW_VIEWPORT */
 107       _mesa_get_viewport_xform(ctx, i, scale, translate);
 108       sfv[i].m00 = scale[0];
 109       sfv[i].m11 = scale[1] * y_scale;
 110       sfv[i].m22 = scale[2];
 111       sfv[i].m30 = translate[0];
 112       sfv[i].m31 = translate[1] * y_scale + y_bias;
 113       sfv[i].m32 = translate[2];
 114
 115    }
 116
 117    brw->ctx.NewDriverState |= BRW_NEW_SF_VP;
 118 }
 119
 120 const struct brw_tracked_state gen6_sf_vp = {
 121    .dirty = {
 122       .mesa = _NEW_BUFFERS |
 123               _NEW_VIEWPORT,
 124       .brw = BRW_NEW_BATCH,
 125    },
 126    .emit = gen6_upload_sf_vp,
 127 };
 128
 129 static void upload_viewport_state_pointers(struct brw_context *brw)
 130 {
 131    BEGIN_BATCH(4);
 132    OUT_BATCH(_3DSTATE_VIEWPORT_STATE_POINTERS << 16 | (4 - 2) |
 133              GEN6_CC_VIEWPORT_MODIFY |
 134              GEN6_SF_VIEWPORT_MODIFY |
 135              GEN6_CLIP_VIEWPORT_MODIFY);
 136    OUT_BATCH(brw->clip.vp_offset);
 137    OUT_BATCH(brw->sf.vp_offset);
 138    OUT_BATCH(brw->cc.vp_offset);
 139    ADVANCE_BATCH();
 140 }
 141
 142 const struct brw_tracked_state gen6_viewport_state = {
 143    .dirty = {
 144       .mesa = 0,
 145       .brw = BRW_NEW_BATCH |
 146              BRW_NEW_CC_VP |
 147              BRW_NEW_CLIP_VP |
 148              BRW_NEW_SF_VP |
 149              BRW_NEW_STATE_BASE_ADDRESS,
 150    },
 151    .emit = upload_viewport_state_pointers,
 152 };