renderbuffer.c

Mesa is an open-source implementation of the OpenGL specification - a system for rendering interacti

         continue;
      else if (b == BUFFER_BACK_LEFT && !backLeft)
         continue;
      else if (b == BUFFER_FRONT_RIGHT && !frontRight)
         continue;
      else if (b == BUFFER_BACK_RIGHT && !backRight)
         continue;

      /* the RGB buffer to wrap must already exist!! */
      assert(fb->Attachment[b].Renderbuffer);

      /* only GLubyte supported for now */
      assert(fb->Attachment[b].Renderbuffer->DataType == GL_UNSIGNED_BYTE);

      /* allocate alpha renderbuffer */
      arb = _mesa_new_renderbuffer(ctx, 0);
      if (!arb) {
         _mesa_error(ctx, GL_OUT_OF_MEMORY, "Allocating alpha buffer");
         return GL_FALSE;
      }

      /* wrap the alpha renderbuffer around the RGB renderbuffer */
      arb->Wrapped = fb->Attachment[b].Renderbuffer;

      /* Set up my alphabuffer fields and plug in my functions.
       * The functions will put/get the alpha values from/to RGBA arrays
       * and then call the wrapped buffer's functions to handle the RGB
       * values.
       */
      arb->InternalFormat = arb->Wrapped->InternalFormat;
      arb->_ActualFormat  = GL_ALPHA8;
      arb->_BaseFormat    = arb->Wrapped->_BaseFormat;
      arb->DataType       = arb->Wrapped->DataType;
      arb->AllocStorage   = alloc_storage_alpha8;
      arb->Delete         = delete_renderbuffer_alpha8;
      arb->GetPointer     = get_pointer_alpha8;
      arb->GetRow         = get_row_alpha8;
      arb->GetValues      = get_values_alpha8;
      arb->PutRow         = put_row_alpha8;
      arb->PutRowRGB      = put_row_rgb_alpha8;
      arb->PutMonoRow     = put_mono_row_alpha8;
      arb->PutValues      = put_values_alpha8;
      arb->PutMonoValues  = put_mono_values_alpha8;

      /* clear the pointer to avoid assertion/sanity check failure later */
      fb->Attachment[b].Renderbuffer = NULL;

      /* plug the alpha renderbuffer into the colorbuffer attachment */
      _mesa_add_renderbuffer(fb, b, arb);
   }

   return GL_TRUE;
}


/**
 * For framebuffers that use a software alpha channel wrapper
 * created by _mesa_add_alpha_renderbuffer or _mesa_add_soft_renderbuffers,
 * copy the back buffer alpha channel into the front buffer alpha channel.
 */
void
_mesa_copy_soft_alpha_renderbuffers(GLcontext *ctx, struct gl_framebuffer *fb)
{
   if (fb->Attachment[BUFFER_FRONT_LEFT].Renderbuffer &&
       fb->Attachment[BUFFER_BACK_LEFT].Renderbuffer)
      copy_buffer_alpha8(fb->Attachment[BUFFER_FRONT_LEFT].Renderbuffer,
                         fb->Attachment[BUFFER_BACK_LEFT].Renderbuffer);


   if (fb->Attachment[BUFFER_FRONT_RIGHT].Renderbuffer &&
       fb->Attachment[BUFFER_BACK_RIGHT].Renderbuffer)
      copy_buffer_alpha8(fb->Attachment[BUFFER_FRONT_RIGHT].Renderbuffer,
                         fb->Attachment[BUFFER_BACK_RIGHT].Renderbuffer);
}


/**
 * Add a software-based depth renderbuffer to the given framebuffer.
 * This is a helper routine for device drivers when creating a
 * window system framebuffer (not a user-created render/framebuffer).
 * Once this function is called, you can basically forget about this
 * renderbuffer; core Mesa will handle all the buffer management and
 * rendering!
 */
GLboolean
_mesa_add_depth_renderbuffer(GLcontext *ctx, struct gl_framebuffer *fb,
                             GLuint depthBits)
{
   struct gl_renderbuffer *rb;

   if (depthBits > 32) {
      _mesa_problem(ctx,
                    "Unsupported depthBits in _mesa_add_depth_renderbuffer");
      return GL_FALSE;
   }

   assert(fb->Attachment[BUFFER_DEPTH].Renderbuffer == NULL);

   rb = _mesa_new_renderbuffer(ctx, 0);
   if (!rb) {
      _mesa_error(ctx, GL_OUT_OF_MEMORY, "Allocating depth buffer");
      return GL_FALSE;
   }

   if (depthBits <= 16) {
      rb->_ActualFormat = GL_DEPTH_COMPONENT16;
   }
   else if (depthBits <= 24) {
      rb->_ActualFormat = GL_DEPTH_COMPONENT24;
   }
   else {
      rb->_ActualFormat = GL_DEPTH_COMPONENT32;
   }
   rb->InternalFormat = rb->_ActualFormat;

   rb->AllocStorage = _mesa_soft_renderbuffer_storage;
   _mesa_add_renderbuffer(fb, BUFFER_DEPTH, rb);

   return GL_TRUE;
}


/**
 * Add a software-based stencil renderbuffer to the given framebuffer.
 * This is a helper routine for device drivers when creating a
 * window system framebuffer (not a user-created render/framebuffer).
 * Once this function is called, you can basically forget about this
 * renderbuffer; core Mesa will handle all the buffer management and
 * rendering!
 */
GLboolean
_mesa_add_stencil_renderbuffer(GLcontext *ctx, struct gl_framebuffer *fb,
                               GLuint stencilBits)
{
   struct gl_renderbuffer *rb;

   if (stencilBits > 16) {
      _mesa_problem(ctx,
                  "Unsupported stencilBits in _mesa_add_stencil_renderbuffer");
      return GL_FALSE;
   }

   assert(fb->Attachment[BUFFER_STENCIL].Renderbuffer == NULL);

   rb = _mesa_new_renderbuffer(ctx, 0);
   if (!rb) {
      _mesa_error(ctx, GL_OUT_OF_MEMORY, "Allocating stencil buffer");
      return GL_FALSE;
   }

   if (stencilBits <= 8) {
      rb->_ActualFormat = GL_STENCIL_INDEX8_EXT;
   }
   else {
      /* not really supported (see s_stencil.c code) */
      rb->_ActualFormat = GL_STENCIL_INDEX16_EXT;
   }
   rb->InternalFormat = rb->_ActualFormat;

   rb->AllocStorage = _mesa_soft_renderbuffer_storage;
   _mesa_add_renderbuffer(fb, BUFFER_STENCIL, rb);

   return GL_TRUE;
}


/**
 * Add a software-based accumulation renderbuffer to the given framebuffer.
 * This is a helper routine for device drivers when creating a
 * window system framebuffer (not a user-created render/framebuffer).
 * Once this function is called, you can basically forget about this
 * renderbuffer; core Mesa will handle all the buffer management and
 * rendering!
 */
GLboolean
_mesa_add_accum_renderbuffer(GLcontext *ctx, struct gl_framebuffer *fb,
                             GLuint redBits, GLuint greenBits,
                             GLuint blueBits, GLuint alphaBits)
{
   struct gl_renderbuffer *rb;

   if (redBits > 16 || greenBits > 16 || blueBits > 16 || alphaBits > 16) {
      _mesa_problem(ctx,
                    "Unsupported accumBits in _mesa_add_accum_renderbuffer");
      return GL_FALSE;
   }

   assert(fb->Attachment[BUFFER_ACCUM].Renderbuffer == NULL);

   rb = _mesa_new_renderbuffer(ctx, 0);
   if (!rb) {
      _mesa_error(ctx, GL_OUT_OF_MEMORY, "Allocating accum buffer");
      return GL_FALSE;
   }

   rb->_ActualFormat = GL_RGBA16;
   rb->InternalFormat = GL_RGBA16;
   rb->AllocStorage = _mesa_soft_renderbuffer_storage;
   _mesa_add_renderbuffer(fb, BUFFER_ACCUM, rb);

   return GL_TRUE;
}



/**
 * Add a software-based accumulation renderbuffer to the given framebuffer.
 * This is a helper routine for device drivers when creating a
 * window system framebuffer (not a user-created render/framebuffer).
 * Once this function is called, you can basically forget about this
 * renderbuffer; core Mesa will handle all the buffer management and
 * rendering!
 *
 * NOTE: color-index aux buffers not supported.
 */
GLboolean
_mesa_add_aux_renderbuffers(GLcontext *ctx, struct gl_framebuffer *fb,
                            GLuint colorBits, GLuint numBuffers)
{
   GLuint i;

   if (colorBits > 16) {
      _mesa_problem(ctx,
                    "Unsupported accumBits in _mesa_add_aux_renderbuffers");
      return GL_FALSE;
   }

   assert(numBuffers < MAX_AUX_BUFFERS);

   for (i = 0; i < numBuffers; i++) {
      struct gl_renderbuffer *rb = _mesa_new_renderbuffer(ctx, 0);

      assert(fb->Attachment[BUFFER_AUX0 + i].Renderbuffer == NULL);

      if (!rb) {
         _mesa_error(ctx, GL_OUT_OF_MEMORY, "Allocating accum buffer");
         return GL_FALSE;
      }

      if (colorBits <= 8) {
         rb->_ActualFormat = GL_RGBA8;
      }
      else {
         rb->_ActualFormat = GL_RGBA16;
      }
      rb->InternalFormat = rb->_ActualFormat;

      rb->AllocStorage = _mesa_soft_renderbuffer_storage;
      _mesa_add_renderbuffer(fb, BUFFER_AUX0 + i, rb);
   }
   return GL_TRUE;
}


/**
 * Create/attach software-based renderbuffers to the given framebuffer.
 * This is a helper routine for device drivers.  Drivers can just as well
 * call the individual _mesa_add_*_renderbuffer() routines directly.
 */
void
_mesa_add_soft_renderbuffers(struct gl_framebuffer *fb,
                             GLboolean color,
                             GLboolean depth,
                             GLboolean stencil,
                             GLboolean accum,
                             GLboolean alpha,
                             GLboolean aux)
{
   GLboolean frontLeft = GL_TRUE;
   GLboolean backLeft = fb->Visual.doubleBufferMode;
   GLboolean frontRight = fb->Visual.stereoMode;
   GLboolean backRight = fb->Visual.stereoMode && fb->Visual.doubleBufferMode;

   if (color) {
      if (fb->Visual.rgbMode) {
         assert(fb->Visual.redBits == fb->Visual.greenBits);
         assert(fb->Visual.redBits == fb->Visual.blueBits);
         _mesa_add_color_renderbuffers(NULL, fb,
                                       fb->Visual.redBits,
                                       fb->Visual.alphaBits,
                                       frontLeft, backLeft,
                                       frontRight, backRight);
      }
      else {
         _mesa_add_color_index_renderbuffers(NULL, fb,
                                             fb->Visual.indexBits,
                                             frontLeft, backLeft,
                                             frontRight, backRight);
      }
   }

   if (depth) {
      assert(fb->Visual.depthBits > 0);
      _mesa_add_depth_renderbuffer(NULL, fb, fb->Visual.depthBits);
   }

   if (stencil) {
      assert(fb->Visual.stencilBits > 0);
      _mesa_add_stencil_renderbuffer(NULL, fb, fb->Visual.stencilBits);
   }

   if (accum) {
      assert(fb->Visual.rgbMode);
      assert(fb->Visual.accumRedBits > 0);
      assert(fb->Visual.accumGreenBits > 0);
      assert(fb->Visual.accumBlueBits > 0);
      _mesa_add_accum_renderbuffer(NULL, fb,
                                   fb->Visual.accumRedBits,
                                   fb->Visual.accumGreenBits,
                                   fb->Visual.accumBlueBits,
                                   fb->Visual.accumAlphaBits);
   }

   if (aux) {
      assert(fb->Visual.rgbMode);
      assert(fb->Visual.numAuxBuffers > 0);
      _mesa_add_aux_renderbuffers(NULL, fb, fb->Visual.redBits,
                                  fb->Visual.numAuxBuffers);
   }

   if (alpha) {
      assert(fb->Visual.rgbMode);
      assert(fb->Visual.alphaBits > 0);
      _mesa_add_alpha_renderbuffers(NULL, fb, fb->Visual.alphaBits,
                                    frontLeft, backLeft,
                                    frontRight, backRight);
   }

#if 0
   if (multisample) {
      /* maybe someday */
   }
#endif
}


/**
 * Attach a renderbuffer to a framebuffer.
 */
void
_mesa_add_renderbuffer(struct gl_framebuffer *fb,
                       GLuint bufferName, struct gl_renderbuffer *rb)
{
   assert(fb);
   assert(rb);
   assert(bufferName < BUFFER_COUNT);

   /* There should be no previous renderbuffer on this attachment point,
    * with the exception of depth/stencil since the same renderbuffer may
    * be used for both.
    */
   assert(bufferName == BUFFER_DEPTH ||
          bufferName == BUFFER_STENCIL ||
          fb->Attachment[bufferName].Renderbuffer == NULL);

   /* winsys vs. user-created buffer cross check */
   if (fb->Name) {
      assert(rb->Name);
   }
   else {
      assert(!rb->Name);
   }

   /* If Mesa's compiled with deep color channels (16 or 32 bits / channel)
    * and the device driver is expecting 8-bit values (GLubyte), we can
    * use a "renderbuffer adaptor/wrapper" to do the necessary conversions.
    */
   if (rb->_BaseFormat == GL_RGBA) {
      if (CHAN_BITS == 16 && rb->DataType == GL_UNSIGNED_BYTE) {
         GET_CURRENT_CONTEXT(ctx);
         rb = _mesa_new_renderbuffer_16wrap8(ctx, rb);
      }
      else if (CHAN_BITS == 32 && rb->DataType == GL_UNSIGNED_BYTE) {
         GET_CURRENT_CONTEXT(ctx);
         rb = _mesa_new_renderbuffer_32wrap8(ctx, rb);
      }
      else if (CHAN_BITS == 32 && rb->DataType == GL_UNSIGNED_SHORT) {
         GET_CURRENT_CONTEXT(ctx);
         rb = _mesa_new_renderbuffer_32wrap16(ctx, rb);
      }
   }

   fb->Attachment[bufferName].Type = GL_RENDERBUFFER_EXT;
   fb->Attachment[bufferName].Complete = GL_TRUE;
   _mesa_reference_renderbuffer(&fb->Attachment[bufferName].Renderbuffer, rb);
}


/**
 * Remove the named renderbuffer from the given framebuffer.
 */
void
_mesa_remove_renderbuffer(struct gl_framebuffer *fb, GLuint bufferName)
{
   struct gl_renderbuffer *rb;

   assert(bufferName < BUFFER_COUNT);

   rb = fb->Attachment[bufferName].Renderbuffer;
   if (!rb)
      return;

   _mesa_reference_renderbuffer(&rb, NULL);

   fb->Attachment[bufferName].Renderbuffer = NULL;
}


/**
 * Set *ptr to point to rb.  If *ptr points to another renderbuffer,
 * dereference that buffer first.  The new renderbuffer's refcount will
 * be incremented.  The old renderbuffer's refcount will be decremented.
 */
void
_mesa_reference_renderbuffer(struct gl_renderbuffer **ptr,
                             struct gl_renderbuffer *rb)
{
   assert(ptr);
   if (*ptr == rb) {
      /* no change */
      return;
   }

   if (*ptr) {
      /* Unreference the old renderbuffer */
      GLboolean deleteFlag = GL_FALSE;
      struct gl_renderbuffer *oldRb = *ptr;

      assert(oldRb->Magic == RB_MAGIC);
      _glthread_LOCK_MUTEX(o