ClippingNode: cannot handle DrawNode::drawDot => DrawNode::drawSolidCircle works

[aismann]

Works not on Axmol 2.x and also not on Axmol 3
For retest: ClippingNodeTest.cpp changes:
Replace on ClippingNodeTest.cpp methods:
DrawNode* BasicTest::shape() and Sprite* BasicTest::grossini() with this lines:

DrawNode* BasicTest::shape()
{

    auto shape = DrawNode::create();
    static Vec2 triangle[3];
    triangle[0] = Vec2(-100, -100);
    triangle[1] = Vec2(100, -100);
    triangle[2] = Vec2(0, 100);

    static Color4F green(0, 1, 0, 1);
    // shape->drawPolygon(triangle, 3, green, 0, green);

    if (1) // set 0 if you want see the working drawSolidCircle
    {
        // always a retagle (should be a "circle")
        shape->drawDot(Vec2(50, 50), 40, green);
    }
    else //works
    {
        shape->drawSolidCircle(Vec2(50, 50), 40, 0, 48, green);
    }
    //Control shapes (show the look =>always circles)
    auto shapeControl = DrawNode::create();
    shapeControl->drawDot(Vec2(50, 50), 40, green);
    shapeControl->drawSolidCircle(Vec2(50, 250), 40, 0,48,green);
    addChild(shapeControl);

    return shape;
}

Sprite* BasicTest::grossini()
{
    auto grossini = Sprite::create(s_pathGrossini);
    grossini->setScale(10.5);
    return grossini;
}

DrawNode::drawDot should be a circle like the green circle left bottom
=> but is a rectangle:

DrawNode::drawSolidCircle works: (looks like the green circle left top)

[halx99]

Windows ? ANGLE on D3D11 ?

[aismann]

Windows
renderer: ANGLE (Intel, Intel(R) UHD Graphics 630 Direct3D11 vs_5_0 ps_5_0, D3D11-31.0.101.2112)
axmol.version: axmol-2.10.0-ac3b4d3

I/[2025-12-11 12:57:26.026][PID:53dc][TID:6460]
{
axmol.build_type: DEBUG
axmol.testcpp.autorun: false
supports_OES_depth24: true
max_texture_size: 16384
axmol.texture.pvrv2_has_alpha_premultiplied: false
supports_BGRA8888: false
supports_ETC1: false
max_vertex_attributes: 16
supports_vertex_array_object: false
axmol.3d.animate_quality: 2
axmol.3d.max_spot_light_in_shader: 1
max_texture_units: 32
supports_discard_framebuffer: true
supports_S3TC: false
version: OpenGL ES 3.0.0 (ANGLE 2.1.21145 git hash: dfa3a3070f78)
axmol.3d.max_point_light_in_shader: 1
supports_OES_map_buffer: true
supports_OES_packed_depth_stencil: true
axmol.compiled_with_profiler: false
renderer: ANGLE (Intel, Intel(R) UHD Graphics 630 Direct3D11 vs_5_0 ps_5_0, D3D11-31.0.101.2112)
supports_ASTC: false
axmol.gl.projection: 3d
glsl: OpenGL ES GLSL ES 3.00 (ANGLE 2.1.21145 git hash: dfa3a3070f78)
max_samples_allowed: 0
axmol.version: axmol-2.10.0-ac3b4d3
supports_ETC2: true
vendor: Google Inc. (Intel)
axmol.texture.pixel_format_for_png: rgba8888
supports_NPOT: true
supports_ATITC: false
axmol.fps: 60
supports_PVRTC: false
axmol.compiled_with_gl_state_cache: true
axmol.3d.max_dir_light_in_shader: 1
axmol.simd: SSE41
axmol.display_fps: true
}

[halx99]

due to angle based on D3d11, so it's also not support control point size in shader, do you test axmol v3 vulkan?

[aismann]

due to angle based on D3d11, so it's also not support control point size in shader, do you test axmol v3 vulkan

Same on axmol v3 vulkan ( axmol.version: 3.0.0-d6d1e6f):

[aismann]

due to angle based on D3d11, so it's also not support control point size in shader, do you test axmol v3 vulkan?

But the green dots is drawning as a circle.
So it is not the "POINT" shader restiction (drawDot using triangle shader, not point shader part, in this case)

[halx99]

Here is a clear explanation of the behavior you’re seeing:

Although the dot is rendered as a circle, the underlying geometry is still just two triangles forming a rectangle. GPU clipping (scissor, stencil, depth clip, etc.) always operates on the actual geometry, not on the visual result produced by the fragment shader. So even if the fragment shader discards pixels outside the circle, the stencil buffer will still receive a rectangular mask.

This is a hardware‑level behavior across all major graphics APIs (D3D, Vulkan, Metal, OpenGL). Fragment‑level discard or alpha does not change the shape of the clip region. To create a true circular clip, you must explicitly draw a circular stencil mask (e.g., a triangle fan or a distance‑field quad) instead of relying on shader‑based masking.