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