chore(deps): bump actions/setup-python from 6 to 7

Bumps [actions/setup-python](https://github.com/actions/setup-python) from 6 to 7.
- [Release notes](https://github.com/actions/setup-python/releases)
- [Commits](https://github.com/actions/setup-python/compare/v6...v7)

---
updated-dependencies:
- dependency-name: actions/setup-python
  dependency-version: '7'
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <support@github.com>

.github/workflows/update-translation.yml

@@ -13,7 +13,7 @@ jobs:
         uses: actions/checkout@v7
 
       - name: Setup Python
-        uses: actions/setup-python@v6
+        uses: actions/setup-python@v7
         with:
           python-version: '3.12'
 

resources/shaders/140/gouraud.fs

@@ -1,4 +1,7 @@
 #version 140
+// Multisample depth texture for the anti-aliased outline (see 3DScene.cpp render_with_outline).
+// Optional on the GLSL 140 path: if unavailable, fallback to a non-multisample depth texture.
+#extension GL_ARB_texture_multisample : enable
 
 const vec3 ZERO = vec3(0.0, 0.0, 0.0);
 //BBS: add grey and orange
@@ -36,7 +39,14 @@ uniform SlopeDetection slope;
 
 //BBS: add outline_color
 uniform bool is_outline;
+// The outline is a per-fragment discard mask, which the framebuffer MSAA cannot smooth, so the
+// silhouette is resolved per sample from a multisample copy of the outlined model's depth buffer.
+#ifdef GL_ARB_texture_multisample
+uniform sampler2DMS depth_tex;
+uniform int msaa_samples; // samples in depth_tex, 1 when MSAA is off
+#else
 uniform sampler2D depth_tex;
+#endif
 uniform vec2 screen_size;
 
 #ifdef ENABLE_ENVIRONMENT_MAP
@@ -99,7 +109,22 @@ float GetTolerance(float d, float k)
     return -k*(d+A)*(d+A)/B;   
 }
 
-float DetectSilho(vec2 fragCoord, vec2 dir)
+// Depth of sample s at integer pixel coord.
+#ifdef GL_ARB_texture_multisample
+float FetchDepth(ivec2 coord, int s)
+{
+    // texelFetch has no wrap mode, so clamp to the edge texel (sampler2D used CLAMP_TO_EDGE).
+    ivec2 sz = textureSize(depth_tex);
+    return abs(texelFetch(depth_tex, clamp(coord, ivec2(0), sz - 1), s).r);
+}
+#else
+float FetchDepth(ivec2 coord, int s)
+{
+    return abs(texture(depth_tex, (vec2(coord) + 0.5) / screen_size).r);
+}
+#endif
+
+float DetectSilho(ivec2 coord, ivec2 dir, int s)
 {
     // -------------------------------------------
     //   x0 ___ x1----o
@@ -112,11 +137,10 @@ float DetectSilho(vec2 fragCoord, vec2 dir)
     // and expected (as if x0..3 where on the same
     // plane) depth values.
     // -------------------------------------------
-    
-    float x0 = abs(texture(depth_tex, (fragCoord + dir*-2.0) / screen_size).r);
-    float x1 = abs(texture(depth_tex, (fragCoord + dir*-1.0) / screen_size).r);
-    float x2 = abs(texture(depth_tex, (fragCoord + dir* 0.0) / screen_size).r);
-    float x3 = abs(texture(depth_tex, (fragCoord + dir* 1.0) / screen_size).r);
+    float x0 = FetchDepth(coord + dir*-2, s);
+    float x1 = FetchDepth(coord + dir*-1, s);
+    float x2 = FetchDepth(coord,          s);
+    float x3 = FetchDepth(coord + dir* 1, s);
 
     float d0 = (x1-x0);
     float d1 = (x2-x3);
@@ -127,17 +151,45 @@ float DetectSilho(vec2 fragCoord, vec2 dir)
     float tol = GetTolerance(x2, 0.04);
 
     return smoothstep(0.0, tol*tol, max( - r0*r1, 0.0));
-
 }
 
-float DetectSilho(vec2 fragCoord)
+float DetectSilho(ivec2 coord, int s)
 {
     return max(
-        DetectSilho(fragCoord, vec2(1,0)), // Horizontal
-        DetectSilho(fragCoord, vec2(0,1))  // Vertical
+        DetectSilho(coord, ivec2(1,0), s), // Horizontal
+        DetectSilho(coord, ivec2(0,1), s)  // Vertical
         );
 }
 
+// Full response of one sample. Reduce the max() per sample and average only afterwards:
+// max(mean) <= mean(max), and averaging first hollows out diagonal and curved lines.
+float DetectSilhoSample(ivec2 coord, int s)
+{
+    float v = DetectSilho(coord, s);
+    // Makes silhouettes thicker.
+    for (int i = 1; i <= INFLATE; ++i)
+    {
+        v = max(v, DetectSilho(coord + ivec2(i, 0), s));
+        v = max(v, DetectSilho(coord + ivec2(0, i), s));
+    }
+    return v;
+}
+
+// Average the per-sample coverage into the sub-pixel anti-aliasing of the line.
+float DetectSilho(vec2 fragCoord)
+{
+    ivec2 coord = ivec2(fragCoord);
+#ifdef GL_ARB_texture_multisample
+    int n = max(msaa_samples, 1);
+#else
+    const int n = 1;
+#endif
+    float acc = 0.0;
+    for (int s = 0; s < n; ++s)
+        acc += DetectSilhoSample(coord, s);
+    return acc / float(n);
+}
+
 // Returns a lighting multiplier in [1 - shadow_intensity, 1]: < 1 where the fragment is
 // occluded from the light in the shadow map. 3x3 PCF softens the edges.
 float shadow_shade()
@@ -224,14 +276,7 @@ void main()
     //BBS: add outline_color
     if (is_outline) {
         color = vec4((vec3(intensity.y) + color.rgb * intensity.x) * shade, color.a);
-        vec2 fragCoord = gl_FragCoord.xy;
-        float s = DetectSilho(fragCoord);
-        // Makes silhouettes thicker.
-        for(int i=1;i<=INFLATE; i++)
-        {
-           s = max(s, DetectSilho(fragCoord.xy + vec2(i, 0)));
-           s = max(s, DetectSilho(fragCoord.xy + vec2(0, i)));
-        }
+        float s = DetectSilho(gl_FragCoord.xy);
         if (s < 0.01)
             discard;
         out_color = vec4(mix(color.rgb, getBackfaceColor(color.rgb), s), color.a);

resources/shaders/140/phong.fs

@@ -1,4 +1,7 @@
 #version 140
+// Multisample depth texture for the anti-aliased outline (see 3DScene.cpp render_with_outline).
+// Optional on the GLSL 140 path: if unavailable, fallback to a non-multisample depth texture.
+#extension GL_ARB_texture_multisample : enable
 
 const vec3 ZERO = vec3(0.0, 0.0, 0.0);
 const vec3 LightRed = vec3(0.78, 0.0, 0.0);
@@ -51,7 +54,14 @@ uniform SlopeDetection slope;
 
 //BBS: add outline_color
 uniform bool is_outline;
+// The outline is a per-fragment discard mask, which the framebuffer MSAA cannot smooth, so the
+// silhouette is resolved per sample from a multisample copy of the outlined model's depth buffer.
+#ifdef GL_ARB_texture_multisample
+uniform sampler2DMS depth_tex;
+uniform int msaa_samples; // samples in depth_tex, 1 when MSAA is off
+#else
 uniform sampler2D depth_tex;
+#endif
 uniform vec2 screen_size;
 
 #ifdef ENABLE_ENVIRONMENT_MAP
@@ -100,12 +110,27 @@ float GetTolerance(float d, float k)
     return -k*(d+A)*(d+A)/B;
 }
 
-float DetectSilho(vec2 fragCoord, vec2 dir)
+// Depth of sample s at integer pixel coord.
+#ifdef GL_ARB_texture_multisample
+float FetchDepth(ivec2 coord, int s)
 {
-    float x0 = abs(texture(depth_tex, (fragCoord + dir*-2.0) / screen_size).r);
-    float x1 = abs(texture(depth_tex, (fragCoord + dir*-1.0) / screen_size).r);
-    float x2 = abs(texture(depth_tex, (fragCoord + dir* 0.0) / screen_size).r);
-    float x3 = abs(texture(depth_tex, (fragCoord + dir* 1.0) / screen_size).r);
+    // texelFetch has no wrap mode, so clamp to the edge texel (sampler2D used CLAMP_TO_EDGE).
+    ivec2 sz = textureSize(depth_tex);
+    return abs(texelFetch(depth_tex, clamp(coord, ivec2(0), sz - 1), s).r);
+}
+#else
+float FetchDepth(ivec2 coord, int s)
+{
+    return abs(texture(depth_tex, (vec2(coord) + 0.5) / screen_size).r);
+}
+#endif
+
+float DetectSilho(ivec2 coord, ivec2 dir, int s)
+{
+    float x0 = FetchDepth(coord + dir*-2, s);
+    float x1 = FetchDepth(coord + dir*-1, s);
+    float x2 = FetchDepth(coord,          s);
+    float x3 = FetchDepth(coord + dir* 1, s);
 
     float d0 = (x1-x0);
     float d1 = (x2-x3);
@@ -116,17 +141,45 @@ float DetectSilho(vec2 fragCoord, vec2 dir)
     float tol = GetTolerance(x2, 0.04);
 
     return smoothstep(0.0, tol*tol, max( - r0*r1, 0.0));
-
 }
 
-float DetectSilho(vec2 fragCoord)
+float DetectSilho(ivec2 coord, int s)
 {
     return max(
-        DetectSilho(fragCoord, vec2(1,0)),
-        DetectSilho(fragCoord, vec2(0,1))
+        DetectSilho(coord, ivec2(1,0), s),
+        DetectSilho(coord, ivec2(0,1), s)
         );
 }
 
+// Full response of one sample. Reduce the max() per sample and average only afterwards:
+// max(mean) <= mean(max), and averaging first hollows out diagonal and curved lines.
+float DetectSilhoSample(ivec2 coord, int s)
+{
+    float v = DetectSilho(coord, s);
+    // Makes silhouettes thicker.
+    for (int i = 1; i <= INFLATE; ++i)
+    {
+        v = max(v, DetectSilho(coord + ivec2(i, 0), s));
+        v = max(v, DetectSilho(coord + ivec2(0, i), s));
+    }
+    return v;
+}
+
+// Average the per-sample coverage into the sub-pixel anti-aliasing of the line.
+float DetectSilho(vec2 fragCoord)
+{
+    ivec2 coord = ivec2(fragCoord);
+#ifdef GL_ARB_texture_multisample
+    int n = max(msaa_samples, 1);
+#else
+    const int n = 1;
+#endif
+    float acc = 0.0;
+    for (int s = 0; s < n; ++s)
+        acc += DetectSilhoSample(coord, s);
+    return acc / float(n);
+}
+
 float compute_ssao_factor(vec3 normal, vec3 view_dir, vec3 eye_pos)
 {
     vec3 normal_dx = dFdx(normal);
@@ -270,13 +323,7 @@ void main()
     if (is_outline) {
         vec3 shaded_rgb = (vec3(specular) + window_reflection + color.rgb * diffuse) * PHONG_BRIGHTNESS * shade;
         vec4 shaded_color = vec4(clamp(shaded_rgb, vec3(0.0), vec3(1.0)), color.a);
-        vec2 fragCoord = gl_FragCoord.xy;
-        float s = DetectSilho(fragCoord);
-        for(int i=1;i<=INFLATE; i++)
-        {
-           s = max(s, DetectSilho(fragCoord.xy + vec2(i, 0)));
-           s = max(s, DetectSilho(fragCoord.xy + vec2(0, i)));
-        }
+        float s = DetectSilho(gl_FragCoord.xy);
         if (s < 0.01)
             discard;
         out_color = vec4(mix(shaded_color.rgb, getBackfaceColor(shaded_color.rgb), s), shaded_color.a);

src/libslic3r/BoundingBox.hpp

@@ -25,7 +25,7 @@ public:
         min(p1), max(p1), defined(false) { merge(p2); merge(p3); }
 
     template<class It, class = IteratorOnly<It>>
-    BoundingBoxBase(It from, It to)
+    BoundingBoxBase(It from, It to) : BoundingBoxBase()
         { construct(*this, from, to); }
 
     BoundingBoxBase(const PointsType &points)

src/libslic3r/Fill/FillBase.cpp

@@ -1857,12 +1857,12 @@ static inline void base_support_extend_infill_lines(Polylines &infill, BoundaryI
         const bool                   first           = graph.first(cp);
         int                          extend_next_idx = -1;
         int                          extend_prev_idx = -1;
-        coord_t                      dist_y_prev;
-        coord_t                      dist_y_next;
-        double                       arc_len_prev;
-        double                       arc_len_next;
+        coord_t                      dist_y_prev     = 0;
+        coord_t                      dist_y_next     = 0;
+        double                       arc_len_prev    = 0;
+        double                       arc_len_next    = 0;
 
-        if (! graph.next_vertical(cp)){
+        if (! graph.next_vertical(cp)) {
             size_t i = cp.point_idx;
             size_t j = next_idx_modulo(i, contour);
             while (j != cp.next_on_contour->point_idx) {

src/libslic3r/GCode.hpp

@@ -184,7 +184,7 @@ struct LayerResult {
     // It is used for the pressure equalizer because it needs to buffer one layer back.
     bool        nop_layer_result { false };
 
-    static LayerResult make_nop_layer_result() { return {"", std::numeric_limits<coord_t>::max(), false, false, true}; }
+    static LayerResult make_nop_layer_result() { return {"", std::numeric_limits<size_t>::max(), false, false, true}; }
 };
 
 class GCode {

src/slic3r/GUI/3DScene.cpp

@@ -70,6 +70,9 @@ float FullTransparentModdifiedToFixAlpha = 0.3f;
 // value like 0.18f could not because in C++ (int)(0.18f * 255) == 45 however in OpenGL it renders this as 46
 // which breaks the `SelectMachineDialog::record_edge_pixels_data()` function!
 float FULL_BLACK_THRESHOLD = 0.2f;
+// Keep depth_tex away from texture unit 0 to avoid sampler-type aliasing with
+// shadow/environment samplers when realistic view is disabled.
+static constexpr int OUTLINE_DEPTH_TEX_UNIT = 5;
 
 Slic3r::ColorRGBA adjust_color_for_rendering(const Slic3r::ColorRGBA &colors)
 {
@@ -518,6 +521,37 @@ void GLVolume::render_with_outline(const GUI::Size& cnv_size)
     glsafe(::glStencilMask(0xFF));
     glsafe(::glDisable(GL_STENCIL_TEST));
     // render the outline using depth buffer and discard the pixels that are not on the outline
+    // The silhouette is resolved per sample in the shader (see DetectSilho in gouraud.fs/phong.fs).
+    // That needs the GL 3.2 entry points and a shader that declares depth_tex as sampler2DMS, which
+    // only the 140 ones do and only under GL_ARB_texture_multisample - so ask the compiled program
+    // rather than the GL version, or a sampler2D ends up bound to a multisample texture.
+    // Only the Arb branch below allocates a multisample texture, so keep the target consistent with it.
+    const bool  use_msaa_outline = framebuffers_type == GUI::OpenGLManager::EFramebufferType::Arb &&
+                                   GUI::wxGetApp().is_gl_version_greater_or_equal_to(3, 2) &&
+                                   shader->get_uniform_location("msaa_samples") >= 0;
+    const GLenum depth_tex_target = use_msaa_outline ? GL_TEXTURE_2D_MULTISAMPLE : GL_TEXTURE_2D;
+    // Keep the depth texture off image unit 0. The object shaders leave shadow_map (and
+    // environment_tex) at the default sampler value 0 whenever the shadow pass is skipped - which is
+    // the case with realistic view off - and GL forbids two sampler types referring to the same image
+    // unit. A sampler2DMS on unit 0 then makes every draw fail with INVALID_OPERATION on drivers that
+    // enforce it (Mesa), i.e. the model disappears entirely. Unit 5 is unused (shadow_map takes 4).
+    const int depth_tex_unit = OUTLINE_DEPTH_TEX_UNIT;
+    int aa_samples = 1;
+    if (use_msaa_outline) {
+        if (const AppConfig* app_config = GUI::wxGetApp().app_config; app_config != nullptr) {
+            const std::string value = app_config->get(SETTING_OPENGL_AA_SAMPLES);
+            if (value == "2" || value == "4" || value == "8" || value == "16")
+                aa_samples = ::atoi(value.c_str());
+        }
+        // Never request more samples than the driver supports for depth textures (a 1-sample texture
+        // is used when MSAA is disabled, keeping a single code path for the sampler2DMS shader).
+        GLint max_samples = 1;
+        glsafe(::glGetIntegerv(GL_MAX_DEPTH_TEXTURE_SAMPLES, &max_samples));
+        if (aa_samples > max_samples)
+            aa_samples = max_samples < 1 ? 1 : max_samples;
+        if (aa_samples < 1)
+            aa_samples = 1;
+    }
     // 1st. render pass, render the model into a separate render target that has only depth buffer
     GLuint depth_fbo   = 0;
     GLuint depth_tex = 0;
@@ -525,21 +559,26 @@ void GLVolume::render_with_outline(const GUI::Size& cnv_size)
         glsafe(::glGenFramebuffers(1, &depth_fbo));
         glsafe(::glBindFramebuffer(GL_FRAMEBUFFER, depth_fbo));
 
-        glActiveTexture(GL_TEXTURE0);
+        glsafe(::glActiveTexture(GL_TEXTURE0 + depth_tex_unit));
         glsafe(::glGenTextures(1, &depth_tex));
-        glsafe(::glBindTexture(GL_TEXTURE_2D, depth_tex));
-        glsafe(::glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE));
-        glsafe(::glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE));
-        glsafe(::glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR));
-        glsafe(::glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR));
-        glsafe(::glTexImage2D(GL_TEXTURE_2D, 0, GL_DEPTH_COMPONENT32F, cnv_size.get_width(), cnv_size.get_height(), 0, GL_DEPTH_COMPONENT, GL_FLOAT, nullptr));
+        glsafe(::glBindTexture(depth_tex_target, depth_tex));
+        if (use_msaa_outline) {
+            // Multisample textures do not take filter/wrap parameters.
+            glsafe(::glTexImage2DMultisample(GL_TEXTURE_2D_MULTISAMPLE, aa_samples, GL_DEPTH_COMPONENT32F, cnv_size.get_width(), cnv_size.get_height(), GL_TRUE));
+        } else {
+            glsafe(::glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE));
+            glsafe(::glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE));
+            glsafe(::glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR));
+            glsafe(::glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR));
+            glsafe(::glTexImage2D(GL_TEXTURE_2D, 0, GL_DEPTH_COMPONENT32F, cnv_size.get_width(), cnv_size.get_height(), 0, GL_DEPTH_COMPONENT, GL_FLOAT, nullptr));
+        }
 
-        glsafe(::glFramebufferTexture2D(GL_FRAMEBUFFER, GL_DEPTH_ATTACHMENT, GL_TEXTURE_2D, depth_tex, 0));
+        glsafe(::glFramebufferTexture2D(GL_FRAMEBUFFER, GL_DEPTH_ATTACHMENT, depth_tex_target, depth_tex, 0));
     } else {
         glsafe(::glGenFramebuffersEXT(1, &depth_fbo));
         glsafe(::glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, depth_fbo));
 
-        glActiveTexture(GL_TEXTURE0);
+        glsafe(::glActiveTexture(GL_TEXTURE0 + depth_tex_unit));
         glsafe(::glGenTextures(1, &depth_tex));
         glsafe(::glBindTexture(GL_TEXTURE_2D, depth_tex));
         glsafe(::glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE));
@@ -550,12 +589,15 @@ void GLVolume::render_with_outline(const GUI::Size& cnv_size)
 
         glsafe(::glFramebufferTexture2DEXT(GL_FRAMEBUFFER_EXT, GL_DEPTH_ATTACHMENT_EXT, GL_TEXTURE_2D, depth_tex, 0));
     }
+    // Unbind before drawing: the texture is this framebuffer's depth attachment, so leaving it bound
+    // to a sampled unit would be a feedback loop.
+    glsafe(::glBindTexture(depth_tex_target, 0));
+    glsafe(::glActiveTexture(GL_TEXTURE0));
     glsafe(::glClear(GL_DEPTH_BUFFER_BIT));
     if (tverts_range == std::make_pair<size_t, size_t>(0, -1))
         model.render(shader);
     else
         model.render(this->tverts_range, shader);
-    glsafe(::glBindTexture(GL_TEXTURE_2D, 0));
 
     // 2nd. render pass, just a normal render with the depth buffer passed as a texture
     if (framebuffers_type == GUI::OpenGLManager::EFramebufferType::Arb) {
@@ -565,13 +607,17 @@ void GLVolume::render_with_outline(const GUI::Size& cnv_size)
     }
     shader->set_uniform("is_outline", true);
     shader->set_uniform("screen_size", Vec2f{cnv_size.get_width(), cnv_size.get_height()});
-    glActiveTexture(GL_TEXTURE0);
-    glsafe(::glBindTexture(GL_TEXTURE_2D, depth_tex));
-    shader->set_uniform("depth_tex", 0);
+    shader->set_uniform("msaa_samples", aa_samples);
+    glsafe(::glActiveTexture(GL_TEXTURE0 + depth_tex_unit));
+    glsafe(::glBindTexture(depth_tex_target, depth_tex));
+    glsafe(::glActiveTexture(GL_TEXTURE0));
+    shader->set_uniform("depth_tex", depth_tex_unit);
     simple_render(shader, model_objects, colors);
 
     // Some clean up to do
-    glsafe(::glBindTexture(GL_TEXTURE_2D, 0));
+    glsafe(::glActiveTexture(GL_TEXTURE0 + depth_tex_unit));
+    glsafe(::glBindTexture(depth_tex_target, 0));
+    glsafe(::glActiveTexture(GL_TEXTURE0));
     shader->set_uniform("is_outline", false);
     if (framebuffers_type == GUI::OpenGLManager::EFramebufferType::Arb) {
         glsafe(::glBindFramebuffer(GL_FRAMEBUFFER, 0));
@@ -1075,6 +1121,10 @@ void GLVolumeCollection::render(GLVolumeCollection::ERenderType       type,
 
     const float support_normal_z = get_selection_support_normal_z();
 
+    // Prime depth_tex on every frame so non-outline draws do not keep the
+    // default sampler unit 0, which can conflict with other sampler types.
+    shader->set_uniform("depth_tex", OUTLINE_DEPTH_TEX_UNIT);
+
     for (GLVolumeWithIdAndZ& volume : to_render) {
 #if ENABLE_MODIFIERS_ALWAYS_TRANSPARENT
         if (type == ERenderType::Transparent) {

src/slic3r/GUI/GUI_Utils.cpp

@@ -548,7 +548,7 @@ void RemoveButtonBorder(wxWindow* win)
     GtkCssProvider* provider = gtk_css_provider_new();
 
     const char* css =
-        "button {"
+        "button, button:hover, button:active, button:focus {"
         "  border: none;"
         "  outline: none;"
         "  box-shadow: none;"
@@ -589,6 +589,58 @@ void RemoveButtonBorder(wxWindow* win)
     );
 #endif
 }
+
+void RemoveInputBorder(wxWindow* win)
+{
+    GtkWidget* widget = win->GetHandle();
+    if (!widget) return;
+
+#if GTK_CHECK_VERSION(3, 0, 0)
+    // GTK3+: use CSS provider
+    GtkCssProvider* provider = gtk_css_provider_new();
+
+    // Target 'entry' and its inner subnodes (like text selection areas)
+    const char* css =
+        "entry, entry text, entry undershoot {"
+        "  border: none;"
+        "  outline: none;"
+        "  box-shadow: none;"
+        "  padding: 0px;"
+        "  margin: 0px;"
+        "  min-height: 0px;"
+        "  min-width: 0px;"
+        "  background: none;"
+        "}";
+
+#if GTK_CHECK_VERSION(4, 0, 0)
+    // GTK4
+    gtk_css_provider_load_from_data(provider, css, -1);
+#else
+    // GTK3
+    gtk_css_provider_load_from_data(provider, css, -1, nullptr);
+#endif
+
+    GtkStyleContext* ctx = gtk_widget_get_style_context(widget);
+    gtk_style_context_add_provider(
+        ctx,
+        GTK_STYLE_PROVIDER(provider),
+        GTK_STYLE_PROVIDER_PRIORITY_USER
+    );
+    g_object_unref(provider);
+
+#else
+    // GTK2: Target the x/y thickness of the entry widget
+    gtk_rc_parse_string(
+        "style \"no-padding-entry\" {"
+        "  xthickness = 0"
+        "  ythickness = 0"
+        "  GtkEntry::inner-border = { 0, 0, 0, 0 }"
+        "  GtkEntry::focus-line-width = 0"
+        "}"
+        "class \"GtkEntry\" style \"no-padding-entry\""
+    );
+#endif
+}
 #endif // __WXGTK__
 
 #ifdef __linux__

src/slic3r/GUI/GUI_Utils.hpp

@@ -472,8 +472,9 @@ void dataview_remove_insets(wxDataViewCtrl* dv);
 void staticbox_remove_margin(wxStaticBox* sb);
 #endif
 
-#ifdef __WXGTK3__
-void RemoveButtonBorder(wxWindow* win);
+#ifdef __WXGTK__
+void RemoveButtonBorder(wxWindow* win);   // for wxButton/wxBitmapToggleButton based controls (SwitchButton, CheckBox)
+void RemoveInputBorder(wxWindow* win);    // for TextCtrl based controls (TextInput, ComboBox, SpinInput..)
 #endif
 
 #if defined(__WXOSX__) || defined(__linux__)

src/slic3r/GUI/PresetComboBoxes.cpp

@@ -865,6 +865,9 @@ PlaterPresetComboBox::PlaterPresetComboBox(wxWindow *parent, Preset::Type preset
         clr_picker = new wxBitmapButton(parent, wxID_ANY, {}, wxDefaultPosition, wxSize(FromDIP(20), FromDIP(20)), wxBU_EXACTFIT | wxBU_AUTODRAW | wxBORDER_NONE);
         clr_picker->SetBackgroundColour(StateColor::darkModeColorFor(*wxWHITE));
         clr_picker->SetToolTip(_L("Click to select filament color"));
+#ifdef __WXGTK__
+        RemoveButtonBorder(clr_picker);
+#endif
         clr_picker->Bind(wxEVT_BUTTON, [this](wxCommandEvent& e) {
             // Check if it's an official filament
             auto fila_type = Preset::remove_suffix_modified(GetValue().ToUTF8().data());

src/slic3r/GUI/Widgets/CheckBox.cpp

@@ -2,7 +2,7 @@
 
 #include "../wxExtensions.hpp"
 
-#ifdef __WXGTK3__
+#ifdef __WXGTK__
 #include "../GUI_Utils.hpp"
 #endif
 
@@ -29,7 +29,7 @@ CheckBox::CheckBox(wxWindow *parent, int id)
     Bind(wxEVT_LEAVE_WINDOW, &CheckBox::updateBitmap, this);
 #endif
 
-#ifdef __WXGTK3__
+#ifdef __WXGTK__
     Slic3r::GUI::RemoveButtonBorder(this);
 #endif
 

src/slic3r/GUI/Widgets/RadioBox.cpp

@@ -2,6 +2,10 @@
 
 #include "../wxExtensions.hpp"
 
+#ifdef __WXGTK__
+#include "../GUI_Utils.hpp"
+#endif
+
 namespace Slic3r {
 namespace GUI {
 RadioBox::RadioBox(wxWindow *parent)
@@ -15,6 +19,7 @@ RadioBox::RadioBox(wxWindow *parent)
     // Bind(wxEVT_TOGGLEBUTTON, [this](auto& e) { update(); e.Skip(); });
     update();
 #ifdef __WXGTK__
+    Slic3r::GUI::RemoveButtonBorder(this);
     wxSize bestSize = GetBestSize();
     bestSize.IncTo(m_on.GetBmpSize());
     SetSize(bestSize);

src/slic3r/GUI/Widgets/SpinInput.cpp

@@ -5,6 +5,10 @@
 
 #include <wx/dcgraph.h>
 
+#ifdef __WXGTK__
+#include "../GUI_Utils.hpp"
+#endif
+
 BEGIN_EVENT_TABLE(SpinInput, StaticBox)
 
 EVT_KEY_DOWN(SpinInput::keyPressed)
@@ -58,6 +62,11 @@ void SpinInput::Create(wxWindow *parent,
     state_handler.attach({&label_color, &text_color});
     state_handler.update_binds();
     text_ctrl = new TextCtrl(this, wxID_ANY, text, {20, 4}, wxDefaultSize, style | wxBORDER_NONE | wxTE_PROCESS_ENTER, wxTextValidator(wxFILTER_DIGITS));
+
+#ifdef __WXGTK__
+    Slic3r::GUI::RemoveInputBorder(text_ctrl);
+#endif
+
     text_ctrl->SetFont(Label::Body_14);
     text_ctrl->SetBackgroundColour(background_color.colorForStates(state_handler.states()));
     text_ctrl->SetForegroundColour(text_color.colorForStates(state_handler.states()));

src/slic3r/GUI/Widgets/SwitchButton.cpp

@@ -12,7 +12,7 @@
 #include "libslic3r/MacUtils.hpp"
 #endif
 
-#ifdef __WXGTK3__
+#ifdef __WXGTK__
 #include "../GUI_Utils.hpp"
 #endif
 
@@ -37,7 +37,7 @@ SwitchButton::SwitchButton(wxWindow* parent, wxWindowID id)
 	Bind(wxEVT_TOGGLEBUTTON, [this](auto& e) { update(); e.Skip(); });
 	SetFont(Label::Body_12);
 
-#ifdef __WXGTK3__
+#ifdef __WXGTK__
     Slic3r::GUI::RemoveButtonBorder(this);
 #endif
 

src/slic3r/GUI/Widgets/TextInput.cpp

@@ -6,6 +6,10 @@
 #include <wx/dcclient.h>
 #include <wx/dcgraph.h>
 
+#ifdef __WXGTK__
+#include "../GUI_Utils.hpp"
+#endif
+
 BEGIN_EVENT_TABLE(TextInput, StaticBox)
 
 EVT_PAINT(TextInput::paintEvent)
@@ -60,6 +64,11 @@ void TextInput::Create(wxWindow *     parent,
     state_handler.attach({&label_color, & text_color});
     state_handler.update_binds();
     text_ctrl = new TextCtrl(this, wxID_ANY, text, {4, 4}, wxDefaultSize, style | wxBORDER_NONE | wxTE_PROCESS_ENTER);
+
+#ifdef __WXGTK__
+    Slic3r::GUI::RemoveInputBorder(text_ctrl);
+#endif
+
     text_ctrl->SetFont(Label::Body_14);
     text_ctrl->SetInitialSize(text_ctrl->GetBestSize());
     text_ctrl->SetBackgroundColour(background_color.colorForStates(state_handler.states()));

src/slic3r/GUI/wxExtensions.cpp

@@ -1022,6 +1022,10 @@ ScalableButton::ScalableButton( wxWindow *          parent,
         m_width = size.x * 10 / em;
         m_height= size.y * 10 / em;
     }
+
+#ifdef __WXGTK__
+    Slic3r::GUI::RemoveButtonBorder(this);
+#endif
 }