[Mesa-dev] [PATCH 4/7] helper-conveniance functions for drivers to implement ARB_framebuffer_no_attachment

kevin.rogovin at intel.com kevin.rogovin at intel.com
Thu Apr 23 23:59:07 PDT 2015


From: Kevin Rogovin <kevin.rogovin at intel.com>

To assist drivers to implement ARB_framebuffer_no_attachment, provide
a set of convenience functions that check for gl_framebuffer::_HasAttachments
that return the geometry of the gl_framebuffer.

---
 src/mesa/main/framebuffer.c | 49 ++++++++++++++++++++++++++++++---------------
 src/mesa/main/framebuffer.h | 29 +++++++++++++++++++++++++++
 src/mesa/main/mtypes.h      | 21 ++++++++++---------
 3 files changed, 74 insertions(+), 25 deletions(-)

diff --git a/src/mesa/main/framebuffer.c b/src/mesa/main/framebuffer.c
index 4e4d896..7d8921b 100644
--- a/src/mesa/main/framebuffer.c
+++ b/src/mesa/main/framebuffer.c
@@ -357,30 +357,20 @@ update_framebuffer_size(struct gl_context *ctx, struct gl_framebuffer *fb)
 }
 
 
+
 /**
- * Calculate the inclusive bounding box for the scissor of a specific viewport
+ * Given a bounding box, intersect the bounding box with the scirros of
+ * a specified vieport.
  *
  * \param ctx     GL context.
- * \param buffer  Framebuffer to be checked against
  * \param idx     Index of the desired viewport
  * \param bbox    Bounding box for the scissored viewport.  Stored as xmin,
  *                xmax, ymin, ymax.
- *
- * \warning This function assumes that the framebuffer dimensions are up to
- * date (e.g., update_framebuffer_size has been recently called on \c buffer).
- *
- * \sa _mesa_clip_to_region
  */
-void
-_mesa_scissor_bounding_box(const struct gl_context *ctx,
-                           const struct gl_framebuffer *buffer,
-                           unsigned idx, int *bbox)
+extern void
+_mesa_intersect_scissor_bounding_box(const struct gl_context *ctx,
+                                     unsigned idx, int *bbox)
 {
-   bbox[0] = 0;
-   bbox[2] = 0;
-   bbox[1] = buffer->Width;
-   bbox[3] = buffer->Height;
-
    if (ctx->Scissor.EnableFlags & (1u << idx)) {
       if (ctx->Scissor.ScissorArray[idx].X > bbox[0]) {
          bbox[0] = ctx->Scissor.ScissorArray[idx].X;
@@ -402,6 +392,33 @@ _mesa_scissor_bounding_box(const struct gl_context *ctx,
          bbox[2] = bbox[3];
       }
    }
+}
+
+/**
+ * Calculate the inclusive bounding box for the scissor of a specific viewport
+ *
+ * \param ctx     GL context.
+ * \param buffer  Framebuffer to be checked against
+ * \param idx     Index of the desired viewport
+ * \param bbox    Bounding box for the scissored viewport.  Stored as xmin,
+ *                xmax, ymin, ymax.
+ *
+ * \warning This function assumes that the framebuffer dimensions are up to
+ * date (e.g., update_framebuffer_size has been recently called on \c buffer).
+ *
+ * \sa _mesa_clip_to_region
+ */
+void
+_mesa_scissor_bounding_box(const struct gl_context *ctx,
+                           const struct gl_framebuffer *buffer,
+                           unsigned idx, int *bbox)
+{
+   bbox[0] = 0;
+   bbox[2] = 0;
+   bbox[1] = buffer->Width;
+   bbox[3] = buffer->Height;
+
+   _mesa_intersect_scissor_bounding_box(ctx, idx, bbox);
 
    assert(bbox[0] <= bbox[1]);
    assert(bbox[2] <= bbox[3]);
diff --git a/src/mesa/main/framebuffer.h b/src/mesa/main/framebuffer.h
index a427421..8b84d26 100644
--- a/src/mesa/main/framebuffer.h
+++ b/src/mesa/main/framebuffer.h
@@ -76,6 +76,35 @@ _mesa_scissor_bounding_box(const struct gl_context *ctx,
                            const struct gl_framebuffer *buffer,
                            unsigned idx, int *bbox);
 
+extern void
+_mesa_intersect_scissor_bounding_box(const struct gl_context *ctx,
+                                     unsigned idx, int *bbox);
+
+static inline  GLuint
+_mesa_geometric_width(const struct gl_framebuffer *buffer)
+{
+   return buffer->_HasAttachments ? buffer->Width : buffer->DefaultGeometry.Width;
+}
+
+
+static inline  GLuint
+_mesa_geometric_height(const struct gl_framebuffer *buffer)
+{
+   return buffer->_HasAttachments ? buffer->Height : buffer->DefaultGeometry.Height;
+}
+
+static inline  GLuint
+_mesa_geometric_samples(const struct gl_framebuffer *buffer)
+{
+   return buffer->_HasAttachments ? buffer->Visual.samples : buffer->DefaultGeometry.NumSamples;
+}
+
+static inline  GLuint
+_mesa_geometric_layers(const struct gl_framebuffer *buffer)
+{
+   return buffer->_HasAttachments ? buffer->MaxNumLayers : buffer->DefaultGeometry.Layers;
+}
+
 extern void 
 _mesa_update_draw_buffer_bounds(struct gl_context *ctx);
 
diff --git a/src/mesa/main/mtypes.h b/src/mesa/main/mtypes.h
index 38a3817..ac7cdb6 100644
--- a/src/mesa/main/mtypes.h
+++ b/src/mesa/main/mtypes.h
@@ -3134,13 +3134,13 @@ struct gl_framebuffer
    struct gl_config Visual;
 
    /**
-    * size of frame buffer in pixels, 
-    * no attachments has these values as 0 
+    * size of frame buffer in pixels,
+    * no attachments has these values as 0
     */
-   GLuint Width, Height;	
+   GLuint Width, Height;
 
    /**
-    * In the case that the framebuffer has no attachment (i.e. 
+    * In the case that the framebuffer has no attachment (i.e.
     * GL_ARB_framebuffer_no_attachments) then the geometry of
     * the framebuffer is specified by the default values.
     */
@@ -3154,8 +3154,8 @@ struct gl_framebuffer
     * (inclusive for _Xmin and _Ymin while exclusive for _Xmax and _Ymax)
     */
    /*@{*/
-   GLint _Xmin, _Xmax;  
-   GLint _Ymin, _Ymax;  
+   GLint _Xmin, _Xmax;
+   GLint _Ymin, _Ymax;
    /*@}*/
 
    /** \name  Derived Z buffer stuff */
@@ -3172,13 +3172,16 @@ struct gl_framebuffer
     *  - one of Attachment has gl_renderbuffer_attachment::Type != GL_NONE
     *  - _Status is GL_FRAMEBUFFER_COMPLETE_EXT
     * NOTE: the values for Width and Height are set to 0 in the
-    * case of no attachments, a backend driver supporting 
-    * GL_ARB_framebuffer_no_attachments must check for 
+    * case of no attachments, a backend driver supporting
+    * GL_ARB_framebuffer_no_attachments must check for
     * the flag _HasAttachments and if GL_FALSE, must then
     * use the values in DefaultGeometry to initialize its
     * viewport, scissor and so on (in particular _Xmin, _Xmax,
     * _Ymin and _Ymax do NOT take into account _HasAttachments
-    * being false
+    * being false. To get the geometry of the framebuffer, the
+    * helper functions _mesa_geometric_width(), _mesa_geometric_height(),
+    * _mesa_geometric_samples() and _mesa_geometric_layers()
+    * are available that check _HasAttachments
     */
    GLboolean _HasAttachments;
 
-- 
1.9.1



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