i915tex: Triple buffering support, only effective with page flipping so far.

Pending flips are tracked per renderbuffer and the colour renderbuffer
attachments of window framebuffer objects are rotated on flips to avoid
stalling the pipeline for pending flips unnecessarily.

1 files changed, 35 insertions, 14 deletions

diff --git a/src/mesa/drivers/dri/i915tex/intel_fbo.c b/src/mesa/drivers/dri/i915tex/intel_fbo.c
index 104cf1d9bb..ad078451bf 100644
--- a/src/mesa/drivers/dri/i915tex/intel_fbo.c
+++ b/src/mesa/drivers/dri/i915tex/intel_fbo.c
@@ -71,22 +71,29 @@ intel_renderbuffer(struct gl_renderbuffer *rb)
 struct intel_renderbuffer *
 intel_get_renderbuffer(struct gl_framebuffer *fb, GLuint attIndex)
 {
-   if (fb->Name == 0) {
-      struct intel_framebuffer *intel_fb = (struct intel_framebuffer*)fb;
-
-      if (intel_fb->pf_current_page) {
-	 switch (attIndex) {
-	 case BUFFER_BACK_LEFT:
-	    attIndex = BUFFER_FRONT_LEFT;
-	    break;
-	 case BUFFER_FRONT_LEFT:
-	    attIndex = BUFFER_BACK_LEFT;
-	    break;
-	 }
-      }
+   return intel_renderbuffer(fb->Attachment[attIndex].Renderbuffer);
+}
+
+
+void
+intel_flip_renderbuffers(struct intel_framebuffer *intel_fb)
+{
+   int current_page = intel_fb->pf_current_page;
+   int next_page = (current_page + 1) % intel_fb->pf_num_pages;
+
+   if (intel_fb->Base.Attachment[BUFFER_FRONT_LEFT].Renderbuffer !=
+       &intel_fb->color_rb[current_page]->Base) {
+      _mesa_remove_renderbuffer(&intel_fb->Base, BUFFER_FRONT_LEFT);
+      _mesa_add_renderbuffer(&intel_fb->Base, BUFFER_FRONT_LEFT,
+			     &intel_fb->color_rb[current_page]->Base);
    }
 
-   return intel_renderbuffer(fb->Attachment[attIndex].Renderbuffer);
+   if (intel_fb->Base.Attachment[BUFFER_BACK_LEFT].Renderbuffer !=
+       &intel_fb->color_rb[next_page]->Base) {
+      _mesa_remove_renderbuffer(&intel_fb->Base, BUFFER_BACK_LEFT);
+      _mesa_add_renderbuffer(&intel_fb->Base, BUFFER_BACK_LEFT,
+			     &intel_fb->color_rb[next_page]->Base);
+   }
 }
 
 
@@ -288,10 +295,24 @@ static GLboolean
 intel_alloc_window_storage(GLcontext * ctx, struct gl_renderbuffer *rb,
                            GLenum internalFormat, GLuint width, GLuint height)
 {
+   struct intel_context *intel = intel_context(ctx);
+   struct intel_framebuffer *intel_fb;
+
    ASSERT(rb->Name == 0);
    rb->Width = width;
    rb->Height = height;
    rb->_ActualFormat = internalFormat;
+
+   if (intel && intel->driDrawable &&
+       (intel_fb = intel->driDrawable->driverPrivate) &&
+       intel_fb->pf_num_pages == 3 &&
+       rb == &intel_fb->color_rb[intel_fb->pf_current_page]->Base &&
+       (rb = &intel_fb->color_rb[(intel_fb->pf_current_page + 2) % 3]->Base)) {
+      rb->Width = width;
+      rb->Height = height;
+      rb->_ActualFormat = internalFormat;
+   }
+
    return GL_TRUE;
 }