xf86-video-intel: src/i830_render.c

[Eric Anholt]

 src/i830_render.c |   80 ++++++++++++++++++++++++++++++++----------------------
 1 file changed, 48 insertions(+), 32 deletions(-)

New commits:
commit c20d78a7bc512219fa36dfc9707fe65f66ab80f1
Author: Eric Anholt <eric at anholt.net>
Date:   Mon Mar 10 17:27:45 2008 -0700

    Add workarounds for 830/845's lack of a8/x8r8g8b8/x8b8g8r8 support.
    
    When we have unset channels (color for a8, or alpha for x8*), force them
    to the appropriate value in the texture combiner rather than relying on getting
    the desired results from teture mapping.  Performance is the same on 865, so
    multiple paths aren't necessary and we can use the less friendly texture
    formats everywhere.

diff --git a/src/i830_render.c b/src/i830_render.c
index ccfd670..1bb0103 100644
--- a/src/i830_render.c
+++ b/src/i830_render.c
@@ -143,11 +143,15 @@ static struct blendinfo i830_blend_op[] = {
     {0, 0, BLENDFACTOR_ONE, 		BLENDFACTOR_ONE},
 };
 
+/* The x8* formats could use MT_32BIT_X* on 855+, but since we implement
+ * workarounds for 830/845 anyway, we just rely on those whether the hardware
+ * could handle it for us or not.
+ */
 static struct formatinfo i830_tex_formats[] = {
     {PICT_a8r8g8b8, MT_32BIT_ARGB8888 },
-    {PICT_x8r8g8b8, MT_32BIT_XRGB8888 },
+    {PICT_x8r8g8b8, MT_32BIT_ARGB8888 },
     {PICT_a8b8g8r8, MT_32BIT_ABGR8888 },
-    {PICT_x8b8g8r8, MT_32BIT_XBGR8888 },
+    {PICT_x8b8g8r8, MT_32BIT_ABGR8888 },
     {PICT_r5g6b5,   MT_16BIT_RGB565   },
     {PICT_a1r5g5b5, MT_16BIT_ARGB1555 },
     {PICT_x1r5g5b5, MT_16BIT_ARGB1555 },
@@ -223,8 +227,6 @@ static uint32_t i830_get_blend_cntl(int op, PicturePtr pMask,
 
 static Bool i830_check_composite_texture(PicturePtr pPict, int unit)
 {
-    ScrnInfoPtr pScrn = xf86Screens[pPict->pDrawable->pScreen->myNum];
-    I830Ptr pI830 = I830PTR(pScrn);
     int w = pPict->pDrawable->width;
     int h = pPict->pDrawable->height;
     int i;
@@ -242,13 +244,6 @@ static Bool i830_check_composite_texture(PicturePtr pPict, int unit)
         I830FALLBACK("Unsupported picture format 0x%x\n",
 		     (int)pPict->format);
 
-    if (IS_I830(pI830) || IS_845G(pI830)) {
-	if (pPict->format == PICT_x8r8g8b8 || 
-		pPict->format == PICT_x8b8g8r8 || 
-		pPict->format == PICT_a8)
-	    I830FALLBACK("830/845G don't support a8, x8r8g8b8, x8b8g8r8\n");
-    }
-
     if (pPict->repeat && pPict->repeatType != RepeatNormal)
 	I830FALLBACK("unsupport repeat type\n");
 
@@ -461,40 +456,61 @@ i830_prepare_composite(int op, PicturePtr pSrcPicture,
 	OUT_RING(vf2); /* TEXCOORDFMT_2D */
 	OUT_RING(S3_CULLMODE_NONE | S3_VERTEXHAS_XY);
 
-	/* We use two pipes for color and alpha, and do (src In mask)
-	   in one stage. Arg1 is from src pict, and arg2 is from mask pict.
-	   Be sure to force 1.0 when src or mask pict has no alpha channel.
+	/* If component alpha is active in the mask and the blend operation
+	 * uses the source alpha, then we know we don't need the source
+	 * value (otherwise we would have hit a fallback earlier), so we
+	 * provide the source alpha (src.A * mask.X) as output color.
+	 * Conversely, if CA is set and we don't need the source alpha, then
+	 * we produce the source value (src.X * mask.X) and the source alpha
+	 * is unused..  Otherwise, we provide the non-CA source value
+	 * (src.X * mask.A).
+	 *
+	 * The PICT_FORMAT_RGB(pict) == 0 fixups are not needed on 855+'s a8
+	 * pictures, but we need to implement it for 830/845 and there's no
+	 * harm done in leaving it in.
 	 */
 	cblend = TB0C_LAST_STAGE | TB0C_RESULT_SCALE_1X | TB0C_OP_MODULE |
 		 TB0C_OUTPUT_WRITE_CURRENT;
 	ablend = TB0A_RESULT_SCALE_1X | TB0A_OP_MODULE |
 		 TB0A_OUTPUT_WRITE_CURRENT;
 
-	if (PICT_FORMAT_A(pSrcPicture->format) != 0) {
-	    ablend |= TB0A_ARG1_SEL_TEXEL0;
-	    cblend |= TB0C_ARG1_SEL_TEXEL0;
-	} else {
-	    ablend |= TB0A_ARG1_SEL_ONE;
-	    if (pMask && pMaskPicture->componentAlpha 
-		    && PICT_FORMAT_RGB(pMaskPicture->format)
-		    && i830_blend_op[op].src_alpha)
+	/* Get the source picture's channels into TBx_ARG1 */
+	if (pMaskPicture != NULL &&
+	    pMaskPicture->componentAlpha &&
+	    PICT_FORMAT_RGB(pMaskPicture->format) &&
+	    i830_blend_op[op].src_alpha)
+	{
+	    /* Producing source alpha value, so the first set of channels
+	     * is src.A instead of src.X
+	     */
+	    if (PICT_FORMAT_A(pSrcPicture->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;
-	    else
+	    }
+	} else {
+	    if (PICT_FORMAT_A(pSrcPicture->format) != 0) {
+		ablend |= TB0A_ARG1_SEL_TEXEL0;
+	    } else {
+		ablend |= TB0A_ARG1_SEL_ONE;
+	    }
+	    if (PICT_FORMAT_RGB(pSrcPicture->format) != 0)
 		cblend |= TB0C_ARG1_SEL_TEXEL0;
+	    else
+		cblend |= TB0C_ARG1_SEL_ONE | TB0C_ARG1_INVERT; /* 0.0 */
 	}
 
 	if (pMask) {
-	    if (pMaskPicture->componentAlpha && 
-		    PICT_FORMAT_RGB(pMaskPicture->format)) {
-		if (i830_blend_op[op].src_alpha)
-		    cblend |= (TB0C_ARG2_SEL_TEXEL1 | 
-			    TB0C_ARG1_REPLICATE_ALPHA);
-		else 
-		    cblend |= TB0C_ARG2_SEL_TEXEL1;
+	    if (pMaskPicture->componentAlpha &&
+		PICT_FORMAT_RGB(pMaskPicture->format))
+	    {
+		cblend |= TB0C_ARG2_SEL_TEXEL1;
 	    } else {
 		if (PICT_FORMAT_A(pMaskPicture->format) != 0)
-		    cblend |= (TB0C_ARG2_SEL_TEXEL1 | 
-			    TB0C_ARG2_REPLICATE_ALPHA);
+		    cblend |= TB0C_ARG2_SEL_TEXEL1 |
+			TB0C_ARG2_REPLICATE_ALPHA;
 		else
 		    cblend |= TB0C_ARG2_SEL_ONE;
 	    }