Attachment 31091 Details for Bug 17933 – Trust the alpha value (even for xRGB)

[patch] Trust the alpha value (even for xRGB)

0001-i915-Do-not-force-the-incoming-source-alpha-to-1.patch (text/plain), 2.32 KB, created by Chris Wilson on 2009-11-10 07:30:23 UTC

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Creator: Chris Wilson

Created: 2009-11-10 07:30:23 UTC

Size: 2.32 KB

patch

obsolete

>From 96602cd2be49c0c04895a29ad797f2ac7e3e2cbe Mon Sep 17 00:00:00 2001
>From: Chris Wilson <chris@chris-wilson.co.uk>
>Date: Tue, 10 Nov 2009 11:19:00 +0000
>Subject: [PATCH] i915: Do not force the incoming source alpha to 1.
>
>RENDER specifies that textures are extended with the clear colour in the
>EXTEND_NONE case. By forcing the border colour to contain 1, we were
>padding with black instead. This is a long standing bug that causes
>numerous failure in cairo and has been frequently bemoaned about in
>bugzilla.
>
>  https://bugs.freedesktop.org/show_bug.cgi?id=17933
>  x8r8g8b8 doesn't sample alpha=0 outside surface bounds
>
>However, one consequence of this is that we now must trust the incoming
>source alpha for x8r8g8b8 surfaces (and similar ignored alpha formats).
>We workaround this by ensuring that we fill the outgoing alpha channel
>with 1 for such targets, but we must also rely on the X server to fill
>the alpha channel on incoming RGB images.
>
>Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
>---
> src/i915_render.c |    9 +++------
> 1 files changed, 3 insertions(+), 6 deletions(-)
>
>diff --git a/src/i915_render.c b/src/i915_render.c
>index f64e031..8d8fde4 100644
>--- a/src/i915_render.c
>+++ b/src/i915_render.c
>@@ -446,7 +446,6 @@ static void i915_emit_composite_setup(ScrnInfoPtr scrn)
> {
> 	intel_screen_private *intel = intel_get_screen_private(scrn);
> 	int op = intel->i915_render_state.op;
>-	PicturePtr source_picture = intel->render_source_picture;
> 	PicturePtr mask_picture = intel->render_mask_picture;
> 	PicturePtr dest_picture = intel->render_dest_picture;
> 	PixmapPtr mask = intel->render_mask;
>@@ -600,10 +599,6 @@ static void i915_emit_composite_setup(ScrnInfoPtr scrn)
> 		    i915_fs_texldp(FS_R0, FS_S0, FS_T0);
> 		}
> 
>-		/* If the texture lacks an alpha channel, force the alpha to 1. */
>-		if (PICT_FORMAT_A(source_picture->format) == 0)
>-		    i915_fs_mov_masked(FS_R0, MASK_W, i915_fs_operand_one());
>-
> 		src_reg = FS_R0;
> 	    }
> 
>@@ -653,7 +648,9 @@ static void i915_emit_composite_setup(ScrnInfoPtr scrn)
> 		}
> 	    }
> 	    if (dst_format == COLR_BUF_8BIT)
>-		i915_fs_mov(FS_OC, i915_fs_operand(out_reg, W, W, W, W));
>+		    i915_fs_mov(FS_OC, i915_fs_operand(out_reg, W, W, W, W));
>+	    if (PICT_FORMAT_A(dest_picture->format) == 0)
>+		    i915_fs_mov_masked(FS_OC, MASK_W, i915_fs_operand_one());
> 
> 	    FS_END();
> 	}
>-- 
>1.6.5.2
>

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