mesa,gallium: Revert "Make point coord origin a CAP"

This reverts commit e749f67f89, which added a CAP
to support drivers that can only do upside-down point coordinates. That was
added specifically for Asahi, since Metal's point coordinate convention is
opposite Mesa's. Since then, additional reverse-engineering aided by the PowerVR
headers led me to the bit doing the flip in hardware, so Asahi does not use the
CAP since baadc1ec13 ("asahi: Don't use lower_wpos_pntc"). Garbage collect it.

[If it's needed for future hardware, we can revive it. But the plan is Vulkan
anyway.]

Signed-off-by: Alyssa Rosenzweig <alyssa@collabora.com>
Suggested-by: Erik Faye-Lund <erik.faye-lund@collabora.com>
Reviewed-by: Erik Faye-Lund <erik.faye-lund@collabora.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/19078>

docs/gallium/screen.rst

@@ -71,8 +71,6 @@ The integer capabilities:
   pixel-center fragment convention is supported.
 * ``PIPE_CAP_FS_COORD_PIXEL_CENTER_INTEGER``: Whether the integer
   pixel-center fragment convention is supported.
-* ``PIPE_CAP_POINT_COORD_ORIGIN_UPPER_LEFT``: Whether point coordinates use the
-  upper-left origin convention. Otherwise the lower-left convention is used.
 * ``PIPE_CAP_DEPTH_CLIP_DISABLE``: Whether the driver is capable of disabling
   depth clipping (through pipe_rasterizer_state).
 * ``PIPE_CAP_DEPTH_CLIP_DISABLE_SEPARATE``: Whether the driver is capable of

src/gallium/auxiliary/util/u_screen.c

@@ -75,11 +75,6 @@ u_pipe_screen_get_param_defaults(struct pipe_screen *pscreen,
    case PIPE_CAP_FS_COORD_ORIGIN_LOWER_LEFT:
    case PIPE_CAP_FS_COORD_PIXEL_CENTER_HALF_INTEGER:
    case PIPE_CAP_FS_COORD_PIXEL_CENTER_INTEGER:
-      return 0;
-
-   case PIPE_CAP_POINT_COORD_ORIGIN_UPPER_LEFT:
-      return 1;
-
    case PIPE_CAP_DEPTH_CLIP_DISABLE:
    case PIPE_CAP_DEPTH_CLIP_DISABLE_SEPARATE:
    case PIPE_CAP_DEPTH_CLAMP_ENABLE:

src/gallium/drivers/nouveau/nv50/nv50_screen.c

@@ -218,7 +218,6 @@ nv50_screen_get_param(struct pipe_screen *pscreen, enum pipe_cap param)
    case PIPE_CAP_INDEP_BLEND_ENABLE:
    case PIPE_CAP_FS_COORD_ORIGIN_UPPER_LEFT:
    case PIPE_CAP_FS_COORD_PIXEL_CENTER_HALF_INTEGER:
-   case PIPE_CAP_POINT_COORD_ORIGIN_UPPER_LEFT:
    case PIPE_CAP_PRIMITIVE_RESTART:
    case PIPE_CAP_PRIMITIVE_RESTART_FIXED_INDEX:
    case PIPE_CAP_VS_INSTANCEID:

src/gallium/drivers/nouveau/nvc0/nvc0_screen.c

@@ -243,7 +243,6 @@ nvc0_screen_get_param(struct pipe_screen *pscreen, enum pipe_cap param)
    case PIPE_CAP_INDEP_BLEND_FUNC:
    case PIPE_CAP_FS_COORD_ORIGIN_UPPER_LEFT:
    case PIPE_CAP_FS_COORD_PIXEL_CENTER_HALF_INTEGER:
-   case PIPE_CAP_POINT_COORD_ORIGIN_UPPER_LEFT:
    case PIPE_CAP_PRIMITIVE_RESTART:
    case PIPE_CAP_PRIMITIVE_RESTART_FIXED_INDEX:
    case PIPE_CAP_VS_INSTANCEID:

src/gallium/include/pipe/p_defines.h

@@ -755,7 +755,6 @@ enum pipe_cap
    PIPE_CAP_FS_COORD_ORIGIN_LOWER_LEFT,
    PIPE_CAP_FS_COORD_PIXEL_CENTER_HALF_INTEGER,
    PIPE_CAP_FS_COORD_PIXEL_CENTER_INTEGER,
-   PIPE_CAP_POINT_COORD_ORIGIN_UPPER_LEFT,
    PIPE_CAP_DEPTH_CLIP_DISABLE,
    PIPE_CAP_DEPTH_CLIP_DISABLE_SEPARATE,
    PIPE_CAP_DEPTH_CLAMP_ENABLE,

src/mesa/main/consts_exts.h

@@ -993,8 +993,5 @@ struct gl_constants
 
    /** Use hardware accelerated GL_SELECT */
    bool HardwareAcceleratedSelect;
-
-   /** Origin of point coordinates. True if upper left, false if lower left. */
-   bool PointCoordOriginUpperLeft;
 };
 #endif

src/mesa/program/prog_statevars.c

@@ -743,8 +743,7 @@ fetch_state(struct gl_context *ctx, const gl_state_index16 state[],
 
    case STATE_FB_PNTC_Y_TRANSFORM:
       {
-         bool flip_y = (ctx->Point.SpriteOrigin == GL_UPPER_LEFT) ^
-            (ctx->Const.PointCoordOriginUpperLeft) ^
+         bool flip_y = (ctx->Point.SpriteOrigin == GL_LOWER_LEFT) ^
             (ctx->DrawBuffer->FlipY);
 
          value[0] = flip_y ? -1.0F : 1.0F;

src/mesa/state_tracker/st_context.c

@@ -700,9 +700,6 @@ st_create_context_priv(struct gl_context *ctx, struct pipe_context *pipe,
    ctx->Point.MaxSize = MAX2(ctx->Const.MaxPointSize,
                              ctx->Const.MaxPointSizeAA);
 
-   ctx->Const.PointCoordOriginUpperLeft =
-      screen->get_param(screen, PIPE_CAP_POINT_COORD_ORIGIN_UPPER_LEFT);
-
    ctx->Const.NoClippingOnCopyTex = screen->get_param(screen,
                                                       PIPE_CAP_NO_CLIP_ON_COPY_TEX);