2 * Copyright © 2011 Intel Corporation
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:
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
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
24 #include "brw_context.h"
25 #include "brw_state.h"
26 #include "brw_defines.h"
27 #include "intel_batchbuffer.h"
28 #include "main/fbobject.h"
31 gen8_upload_sf_clip_viewport(struct brw_context
*brw
)
33 struct gl_context
*ctx
= &brw
->ctx
;
34 const GLfloat depth_scale
= 1.0F
/ ctx
->DrawBuffer
->_DepthMaxF
;
35 float y_scale
, y_bias
;
36 const bool render_to_fbo
= _mesa_is_user_fbo(ctx
->DrawBuffer
);
38 float *vp
= brw_state_batch(brw
, AUB_TRACE_SF_VP_STATE
,
39 16 * 4 * ctx
->Const
.MaxViewports
,
40 64, &brw
->sf
.vp_offset
);
41 /* Also assign to clip.vp_offset in case something uses it. */
42 brw
->clip
.vp_offset
= brw
->sf
.vp_offset
;
50 y_bias
= ctx
->DrawBuffer
->Height
;
53 for (unsigned i
= 0; i
< ctx
->Const
.MaxViewports
; i
++) {
54 const GLfloat
*const v
= ctx
->ViewportArray
[i
]._WindowMap
.m
;
56 /* _NEW_VIEWPORT: Viewport Matrix Elements */
57 vp
[0] = v
[MAT_SX
]; /* m00 */
58 vp
[1] = v
[MAT_SY
] * y_scale
; /* m11 */
59 vp
[2] = v
[MAT_SZ
] * depth_scale
; /* m22 */
60 vp
[3] = v
[MAT_TX
]; /* m30 */
61 vp
[4] = v
[MAT_TY
] * y_scale
+ y_bias
; /* m31 */
62 vp
[5] = v
[MAT_TZ
] * depth_scale
; /* m32 */
68 /* According to the "Vertex X,Y Clamping and Quantization" section of the
69 * Strips and Fans documentation, objects must not have a screen-space
70 * extents of over 8192 pixels, or they may be mis-rasterized. The
71 * maximum screen space coordinates of a small object may larger, but we
72 * have no way to enforce the object size other than through clipping.
74 * The goal is to create the maximum sized guardband (8K x 8K) with the
75 * viewport rectangle in the center of the guardband. This looks weird
76 * because the hardware wants coordinates that are scaled to the viewport
77 * in NDC. In other words, an 8K x 8K viewport would have [-1,1] for X and Y.
78 * A 4K viewport would be [-2,2], 2K := [-4,4] etc.
80 * --------------------------------
90 * |______________________________|
93 const float maximum_guardband_extent
= 8192;
94 float gbx
= maximum_guardband_extent
/ ctx
->ViewportArray
[i
].Width
;
95 float gby
= maximum_guardband_extent
/ ctx
->ViewportArray
[i
].Height
;
97 /* _NEW_VIEWPORT: Guardband Clipping */
98 vp
[8] = -gbx
; /* x-min */
99 vp
[9] = gbx
; /* x-max */
100 vp
[10] = -gby
; /* y-min */
101 vp
[11] = gby
; /* y-max */
103 /* _NEW_VIEWPORT | _NEW_BUFFERS: Screen Space Viewport
104 * The hardware will take the intersection of the drawing rectangle,
105 * scissor rectangle, and the viewport extents. We don't need to be
106 * smart, and can therefore just program the viewport extents.
108 float viewport_Xmax
= ctx
->ViewportArray
[i
].X
+ ctx
->ViewportArray
[i
].Width
;
109 float viewport_Ymax
= ctx
->ViewportArray
[i
].Y
+ ctx
->ViewportArray
[i
].Height
;
111 vp
[12] = ctx
->ViewportArray
[i
].X
;
112 vp
[13] = viewport_Xmax
- 1;
113 vp
[14] = ctx
->ViewportArray
[i
].Y
;
114 vp
[15] = viewport_Ymax
- 1;
116 vp
[12] = ctx
->ViewportArray
[i
].X
;
117 vp
[13] = viewport_Xmax
- 1;
118 vp
[14] = ctx
->DrawBuffer
->Height
- viewport_Ymax
;
119 vp
[15] = ctx
->DrawBuffer
->Height
- ctx
->ViewportArray
[i
].Y
- 1;
126 OUT_BATCH(_3DSTATE_VIEWPORT_STATE_POINTERS_SF_CL
<< 16 | (2 - 2));
127 OUT_BATCH(brw
->sf
.vp_offset
);
131 const struct brw_tracked_state gen8_sf_clip_viewport
= {
133 .mesa
= _NEW_BUFFERS
| _NEW_VIEWPORT
,
134 .brw
= BRW_NEW_BATCH
,
137 .emit
= gen8_upload_sf_clip_viewport
,