+ /* viewport */
+ ctx->viewport.scale[0] = 0.5f * dst->width;
+ ctx->viewport.scale[1] = 0.5f * dst->height;
+ ctx->viewport.scale[2] = 0.5f;
+ ctx->viewport.scale[3] = 1.0f;
+ ctx->viewport.translate[0] = 0.5f * dst->width;
+ ctx->viewport.translate[1] = 0.5f * dst->height;
+ ctx->viewport.translate[2] = 0.5f;
+ ctx->viewport.translate[3] = 0.0f;
+ cso_set_viewport(ctx->cso, &ctx->viewport);
+