Adds point size support

include/flip/imdraw.h

@@ -28,9 +28,10 @@ struct ImMode {
 };
 
 struct ImVertex {
-  HMM_Vec3 position = {0, 0, 0};
-  Color color = {1, 1, 1, 1};
-  HMM_Vec2 uv = {0, 0};
+  HMM_Vec3 position = {0, 0, 0};  // Vertex position
+  Color color = {1, 1, 1, 1};     // Vertex color
+  HMM_Vec2 uv = {0, 0};           // Vertex texture coordinate
+  float size = 1.f;               // Point size primitive
 };
 
 // RAII to begin/end an immediate mode draw
@@ -57,6 +58,7 @@ class ImDraw {
   void color(float _r, float _g, float _b, float _a) {
     vertex_.color = {_r, _g, _b, _a};
   }
+  void size(float _size) { vertex_.size = _size; }
 
   // Modifies current (internal) vertex and submit point.
   void vertex(const HMM_Vec3& _xyz) {
@@ -74,13 +76,28 @@ class ImDraw {
     Submit();
   }
 
+  void vertex(const HMM_Vec3& _xyz, const Color& _color, float _size) {
+    vertex_.position = _xyz;
+    vertex_.color = _color;
+    vertex_.size = _size;
+    Submit();
+  }
+
   void vertex(float _x, float _y, float _z, float _r, float _g, float _b,
               float _a) {
     vertex_.position = {_x, _y, _z};
     vertex_.color = {_r, _g, _b, _a};
     Submit();
   }
 
+  void vertex(float _x, float _y, float _z, float _r, float _g, float _b,
+              float _a, float _size) {
+    vertex_.position = {_x, _y, _z};
+    vertex_.color = {_r, _g, _b, _a};
+    vertex_.size = _size;
+    Submit();
+  }
+
   void vertex(float _x, float _y, float _z, float _u, float _v) {
     vertex_.position = {_x, _y, _z};
     vertex_.uv = {_u, _v};
@@ -93,18 +110,18 @@ class ImDraw {
     Submit();
   }
 
-  void vertex(const HMM_Vec3& _xyz, const HMM_Vec2& _uv, const Color& _color) {
+  void vertex(const HMM_Vec3& _xyz, const Color& _color, const HMM_Vec2& _uv) {
     vertex_.position = _xyz;
-    vertex_.uv = _uv;
     vertex_.color = _color;
+    vertex_.uv = _uv;
     Submit();
   }
 
-  void vertex(float _x, float _y, float _z, float _u, float _v, float _r,
-              float _g, float _b, float _a) {
+  void vertex(float _x, float _y, float _z, float _r, float _g, float _b,
+              float _a, float _u, float _v) {
     vertex_.position = {_x, _y, _z};
-    vertex_.uv = {_u, _v};
     vertex_.color = {_r, _g, _b, _a};
+    vertex_.uv = {_u, _v};
     Submit();
   }
 

samples/imdraw/main.cpp

@@ -53,6 +53,18 @@ class ImDraw : public flip::Application {
       drawer.vertex(1, -1, 0);
     }
 
+    // Red axis points
+    {
+      auto drawer = flip::ImDraw{
+          _renderer, transform1_, {.type = SG_PRIMITIVETYPE_POINTS}};
+
+      drawer.color(flip::kRed);
+      drawer.size(10.f);
+
+      drawer.vertex(0, 1, 0);
+      drawer.vertex(0, -1, 0);
+    }
+
     return true;
   }
 

src/impl/imdrawer.cpp

@@ -17,10 +17,12 @@ ImDrawer::ImDrawer() {
       "layout(location=0) in vec3 position;\n"
       "layout(location=1) in vec4 color;\n"
       "layout(location=2) in vec2 uv;\n"
+      "layout(location=3) in float size;\n"
       "out vec2 vertex_uv;\n"
       "out vec4 vertex_color;\n"
       "void main() {\n"
       "  gl_Position = mvp * vec4(position, 1.);\n"
+      "  gl_PointSize = size;\n"
       "  vertex_uv = uv;\n"
       "  vertex_color = color;\n"
       "}\n";
@@ -75,10 +77,11 @@ void ImDrawer::Begin(const HMM_Mat4& _view_proj, const HMM_Mat4& _transform,
   if (it == pipelines_.end()) {
     sg_pipeline pip = sg_make_pipeline(sg_pipeline_desc{
         .shader = shaders_[_mode.alpha_test].id(),
-        .layout = {.buffers = {{.stride = 36}},
+        .layout = {.buffers = {{.stride = sizeof(ImVertex)}},
                    .attrs = {{.format = SG_VERTEXFORMAT_FLOAT3},
                              {.format = SG_VERTEXFORMAT_FLOAT4},
-                             {.format = SG_VERTEXFORMAT_FLOAT2}}},
+                             {.format = SG_VERTEXFORMAT_FLOAT2},
+                             {.format = SG_VERTEXFORMAT_FLOAT}}},
         .depth = {.compare = _mode.z_compare, .write_enabled = _mode.z_write},
         .colors = {{.blend = {.enabled = _mode.alpha_blending,
                               .src_factor_rgb = SG_BLENDFACTOR_SRC_ALPHA,
@@ -96,7 +99,7 @@ void ImDrawer::Begin(const HMM_Mat4& _view_proj, const HMM_Mat4& _transform,
   sg_apply_pipeline(it->second.id());
 
   const auto mvp = _view_proj * _transform;
-  sg_apply_uniforms(SG_SHADERSTAGE_VS, 0, {mvp.Elements[0], 64});
+  sg_apply_uniforms(SG_SHADERSTAGE_VS, 0, {mvp.Elements[0], sizeof(mvp)});
 }
 
 void ImDrawer::End(std::span<const ImVertex> _vertices, sg_image _image,