Fill alpha on xrgb images.

Do not try to fixup the alpha in the ff/shaders as this has the
side-effect of overriding the alpha value of the border color, causing
images to be padded with black rather than transparent. This can
generate large and obnoxious visual artefacts.

Fixes:

  Bug 17933 - x8r8g8b8 doesn't sample alpha=0 outside surface bounds
  http://bugs.freedesktop.org/show_bug.cgi?id=17933

and many related cairo test suite failures.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>

4 files changed, 88 insertions, 117 deletions

diff --git a/src/i830_render.c b/src/i830_render.c
index 0d6a8034..71296d29 100644
--- a/src/i830_render.c
+++ b/src/i830_render.c
@@ -491,43 +491,23 @@ i830_prepare_composite(int op, PicturePtr source_picture,
 			 * is a8, in which case src.G is what's written, and the other
 			 * channels are ignored.
 			 */
-			if (PICT_FORMAT_A(source_picture->format) != 0) {
-				ablend |= TB0A_ARG1_SEL_TEXEL0;
-				cblend |=
-				    TB0C_ARG1_SEL_TEXEL0 |
-				    TB0C_ARG1_REPLICATE_ALPHA;
-			} else {
-				ablend |= TB0A_ARG1_SEL_ONE;
-				cblend |= TB0C_ARG1_SEL_ONE;
-			}
+			ablend |= TB0A_ARG1_SEL_TEXEL0;
+			cblend |= TB0C_ARG1_SEL_TEXEL0 | TB0C_ARG1_REPLICATE_ALPHA;
 		} else {
-			if (PICT_FORMAT_A(source_picture->format) != 0) {
-				ablend |= TB0A_ARG1_SEL_TEXEL0;
-			} else {
-				ablend |= TB0A_ARG1_SEL_ONE;
-			}
 			if (PICT_FORMAT_RGB(source_picture->format) != 0)
 				cblend |= TB0C_ARG1_SEL_TEXEL0;
 			else
 				cblend |= TB0C_ARG1_SEL_ONE | TB0C_ARG1_INVERT;	/* 0.0 */
+			ablend |= TB0A_ARG1_SEL_TEXEL0;
 		}
 
 		if (mask) {
-			if (dest_picture->format != PICT_a8 &&
-			    (mask_picture->componentAlpha &&
-			     PICT_FORMAT_RGB(mask_picture->format))) {
-				cblend |= TB0C_ARG2_SEL_TEXEL1;
-			} else {
-				if (PICT_FORMAT_A(mask_picture->format) != 0)
-					cblend |= TB0C_ARG2_SEL_TEXEL1 |
-					    TB0C_ARG2_REPLICATE_ALPHA;
-				else
-					cblend |= TB0C_ARG2_SEL_ONE;
-			}
-			if (PICT_FORMAT_A(mask_picture->format) != 0)
-				ablend |= TB0A_ARG2_SEL_TEXEL1;
-			else
-				ablend |= TB0A_ARG2_SEL_ONE;
+			cblend |= TB0C_ARG2_SEL_TEXEL1;
+			if (dest_picture->format == PICT_a8 ||
+			    ! mask_picture->componentAlpha ||
+			    ! PICT_FORMAT_RGB(mask_picture->format))
+				cblend |= TB0C_ARG2_REPLICATE_ALPHA;
+			ablend |= TB0A_ARG2_SEL_TEXEL1;
 		} else {
 			cblend |= TB0C_ARG2_SEL_ONE;
 			ablend |= TB0A_ARG2_SEL_ONE;
diff --git a/src/i830_uxa.c b/src/i830_uxa.c
index 99043118..fec53782 100644
--- a/src/i830_uxa.c
+++ b/src/i830_uxa.c
@@ -237,6 +237,8 @@ i830_uxa_prepare_solid(PixmapPtr pixmap, int alu, Pixel planemask, Pixel fg)
 	case 32:
 		/* RGB8888 */
 		intel->BR[13] |= ((1 << 24) | (1 << 25));
+		if (pixmap->drawable.depth == 24)
+		    fg |= 0xff000000;
 		break;
 	}
 	intel->BR[16] = fg;
@@ -710,6 +712,33 @@ static Bool i830_uxa_put_image(PixmapPtr pixmap,
 	GCPtr gc;
 	Bool ret;
 
+	if (pixmap->drawable.depth == 24) {
+	    /* fill alpha channel */
+	    pixman_image_t *src_image, *dst_image;
+
+	    src_image = pixman_image_create_bits (PIXMAN_x8r8g8b8,
+						  w, h,
+						  (uint32_t *) src, src_pitch);
+
+	    dst_image = pixman_image_create_bits (PIXMAN_a8r8g8b8,
+						  w, h,
+						  (uint32_t *) src, src_pitch);
+
+	    if (src_image && dst_image)
+		pixman_image_composite (PictOpSrc,
+					src_image, NULL, dst_image,
+					0, 0,
+					0, 0,
+					0, 0,
+					w, h);
+
+	    if (src_image)
+		pixman_image_unref (src_image);
+
+	    if (dst_image)
+		pixman_image_unref (dst_image);
+	}
+
 	if (x == 0 && y == 0 &&
 	    w == pixmap->drawable.width &&
 	    h == pixmap->drawable.height)
diff --git a/src/i915_render.c b/src/i915_render.c
index 37af72b9..c4aa9a44 100644
--- a/src/i915_render.c
+++ b/src/i915_render.c
@@ -385,8 +385,9 @@ i915_prepare_composite(int op, PicturePtr source_picture,
 					    source_picture->format,
 					    PICT_a8r8g8b8,
 					    &intel->render_source_solid))
-		return FALSE;
-	} else if (!intel_check_pitch_3d(source))
+		intel->render_source_is_solid = FALSE;
+	}
+	if (!intel->render_source_is_solid && !intel_check_pitch_3d(source))
 		return FALSE;
 
 
@@ -402,8 +403,9 @@ i915_prepare_composite(int op, PicturePtr source_picture,
 						mask_picture->format,
 						PICT_a8r8g8b8,
 						&intel->render_mask_solid))
-		    return FALSE;
-	    } else if (!intel_check_pitch_3d(mask))
+		    intel->render_mask_is_solid = FALSE;
+	    }
+	    if (!intel->render_mask_is_solid && !intel_check_pitch_3d(mask))
 		    return FALSE;
 	}
 
@@ -475,7 +477,6 @@ 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;
@@ -589,7 +590,6 @@ static void i915_emit_composite_setup(ScrnInfoPtr scrn)
 		OUT_BATCH(0x00000000);
 	}
 
-	OUT_BATCH(MI_NOOP);
 	ADVANCE_BATCH();
 
 	{
@@ -629,10 +629,6 @@ 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;
 	    }
 
@@ -647,11 +643,6 @@ static void i915_emit_composite_setup(ScrnInfoPtr scrn)
 		    } else {
 			i915_fs_texldp(FS_R1, FS_S0 + t, FS_T0 + t);
 		    }
-		    /* If the texture lacks an alpha channel, force the alpha to 1.
-		     */
-		    if (PICT_FORMAT_A(mask_picture->format) == 0)
-			i915_fs_mov_masked(FS_R1, MASK_W,
-					   i915_fs_operand_one());
 
 		    mask_reg = FS_R1;
 		}
diff --git a/uxa/uxa-render.c b/uxa/uxa-render.c
index e70a8450..ca46a2a9 100644
--- a/uxa/uxa-render.c
+++ b/uxa/uxa-render.c
@@ -262,13 +262,15 @@ uxa_get_color_for_pixmap (PixmapPtr	 pixmap,
 
 	*pixel = uxa_get_pixmap_first_pixel(pixmap);
 
-	if (!uxa_get_rgba_from_pixel(*pixel, &red, &green, &blue, &alpha,
-				     src_format))
+	if (src_format != dst_format) {
+	    if (!uxa_get_rgba_from_pixel(*pixel, &red, &green, &blue, &alpha,
+					 src_format))
 		return FALSE;
 
-	if (!uxa_get_pixel_from_rgba(pixel, red, green, blue, alpha,
-				     dst_format))
+	    if (!uxa_get_pixel_from_rgba(pixel, red, green, blue, alpha,
+					 dst_format))
 		return FALSE;
+	}
 
 	return TRUE;
 }
@@ -364,6 +366,10 @@ uxa_picture_for_pixman_format(ScreenPtr pScreen,
 	if (format == PIXMAN_a1)
 		format = PIXMAN_a8;
 
+	/* fill alpha if unset */
+	if (PIXMAN_FORMAT_A(format) == 0)
+	    format = PIXMAN_a8r8g8b8;
+
 	pPixmap = (*pScreen->CreatePixmap)(pScreen, width, height,
 					   PIXMAN_FORMAT_DEPTH(format),
 					   UXA_CREATE_PIXMAP_FOR_MAP);
@@ -384,64 +390,6 @@ uxa_picture_for_pixman_format(ScreenPtr pScreen,
 	return pPicture;
 }
 
-/* In order to avoid fallbacks when using an a1 source/mask,
- * for example with non-antialiased trapezoids, we need to
- * expand the bitmap into an a8 Picture. We do so by using the generic
- * composition routines, which while may not be perfect is far faster
- * than causing a fallback.
- */
-static PicturePtr
-uxa_picture_from_a1_pixman_image(ScreenPtr pScreen, pixman_image_t * image)
-{
-	PicturePtr pPicture;
-	PicturePtr pSrc;
-	PixmapPtr pPixmap;
-	int width, height;
-	int error;
-
-	width = pixman_image_get_width(image);
-	height = pixman_image_get_height(image);
-
-	pPicture = uxa_picture_for_pixman_format (pScreen, PIXMAN_a1,
-						  width, height);
-	if (!pPicture)
-		return 0;
-
-	pPixmap = GetScratchPixmapHeader(pScreen, width, height, 1, 1,
-					 pixman_image_get_stride(image),
-					 pixman_image_get_data(image));
-	if (!pPixmap) {
-		FreePicture(pPicture, 0);
-		return 0;
-	}
-
-	pSrc = CreatePicture(0, &pPixmap->drawable,
-			     PictureMatchFormat(pScreen, 1, PICT_a1),
-			     0, 0, serverClient, &error);
-	if (!pSrc) {
-		FreeScratchPixmapHeader(pPixmap);
-		FreePicture(pPicture, 0);
-		return 0;
-	}
-
-	ValidatePicture(pSrc);
-
-	/* force the fallback path */
-	if (uxa_prepare_access(pPicture->pDrawable, UXA_ACCESS_RW)) {
-		fbComposite(PictOpSrc, pSrc, NULL, pPicture,
-			    0, 0, 0, 0, 0, 0, width, height);
-		uxa_finish_access(pPicture->pDrawable);
-	} else {
-		FreePicture(pPicture, 0);
-		pPicture = 0;
-	}
-
-	FreePicture(pSrc, 0);
-	FreeScratchPixmapHeader(pPixmap);
-
-	return pPicture;
-}
-
 static PicturePtr
 uxa_picture_from_pixman_image(ScreenPtr pScreen,
 			      pixman_image_t * image,
@@ -449,12 +397,8 @@ uxa_picture_from_pixman_image(ScreenPtr pScreen,
 {
 	PicturePtr pPicture;
 	PixmapPtr pPixmap;
-	GCPtr pGC;
 	int width, height;
 
-	if (format == PICT_a1)
-		return uxa_picture_from_a1_pixman_image(pScreen, image);
-
 	width = pixman_image_get_width(image);
 	height = pixman_image_get_height(image);
 
@@ -473,18 +417,45 @@ uxa_picture_from_pixman_image(ScreenPtr pScreen,
 		return 0;
 	}
 
-	pGC = GetScratchGC(PIXMAN_FORMAT_DEPTH(format), pScreen);
-	if (!pGC) {
+	if (((pPicture->pDrawable->depth << 24) | pPicture->format) == format) {
+	    GCPtr pGC;
+
+	    pGC = GetScratchGC(PIXMAN_FORMAT_DEPTH(format), pScreen);
+	    if (!pGC) {
 		FreeScratchPixmapHeader(pPixmap);
 		FreePicture(pPicture, 0);
 		return 0;
-	}
-	ValidateGC(pPicture->pDrawable, pGC);
+	    }
+	    ValidateGC(pPicture->pDrawable, pGC);
 
-	(*pGC->ops->CopyArea) (&pPixmap->drawable, pPicture->pDrawable,
-			       pGC, 0, 0, width, height, 0, 0);
+	    (*pGC->ops->CopyArea) (&pPixmap->drawable, pPicture->pDrawable,
+				   pGC, 0, 0, width, height, 0, 0);
 
-	FreeScratchGC(pGC);
+	    FreeScratchGC(pGC);
+	} else {
+	    PicturePtr pSrc;
+	    int error;
+
+	    pSrc = CreatePicture(0, &pPixmap->drawable,
+				 PictureMatchFormat(pScreen,
+						    PIXMAN_FORMAT_DEPTH(format),
+						    format),
+				 0, 0, serverClient, &error);
+	    if (!pSrc) {
+		FreeScratchPixmapHeader(pPixmap);
+		FreePicture(pPicture, 0);
+		return 0;
+	    }
+	    ValidatePicture(pSrc);
+
+	    if (uxa_prepare_access(pPicture->pDrawable, UXA_ACCESS_RW)) {
+		fbComposite(PictOpSrc, pSrc, NULL, pPicture,
+			    0, 0, 0, 0, 0, 0, width, height);
+		uxa_finish_access(pPicture->pDrawable);
+	    }
+
+	    FreePicture(pSrc, 0);
+	}
 	FreeScratchPixmapHeader(pPixmap);
 
 	return pPicture;