add tex_annotation!()

src/MakieTeX.jl

@@ -53,6 +53,8 @@ export LTeX
 export LaTeXStrings, LaTeXString, latexstring, @L_str
 export Typstry, TypstString, @typst_str
 
+export tex_annotation!
+
 "Try to write to `engine` and see what happens"
 function try_tex_engine(engine::Cmd)
     try

src/recipe.jl

@@ -143,3 +143,148 @@ function Makie.plot!(plot::TeXImg)
         markerspace = plot.markerspace,
     )
 end
+
+# CairoMakie direct drawing method
+function draw_tex(scene::Scene, screen::CairoMakie.Screen, cachedtex::CachedTeX, position::VecTypes, scale::VecTypes, rotation::Real, align::Tuple{Symbol, Symbol})
+    # establish some initial values
+    x0, y0 = 0.0, 0.0
+    w, h = cachedtex.dims
+    ctx = screen.context
+    # First we center the position with respect to the center of the image,
+    # regardless of its alignment.  This ensures that rotation takes place
+    # in the correct "axis" (2d).
+    position = position .+ (-scale[1]/2, scale[2]/2)
+
+
+    # Then, we find the appropriate "marker offset" w.r.t. alignment.
+    # This is separate because of Cairo's reversed y-axis.
+    halign, valign = align
+    pos = Point2f(0)
+    pos = if halign == :left
+        pos .- (-scale[1] / 2, 0)
+    elseif halign == :center
+        pos .- (0, 0)
+    elseif halign == :right
+        pos .- (scale[1] / 2, 0)
+    end
+
+    pos = if valign == :top
+        pos .+ (0, scale[2]/2)
+    elseif valign == :center
+        pos .+ (0, 0)
+    elseif valign == :bottom
+        pos .- (0, scale[2]/2)
+    end
+
+    # Calculate, with respect to the rotation, where the rotated center of the image
+    # should be.
+    # (Rotated center - Normal center)
+    cx = 0.5scale[1] * cos(rotation) - 0.5scale[2] * sin(rotation) - 0.5scale[1]
+    cy = 0.5scale[1] * sin(rotation) + 0.5scale[2] * cos(rotation) - 0.5scale[2]
+
+    # Begin the drawing and translation process
+    Cairo.save(ctx)
+    # translate to normal position
+    Cairo.translate(
+        ctx,
+        position[1],
+        position[2] - scale[2]
+    )
+    # rotate context by required rotation
+    Cairo.rotate(ctx, -rotation)
+    # cairo rotates around position as an axis,
+    #compensate for that with previously calculated values
+    Cairo.translate(ctx, cx, cy)
+    # apply "marker offset" to implement/simulate alignment
+    Cairo.translate(ctx, pos[1], pos[2])
+    # scale the marker appropriately
+    Cairo.scale(
+        ctx,
+        scale[1] / w,
+        scale[2] / h
+    )
+    # the rendering pipeline
+    # first is the "safe" Poppler pipeline, with better results in PDF
+    # and PNG, especially when rotated.
+    if !(RENDER_EXTRASAFE[])
+        # retrieve a new Poppler document pointer
+        document = update_pointer!(cachedtex)
+        # retrieve the first page
+        page = ccall(
+            (:poppler_document_get_page, Poppler_jll.libpoppler_glib),
+            Ptr{Cvoid},
+            (Ptr{Cvoid}, Cint),
+            document, 0 # page 0 is first page
+        )
+        # Render the page to the surface
+        ccall(
+            (:poppler_page_render, Poppler_jll.libpoppler_glib),
+            Cvoid,
+            (Ptr{Cvoid}, Ptr{Cvoid}),
+            page, ctx.ptr
+        )
+    else # "extra-safe" Cairo pipeline, also somewhat faster.
+        # render the cached CairoSurface to the screen.
+        # bad with PNG output though.
+        Cairo.set_source(ctx, cachedtex.surf, 0, 0)
+        Cairo.paint(ctx)
+    end
+    # restore context and end
+    Cairo.restore(ctx)
+end
+
+function CairoMakie.draw_plot(scene::Scene, screen::CairoMakie.Screen, img::T) where T <: MakieTeX.TeXImg
+
+    broadcast_foreach(img[1][], img.position[], img.scale[], CairoMakie.remove_billboard(img.rotations[]), img.align[]) do cachedtex, position, scale, rotation, align
+
+        w, h = cachedtex.dims
+
+        pos = CairoMakie.project_position(
+            scene, img.space[],
+            Makie.apply_transform(scene.transformation.transform_func[], position),
+            img.model[]
+        )
+
+        _w = scale * w; _h = scale * h
+        scale_factor = CairoMakie.project_scale(scene, img.space[], Vec2{Float32}(_w, _h), img.model[])
+
+        draw_tex(scene, screen, cachedtex, pos, scale_factor, rotation, align)
+
+    end
+
+end
+
+"""
+    tex_annotation!(axis::Axis, lstring, x, y; mainfont = nothing, mathfont = nothing, scale_factor=1)
+
+Add TeX annotation to an existing Makie Axis. Under the hood, it does a few things:
+
+1. via `mathspec` LaTeX package, we set the `mainfont` and `mathfont`
+2. Render it using `tectonic_jll` and convert to an image matrix.
+3. call `Makie.scatter!` and using the image as `marker`, scale the image by `scale_factor` while preserving aspec ratio.
+
+    !!! note
+You can use `\textcolor` from `xcolor` inside the latex string.
+"""
+function tex_annotation!(axis::Axis, lstring, x, y; mainfont = nothing, mathfont = nothing, scale_factor=1)
+    texdoc = TeXDocument(
+        String(lstring), true;
+        requires = "\\RequirePackage{luatex85}",
+        preamble = """
+        \\usepackage{amsmath, xcolor}
+        \\usepackage{mathspec}
+        \\pagestyle{empty}
+        $(isnothing(mainfont) ? "" :
+        "\\setmainfont{$mainfont}[Scale=MatchLowercase, Ligatures=TeX]"
+       )
+        $(isnothing(mathfont) ? "" :
+        "\\setmathfont(Digits,Latin)[Scale=MatchLowercase]{$mathfont}"
+       )
+        """,
+        class = "standalone",
+        classoptions = "preview, tightpage, 12pt"
+    )
+    tex = CachedTeX(texdoc)
+    marker = MakieTeX.rotl90(MakieTeX.recordsurf2img(tex, 4))
+    scatter!(axis, x, y; marker, markersize=tex.dims .* scale_factor)
+end