Reduce retained stroke preview helper surface

src/legacy_canvas_stroke_preview_services.h

@@ -5,11 +5,6 @@
 
 namespace pp::panopainter {
 
-struct LegacyStrokePreviewCopySize {
-    int width = 0;
-    int height = 0;
-};
-
 struct LegacyVrColorUniforms {
     glm::vec4 color { 1.0f };
     glm::mat4 mvp { 1.0f };
@@ -40,24 +35,6 @@ inline void setup_legacy_vr_stroke_preview_shader(const LegacyVrStrokePreviewUni
     ShaderManager::u_mat4(kShaderUniform::MVP, uniforms.mvp);
 }
 
-template <
-    typename SetupCheckerboard,
-    typename DrawPlane,
-    typename BindBackgroundTexture,
-    typename CopyFramebufferToTexture>
-void execute_legacy_stroke_preview_background_capture(
-    SetupCheckerboard&& setup_checkerboard,
-    DrawPlane&& draw_plane,
-    BindBackgroundTexture&& bind_background_texture,
-    CopyFramebufferToTexture&& copy_framebuffer_to_texture,
-    LegacyStrokePreviewCopySize copy_size)
-{
-    setup_checkerboard();
-    draw_plane();
-    bind_background_texture();
-    copy_framebuffer_to_texture(0, 0, 0, 0, copy_size.width, copy_size.height);
-}
-
 template <
     typename SetupCompositeShader,
     typename BindCompositeSamplers,
@@ -100,14 +77,4 @@ void execute_legacy_stroke_preview_live_pass(
     copy_preview_result();
 }
 
-template <typename BindPreviewTexture, typename CopyFramebufferToTexture>
-void copy_legacy_stroke_preview_texture(
-    BindPreviewTexture&& bind_preview_texture,
-    CopyFramebufferToTexture&& copy_framebuffer_to_texture,
-    LegacyStrokePreviewCopySize copy_size)
-{
-    bind_preview_texture();
-    copy_framebuffer_to_texture(0, 0, 0, 0, copy_size.width, copy_size.height);
-}
-
 } // namespace pp::panopainter