lovr.graphics.circle;

src/api/graphics.c

@@ -525,6 +525,15 @@ int l_lovrGraphicsBox(lua_State* L) {
   return luax_rectangularprism(L, false);
 }
 
+int l_lovrGraphicsCircle(lua_State* L) {
+  DrawMode drawMode = *(DrawMode*) luax_checkenum(L, 1, &DrawModes, "draw mode");
+  float transform[16];
+  int index = luax_readtransform(L, 2, transform, true);
+  int segments = luaL_optnumber(L, index, 32);
+  lovrGraphicsCircle(drawMode, transform, segments);
+  return 0;
+}
+
 int l_lovrGraphicsCylinder(lua_State* L) {
   float x1 = luaL_checknumber(L, 1);
   float y1 = luaL_checknumber(L, 2);
@@ -815,6 +824,7 @@ const luaL_Reg lovrGraphics[] = {
   { "plane", l_lovrGraphicsPlane },
   { "cube", l_lovrGraphicsCube },
   { "box", l_lovrGraphicsBox },
+  { "circle", l_lovrGraphicsCircle },
   { "cylinder", l_lovrGraphicsCylinder },
   { "sphere", l_lovrGraphicsSphere },
   { "skybox", l_lovrGraphicsSkybox },

src/graphics/graphics.c

@@ -707,6 +707,48 @@ void lovrGraphicsBox(DrawMode mode, mat4 transform) {
   lovrGraphicsPop();
 }
 
+void lovrGraphicsCircle(DrawMode mode, mat4 transform, int segments) {
+  lovrGraphicsPush();
+  lovrGraphicsMatrixTransform(MATRIX_MODEL, transform);
+
+  vec_clear(&state.streamData);
+
+  if (mode == DRAW_MODE_LINE) {
+  } else if (mode == DRAW_MODE_FILL) {
+    vec_push(&state.streamData, 0);
+    vec_push(&state.streamData, 0);
+    vec_push(&state.streamData, 0);
+
+    vec_push(&state.streamData, 0);
+    vec_push(&state.streamData, 0);
+    vec_push(&state.streamData, 1);
+
+    vec_push(&state.streamData, .5);
+    vec_push(&state.streamData, .5);
+
+    for (int i = 0; i <= segments; i++) {
+      float theta = i / (float) segments * 2 * M_PI;
+      float x = cos(theta) * .5;
+      float y = sin(theta) * .5;
+      vec_push(&state.streamData, x);
+      vec_push(&state.streamData, y);
+      vec_push(&state.streamData, 0);
+
+      vec_push(&state.streamData, 0);
+      vec_push(&state.streamData, 0);
+      vec_push(&state.streamData, 1);
+
+      vec_push(&state.streamData, x + .5);
+      vec_push(&state.streamData, 1 - (y + .5));
+    }
+
+    lovrGraphicsSetDefaultShader(SHADER_DEFAULT);
+    lovrGraphicsDrawPrimitive(GL_TRIANGLE_FAN, true, true, false);
+  }
+
+  lovrGraphicsPop();
+}
+
 void lovrGraphicsCylinder(float x1, float y1, float z1, float x2, float y2, float z2, float r1, float r2, bool capped, int segments) {
   float axis[3] = { x1 - x2, y1 - y2, z1 - z2 };
   float n[3] = { x1 - x2, y1 - y2, z1 - z2 };

src/graphics/graphics.h

@@ -163,6 +163,7 @@ void lovrGraphicsTriangle(DrawMode mode, float* points);
 void lovrGraphicsPlane(DrawMode mode, mat4 transform);
 void lovrGraphicsPlaneFullscreen(Texture* texture);
 void lovrGraphicsBox(DrawMode mode, mat4 transform);
+void lovrGraphicsCircle(DrawMode mode, mat4 transform, int segments);
 void lovrGraphicsCylinder(float x1, float y1, float z1, float x2, float y2, float z2, float r1, float r2, bool capped, int segments);
 void lovrGraphicsSphere(mat4 transform, int segments);
 void lovrGraphicsSkybox(Texture* texture, float angle, float ax, float ay, float az);