+ struct gl_framebuffer *fb = smesa->glCtx->DrawBuffer;
+
+ if (!smesa->front.Base.InternalFormat) {
+ /* do one-time init for the renderbuffers */
+ sisInitRenderbuffer(&smesa->front.Base, GL_RGBA);
+ sisSetSpanFunctions(&smesa->front, &fb->Visual);
+ _mesa_add_renderbuffer(fb, BUFFER_FRONT_LEFT, &smesa->front.Base);
+
+ if (fb->Visual.doubleBufferMode) {
+ sisInitRenderbuffer(&smesa->back.Base, GL_RGBA);
+ sisSetSpanFunctions(&smesa->back, &fb->Visual);
+ _mesa_add_renderbuffer(fb, BUFFER_BACK_LEFT, &smesa->back.Base);
+ }
+
+ if (smesa->glCtx->Visual.depthBits > 0) {
+ sisInitRenderbuffer(&smesa->depth.Base,
+ (smesa->glCtx->Visual.depthBits == 16
+ ? GL_DEPTH_COMPONENT16 : GL_DEPTH_COMPONENT24));
+ sisSetSpanFunctions(&smesa->depth, &fb->Visual);
+ _mesa_add_renderbuffer(fb, BUFFER_DEPTH, &smesa->depth.Base);
+ }
+
+ if (smesa->glCtx->Visual.stencilBits > 0) {
+ sisInitRenderbuffer(&smesa->stencil.Base, GL_STENCIL_INDEX8_EXT);
+ sisSetSpanFunctions(&smesa->stencil, &fb->Visual);
+ _mesa_add_renderbuffer(fb, BUFFER_STENCIL, &smesa->stencil.Base);
+ }
+ }
+
+ /* Make sure initialization did what we think it should */
+ assert(smesa->front.Base.InternalFormat);
+ assert(smesa->front.Base.AllocStorage);
+ if (fb->Visual.doubleBufferMode) {
+ assert(fb->Attachment[BUFFER_BACK_LEFT].Renderbuffer);
+ assert(smesa->front.Base.AllocStorage);
+ }
+ if (fb->Visual.depthBits) {
+ assert(fb->Attachment[BUFFER_DEPTH].Renderbuffer);
+ assert(smesa->depth.Base.AllocStorage);
+ }