fix [2071412] work around mdp 32-bits fade limitation
in the case where we fade a 32-bits surface (ie: GL_MODULATE w/ a,a,a,a + blending),
we first make a copy of the background into a RGB buffer, then we blend the 32-bits
surface as usual (without the alpha component), and finally blend the copy of
the background on top with 1-a. This uses a lot of bandwidth, but no CPU time.
diff --git a/opengl/libagl/copybit.cpp b/opengl/libagl/copybit.cpp
index 0c3d0ee..4b9e59b 100644
--- a/opengl/libagl/copybit.cpp
+++ b/opengl/libagl/copybit.cpp
@@ -154,6 +154,8 @@
int transform,
ogles_context_t* c)
{
+ status_t err = NO_ERROR;
+
// We assume checkContext has already been called and has already
// returned true.
@@ -200,6 +202,7 @@
const uint32_t enables = c->rasterizer.state.enables;
int planeAlpha = 255;
+ bool alphaPlaneWorkaround = false;
static const int tmu = 0;
texture_t& tev(c->rasterizer.state.texture[tmu]);
int32_t opFormat = textureObject->surface.format;
@@ -259,9 +262,10 @@
if (c->currentColorClamped.r == c->currentColorClamped.a &&
c->currentColorClamped.g == c->currentColorClamped.a &&
c->currentColorClamped.b == c->currentColorClamped.a) {
- // TODO: Need to emulate: RGBA source, color={a,a,a,a} / premult
- // and RGBA source, color={1,1,1,a} / regular-blending
- // (both are equivalent)
+ // TODO: RGBA source, color={1,1,1,a} / regular-blending
+ // is equivalent
+ alphaPlaneWorkaround = true;
+ break;
}
}
LOGD_IF(DEBUG_COPYBIT, "GGL_MODULATE");
@@ -331,13 +335,13 @@
tmp_w, tmp_h, src.format,
GraphicBuffer::USAGE_HW_2D);
- status_t err = tempBitmap->initCheck();
+ err = tempBitmap->initCheck();
if (err == NO_ERROR) {
copybit_image_t tmp_dst;
copybit_rect_t tmp_rect;
tmp_dst.w = tmp_w;
tmp_dst.h = tmp_h;
- tmp_dst.format = src.format;
+ tmp_dst.format = tempBitmap->format;
tmp_dst.handle = (native_handle_t*)tempBitmap->getNativeBuffer()->handle;
tmp_rect.l = 0;
tmp_rect.t = 0;
@@ -359,13 +363,66 @@
textureToCopyBitImage(&cbSurface, cbSurface.format, target_hnd, &dst);
copybit_rect_t drect = {x, y, x+w, y+h};
- copybit->set_parameter(copybit, COPYBIT_TRANSFORM, transform);
- copybit->set_parameter(copybit, COPYBIT_PLANE_ALPHA, planeAlpha);
- copybit->set_parameter(copybit, COPYBIT_DITHER,
- (enables & GGL_ENABLE_DITHER) ? COPYBIT_ENABLE : COPYBIT_DISABLE);
- clipRectRegion it(c);
- status_t err = copybit->stretch(copybit, &dst, &src, &drect, &srect, &it);
+ /* and now the alpha-plane hack. This handles the "Fade" case of a
+ * texture with an alpha channel.
+ */
+ if (alphaPlaneWorkaround) {
+ sp<GraphicBuffer> tempCb = new GraphicBuffer(
+ w, h, COPYBIT_FORMAT_RGB_565,
+ GraphicBuffer::USAGE_HW_2D);
+
+ err = tempCb->initCheck();
+
+ copybit_image_t tmpCbImg;
+ copybit_rect_t tmpCbRect;
+ tmpCbImg.w = w;
+ tmpCbImg.h = h;
+ tmpCbImg.format = tempCb->format;
+ tmpCbImg.handle = (native_handle_t*)tempCb->getNativeBuffer()->handle;
+ tmpCbRect.l = 0;
+ tmpCbRect.t = 0;
+ tmpCbRect.r = w;
+ tmpCbRect.b = h;
+
+ if (!err) {
+ // first make a copy of the destination buffer
+ region_iterator tmp_it(Region(Rect(w, h)));
+ copybit->set_parameter(copybit, COPYBIT_TRANSFORM, 0);
+ copybit->set_parameter(copybit, COPYBIT_PLANE_ALPHA, 0xFF);
+ copybit->set_parameter(copybit, COPYBIT_DITHER, COPYBIT_DISABLE);
+ err = copybit->stretch(copybit,
+ &tmpCbImg, &dst, &tmpCbRect, &drect, &tmp_it);
+ }
+ if (!err) {
+ // then proceed as usual, but without the alpha plane
+ copybit->set_parameter(copybit, COPYBIT_TRANSFORM, transform);
+ copybit->set_parameter(copybit, COPYBIT_PLANE_ALPHA, 0xFF);
+ copybit->set_parameter(copybit, COPYBIT_DITHER,
+ (enables & GGL_ENABLE_DITHER) ?
+ COPYBIT_ENABLE : COPYBIT_DISABLE);
+ clipRectRegion it(c);
+ err = copybit->stretch(copybit, &dst, &src, &drect, &srect, &it);
+ }
+ if (!err) {
+ // finally copy back the destination on top with 1-alphaplane
+ int invPlaneAlpha = 0xFF - fixedToByte(c->currentColorClamped.a);
+ clipRectRegion it(c);
+ copybit->set_parameter(copybit, COPYBIT_TRANSFORM, 0);
+ copybit->set_parameter(copybit, COPYBIT_PLANE_ALPHA, invPlaneAlpha);
+ copybit->set_parameter(copybit, COPYBIT_DITHER, COPYBIT_ENABLE);
+ err = copybit->stretch(copybit,
+ &dst, &tmpCbImg, &drect, &tmpCbRect, &it);
+ }
+ } else {
+ copybit->set_parameter(copybit, COPYBIT_TRANSFORM, transform);
+ copybit->set_parameter(copybit, COPYBIT_PLANE_ALPHA, planeAlpha);
+ copybit->set_parameter(copybit, COPYBIT_DITHER,
+ (enables & GGL_ENABLE_DITHER) ?
+ COPYBIT_ENABLE : COPYBIT_DISABLE);
+ clipRectRegion it(c);
+ err = copybit->stretch(copybit, &dst, &src, &drect, &srect, &it);
+ }
if (err != NO_ERROR) {
c->textures.tmu[0].texture->try_copybit = false;
}
