i965: fix inverted point sprite origin when rendering to FBO

When rendering to FBO, rendering is inverted. At the same time, we would
also make sure the point sprite origin is inverted. Or, we will get an
inverted result correspoinding to rendering to the default winsys FBO.

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=44613

NOTE: This is a candidate for stable release branches.

v2: add the simliar logic to ivb, too (comments from Ian)
    simplify the logic operation (comments from Brian)

v3: pick a better comment from Eric
    use != for the logic instead of ^ (comments from Ian)

Signed-off-by: Yuanhan Liu <yuanhan.liu@linux.intel.com>
Reviewed-by: Ian Romanick <ian.d.romanick@intel.com>
Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>

diff --git a/src/mesa/drivers/dri/i965/brw_defines.h b/src/mesa/drivers/dri/i965/brw_defines.h
index 4d90a99442a5e1b045f7b6027a63a1b01e030db7..029be872d776ef79c04785bdee8745efb86547a6 100644 (file)
--- a/src/mesa/drivers/dri/i965/brw_defines.h
+++ b/src/mesa/drivers/dri/i965/brw_defines.h
@@ -1128,6 +1128,7 @@ enum brw_message_target {
 /* DW1 (for gen6) */
 # define GEN6_SF_NUM_OUTPUTS_SHIFT                     22
 # define GEN6_SF_SWIZZLE_ENABLE                                (1 << 21)
+# define GEN6_SF_POINT_SPRITE_UPPERLEFT                        (0 << 20)
 # define GEN6_SF_POINT_SPRITE_LOWERLEFT                        (1 << 20)
 # define GEN6_SF_URB_ENTRY_READ_LENGTH_SHIFT           11
 # define GEN6_SF_URB_ENTRY_READ_OFFSET_SHIFT           4

diff --git a/src/mesa/drivers/dri/i965/gen6_sf_state.c b/src/mesa/drivers/dri/i965/gen6_sf_state.c
index 548c5a397cc8486ba333d8e40317f2e53f033804..163b54c355794c84346433bc3723ee9e84f847ab 100644 (file)
--- a/src/mesa/drivers/dri/i965/gen6_sf_state.c
+++ b/src/mesa/drivers/dri/i965/gen6_sf_state.c
@@ -129,6 +129,7 @@ upload_sf_state(struct brw_context *brw)
    float point_size;
    uint16_t attr_overrides[FRAG_ATTRIB_MAX];
    bool userclip_active;
+   uint32_t point_sprite_origin;
 
    /* _NEW_TRANSFORM */
    userclip_active = (ctx->Transform.ClipPlanesEnabled != 0);
@@ -258,8 +259,16 @@ upload_sf_state(struct brw_context *brw)
    /* Clamp to the hardware limits and convert to fixed point */
    dw4 |= U_FIXED(CLAMP(point_size, 0.125, 255.875), 3);
 
-   if (ctx->Point.SpriteOrigin == GL_LOWER_LEFT)
-      dw1 |= GEN6_SF_POINT_SPRITE_LOWERLEFT;
+   /*
+    * Window coordinates in an FBO are inverted, which means point
+    * sprite origin must be inverted, too.
+    */
+   if ((ctx->Point.SpriteOrigin == GL_LOWER_LEFT) != render_to_fbo) {
+      point_sprite_origin = GEN6_SF_POINT_SPRITE_LOWERLEFT;
+   } else {
+      point_sprite_origin = GEN6_SF_POINT_SPRITE_UPPERLEFT;
+   }
+   dw1 |= point_sprite_origin;
 
    /* _NEW_LIGHT */
    if (ctx->Light.ProvokingVertex != GL_FIRST_VERTEX_CONVENTION) {

diff --git a/src/mesa/drivers/dri/i965/gen7_sf_state.c b/src/mesa/drivers/dri/i965/gen7_sf_state.c
index 7691cb218d69807bcd0918ae495eca50575b0d14..da7ef81cddffd4bcb26e265f167a8d5d3fd3de35 100644 (file)
--- a/src/mesa/drivers/dri/i965/gen7_sf_state.c
+++ b/src/mesa/drivers/dri/i965/gen7_sf_state.c
@@ -48,6 +48,9 @@ upload_sbe_state(struct brw_context *brw)
    int urb_entry_read_offset = 1;
    bool userclip_active = (ctx->Transform.ClipPlanesEnabled != 0);
    uint16_t attr_overrides[FRAG_ATTRIB_MAX];
+   /* _NEW_BUFFERS */
+   bool render_to_fbo = ctx->DrawBuffer->Name != 0;
+   uint32_t point_sprite_origin;
 
    brw_compute_vue_map(&vue_map, intel, userclip_active, vs_outputs_written);
    urb_entry_read_length = (vue_map.num_slots + 1)/2 - urb_entry_read_offset;
@@ -65,9 +68,18 @@ upload_sbe_state(struct brw_context *brw)
       urb_entry_read_length << GEN7_SBE_URB_ENTRY_READ_LENGTH_SHIFT |
       urb_entry_read_offset << GEN7_SBE_URB_ENTRY_READ_OFFSET_SHIFT;
 
-   /* _NEW_POINT */
-   if (ctx->Point.SpriteOrigin == GL_LOWER_LEFT)
-      dw1 |= GEN6_SF_POINT_SPRITE_LOWERLEFT;
+   /* _NEW_POINT
+    *
+    * Window coordinates in an FBO are inverted, which means point
+    * sprite origin must be inverted.
+    */
+   if ((ctx->Point.SpriteOrigin == GL_LOWER_LEFT) != render_to_fbo) {
+      point_sprite_origin = GEN6_SF_POINT_SPRITE_LOWERLEFT;
+   } else {
+      point_sprite_origin = GEN6_SF_POINT_SPRITE_UPPERLEFT;
+   }
+   dw1 |= point_sprite_origin;
+
 
    dw10 = 0;
    dw11 = 0;