swrast* (gallium, classic): add MESA_copy_sub_buffer support (v3)

This patches add MESA_copy_sub_buffer support to the dri sw loader and
then to gallium state tracker, llvmpipe, softpipe and other bits.

It reuses the dri1 driver extension interface, and it updates the swrast
loader interface for a new putimage which can take a stride.

I've tested this with gnome-shell with a cogl hacked to reenable sub copies
for llvmpipe and the one piglit test.

I could probably split this patch up as well.

v2: pass a pipe_box, to reduce the entrypoints, as per Jose's review,
add to p_screen doc comments.

v3: finish off winsys interfaces, add swrast classic support as well.

Reviewed-by: Jose Fonseca <[email protected]>
Signed-off-by: Dave Airlie <[email protected]>

swrast: add support for copy_sub_buffer

3 files changed, 54 insertions, 1 deletions

diff --git a/src/mesa/drivers/dri/common/dri_util.c b/src/mesa/drivers/dri/common/dri_util.c
index 0bce77ea9c7..fd2eca715c3 100644
--- a/src/mesa/drivers/dri/common/dri_util.c
+++ b/src/mesa/drivers/dri/common/dri_util.c
@@ -873,3 +873,18 @@ const __DRIimageDriverExtension driImageDriverExtension = {
     .getAPIMask                 = driGetAPIMask,
     .createContextAttribs       = driCreateContextAttribs,
 };
+
+/* swrast copy sub buffer entrypoint. */
+static void driCopySubBuffer(__DRIdrawable *pdp, int x, int y,
+                             int w, int h)
+{
+    assert(pdp->driScreenPriv->swrast_loader);
+
+    pdp->driScreenPriv->driver->CopySubBuffer(pdp, x, y, w, h);
+}
+
+/* for swrast only */
+const __DRIcopySubBufferExtension driCopySubBufferExtension = {
+   { __DRI_COPY_SUB_BUFFER, 1 },
+   .copySubBuffer = driCopySubBuffer,
+};
diff --git a/src/mesa/drivers/dri/common/dri_util.h b/src/mesa/drivers/dri/common/dri_util.h
index 79a8564ad51..4cfa75dd3e4 100644
--- a/src/mesa/drivers/dri/common/dri_util.h
+++ b/src/mesa/drivers/dri/common/dri_util.h
@@ -66,7 +66,7 @@ extern const __DRIcoreExtension driCoreExtension;
 extern const __DRIswrastExtension driSWRastExtension;
 extern const __DRIdri2Extension driDRI2Extension;
 extern const __DRI2configQueryExtension dri2ConfigQueryExtension;
-
+extern const __DRIcopySubBufferExtension driCopySubBufferExtension;
 /**
  * Driver callback functions.
  *
@@ -115,6 +115,9 @@ struct __DriverAPIRec {
                                     int width, int height);
 
     void (*ReleaseBuffer) (__DRIscreen *screenPrivate, __DRIbuffer *buffer);
+
+    void (*CopySubBuffer)(__DRIdrawable *driDrawPriv, int x, int y,
+                          int w, int h);
 };
 
 extern const struct __DriverAPIRec driDriverAPI;
diff --git a/src/mesa/drivers/dri/swrast/swrast.c b/src/mesa/drivers/dri/swrast/swrast.c
index 0e1c530b39d..7eed5a418cb 100644
--- a/src/mesa/drivers/dri/swrast/swrast.c
+++ b/src/mesa/drivers/dri/swrast/swrast.c
@@ -820,6 +820,39 @@ dri_unbind_context(__DRIcontext * cPriv)
     return GL_TRUE;
 }
 
+static void
+dri_copy_sub_buffer(__DRIdrawable *dPriv, int x, int y,
+                    int w, int h)
+{
+    __DRIscreen *sPriv = dPriv->driScreenPriv;
+    void *data;
+    int iy;
+    struct dri_drawable *drawable = dri_drawable(dPriv);
+    struct gl_framebuffer *fb;
+    struct dri_swrast_renderbuffer *frontrb, *backrb;
+
+    TRACE;
+
+    fb = &drawable->Base;
+
+    frontrb =
+	dri_swrast_renderbuffer(fb->Attachment[BUFFER_FRONT_LEFT].Renderbuffer);
+    backrb =
+	dri_swrast_renderbuffer(fb->Attachment[BUFFER_BACK_LEFT].Renderbuffer);
+
+    /* check for signle-buffered */
+    if (backrb == NULL)
+       return;
+
+    iy = frontrb->Base.Base.Height - y - h;
+    data = (char *)backrb->Base.Buffer + (iy * backrb->pitch) + (x * ((backrb->bpp + 7) / 8));
+    sPriv->swrast_loader->putImage2(dPriv, __DRI_SWRAST_IMAGE_OP_SWAP,
+                                    x, iy, w, h,
+                                    frontrb->pitch,
+                                    data,
+                                    dPriv->loaderPrivate);
+}
+
 
 static const struct __DriverAPIRec swrast_driver_api = {
     .InitScreen = dri_init_screen,
@@ -831,6 +864,7 @@ static const struct __DriverAPIRec swrast_driver_api = {
     .SwapBuffers = dri_swap_buffers,
     .MakeCurrent = dri_make_current,
     .UnbindContext = dri_unbind_context,
+    .CopySubBuffer = dri_copy_sub_buffer,
 };
 
 static const struct __DRIDriverVtableExtensionRec swrast_vtable = {
@@ -841,6 +875,7 @@ static const struct __DRIDriverVtableExtensionRec swrast_vtable = {
 static const __DRIextension *swrast_driver_extensions[] = {
     &driCoreExtension.base,
     &driSWRastExtension.base,
+    &driCopySubBufferExtension.base,
     &swrast_vtable.base,
     NULL
 };