Commit 43af02ac authored by Yuanhan Liu's avatar Yuanhan Liu
Browse files

i965: handle gl_PointCoord for Gen4 and Gen5 platforms

This patch add the support of gl_PointCoord gl builtin variable for
platform gen4 and gen5(ILK).

Unlike gen6+, we don't have a hardware support of gl_PointCoord, means
hardware will not calculate the interpolation coefficient for you.
Instead, you should handle it yourself in sf shader stage.

But badly, gl_PointCoord is a FS instead of VS builtin variable, thus
it's not included in c.vue_map generated in VS stage. Thus the current
code doesn't aware of this attribute. And to handle it correctly, we
need add it to c.vue_map manually to let SF shader generate the needed
interpolation coefficient for FS shader. SF stage has it's own copy of
vue_map, thus I think it's safe to do it manually.

Since handling gl_PointCoord for gen4 and gen5 platforms is somehow a
little special, I added a lot of comments and hope I didn't overdo it ;)

v2: add a /* _NEW_BUFFERS */ comment to note the state flag dependency
    and also add the _NEW_BUFFERS dirty mask (Eric).

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=45975


Piglit: glsl-fs-pointcoord and fbo-gl_pointcoord

NOTE: This is a candidate for stable release branches.
Signed-off-by: Yuanhan Liu's avatarYuanhan Liu <yuanhan.liu@linux.intel.com>
Reviewed-by: Emma Anholt's avatarEric Anholt <eric@anholt.net>
parent cf2f9ef0
......@@ -296,6 +296,12 @@ typedef enum
BRW_VERT_RESULT_NDC = VERT_RESULT_MAX,
BRW_VERT_RESULT_HPOS_DUPLICATE,
BRW_VERT_RESULT_PAD,
/*
* It's actually not a vert_result but just a _mark_ to let sf aware that
* he need do something special to handle gl_PointCoord builtin variable
* correctly. see compile_sf_prog() for more info.
*/
BRW_VERT_RESULT_PNTC,
BRW_VERT_RESULT_MAX
} brw_vert_result;
......
......@@ -710,6 +710,15 @@ fs_visitor::calculate_urb_setup()
urb_setup[fp_index] = urb_next++;
}
}
/*
* It's a FS only attribute, and we did interpolation for this attribute
* in SF thread. So, count it here, too.
*
* See compile_sf_prog() for more info.
*/
if (brw->fragment_program->Base.InputsRead & BITFIELD64_BIT(FRAG_ATTRIB_PNTC))
urb_setup[FRAG_ATTRIB_PNTC] = urb_next++;
}
/* Each attribute is 4 setup channels, each of which is half a reg. */
......
......@@ -64,6 +64,16 @@ static void compile_sf_prog( struct brw_context *brw,
c.key = *key;
c.vue_map = brw->vs.prog_data->vue_map;
if (c.key.do_point_coord) {
/*
* gl_PointCoord is a FS instead of VS builtin variable, thus it's
* not included in c.vue_map generated in VS stage. Here we add
* it manually to let SF shader generate the needed interpolation
* coefficient for FS shader.
*/
c.vue_map.vert_result_to_slot[BRW_VERT_RESULT_PNTC] = c.vue_map.num_slots;
c.vue_map.slot_to_vert_result[c.vue_map.num_slots++] = BRW_VERT_RESULT_PNTC;
}
c.urb_entry_read_offset = brw_sf_compute_urb_entry_read_offset(intel);
c.nr_attr_regs = (c.vue_map.num_slots + 1)/2 - c.urb_entry_read_offset;
c.nr_setup_regs = c.nr_attr_regs;
......@@ -125,6 +135,8 @@ brw_upload_sf_prog(struct brw_context *brw)
{
struct gl_context *ctx = &brw->intel.ctx;
struct brw_sf_prog_key key;
/* _NEW_BUFFERS */
bool render_to_fbo = ctx->DrawBuffer->Name != 0;
memset(&key, 0, sizeof(key));
......@@ -167,7 +179,15 @@ brw_upload_sf_prog(struct brw_context *brw)
key.point_sprite_coord_replace |= (1 << i);
}
}
key.sprite_origin_lower_left = (ctx->Point.SpriteOrigin == GL_LOWER_LEFT);
if (brw->fragment_program->Base.InputsRead & BITFIELD64_BIT(FRAG_ATTRIB_PNTC))
key.do_point_coord = 1;
/*
* Window coordinates in a FBO are inverted, which means point
* sprite origin must be inverted, too.
*/
if ((ctx->Point.SpriteOrigin == GL_LOWER_LEFT) != render_to_fbo)
key.sprite_origin_lower_left = true;
/* _NEW_LIGHT */
key.do_flat_shading = (ctx->Light.ShadeModel == GL_FLAT);
key.do_twoside_color = (ctx->Light.Enabled && ctx->Light.Model.TwoSide);
......@@ -176,10 +196,9 @@ brw_upload_sf_prog(struct brw_context *brw)
if (key.do_twoside_color) {
/* If we're rendering to a FBO, we have to invert the polygon
* face orientation, just as we invert the viewport in
* sf_unit_create_from_key(). ctx->DrawBuffer->Name will be
* nonzero if we're rendering to such an FBO.
* sf_unit_create_from_key().
*/
key.frontface_ccw = (ctx->Polygon.FrontFace == GL_CCW) ^ (ctx->DrawBuffer->Name != 0);
key.frontface_ccw = (ctx->Polygon.FrontFace == GL_CCW) != render_to_fbo;
}
if (!brw_search_cache(&brw->cache, BRW_SF_PROG,
......@@ -192,7 +211,8 @@ brw_upload_sf_prog(struct brw_context *brw)
const struct brw_tracked_state brw_sf_prog = {
.dirty = {
.mesa = (_NEW_HINT | _NEW_LIGHT | _NEW_POLYGON | _NEW_POINT | _NEW_TRANSFORM),
.mesa = (_NEW_HINT | _NEW_LIGHT | _NEW_POLYGON | _NEW_POINT |
_NEW_TRANSFORM | _NEW_BUFFERS),
.brw = (BRW_NEW_REDUCED_PRIMITIVE),
.cache = CACHE_NEW_VS_PROG
},
......
......@@ -52,6 +52,7 @@ struct brw_sf_prog_key {
GLuint do_flat_shading:1;
GLuint frontface_ccw:1;
GLuint do_point_sprite:1;
GLuint do_point_coord:1;
GLuint sprite_origin_lower_left:1;
GLuint userclip_active:1;
};
......
......@@ -386,6 +386,8 @@ calculate_point_sprite_mask(struct brw_sf_compile *c, GLuint reg)
if (c->key.point_sprite_coord_replace & (1 << (vert_result1 - VERT_RESULT_TEX0)))
pc |= 0x0f;
}
if (vert_result1 == BRW_VERT_RESULT_PNTC)
pc |= 0x0f;
vert_result2 = vert_reg_to_vert_result(c, reg, 1);
if (vert_result2 >= VERT_RESULT_TEX0 && vert_result2 <= VERT_RESULT_TEX7) {
......@@ -393,6 +395,8 @@ calculate_point_sprite_mask(struct brw_sf_compile *c, GLuint reg)
VERT_RESULT_TEX0)))
pc |= 0xf0;
}
if (vert_result2 == BRW_VERT_RESULT_PNTC)
pc |= 0xf0;
return pc;
}
......
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