Porting focus based features and fix rendering

src/platform/render_opengl.cpp

@@ -76,7 +76,7 @@ void EndFrameRender(Color color) {
         GLint   y    = (GLint)rect.min.y;
         GLsizei w    = (GLsizei)(rect.max.x - rect.min.x);
         GLsizei h    = (GLsizei)(rect.max.y - rect.min.y);
-        glScissor(x, (GLint)WindowSize.y - h, w, h);
+        glScissor(x, (GLint)WindowSize.y - (GLint)rect.max.y, w, h);
         glNamedBufferSubData(VBO, 0, it->count * sizeof(Vertex2D), it->vertices);
         glBindVertexArray(VAO);
         GLint s_texture = 0; // texture unit that sampler2D will use in GLSL code
@@ -229,6 +229,8 @@ void SetScissor(Rect2 rect) {
     }
 }
 
+void SetScissor(Rect2I rect) { SetScissor(ToRect2(rect)); }
+
 Vertex2D *AllocVertex2D(Allocator allocator, VertexList2D *list, int count) {
     VertexNode2D *node = list->last;
     if (node == 0 || node->count + count > Lengthof(node->vertices)) {
@@ -293,6 +295,9 @@ void PushQuad2D(Allocator arena, VertexList2D *list, Rect2 rect, Rect2 tex, Colo
 void DrawRect(Rect2 rect, Color color) {
     PushQuad2D(RenderArena, &Vertices, rect, MainFont.white_texture_bounding_box, color);
 }
+void DrawRect(Rect2I rect, Color color) {
+    PushQuad2D(RenderArena, &Vertices, ToRect2(rect), MainFont.white_texture_bounding_box, color);
+}
 
 Vec2 DrawString(Font *font, String16 string, Vec2 pos, Color color, bool draw = true) {
     pos.y += font->ascent - font->descent;
@@ -309,6 +314,38 @@ Vec2 DrawString(Font *font, String16 string, Vec2 pos, Color color, bool draw =
     return result;
 }
 
+#define PI32 3.14159265359f
+void DrawCircle(Vec2 pos, float radius, Color color) {
+    const int segment_count = 16;
+    const int vertex_count  = segment_count * 3;
+    Vec2      points[segment_count + 1];
+    for (int i = 0; i < Lengthof(points); i += 1) {
+        float radians = 2.0f * PI32 * float(i) / float(segment_count);
+        float x       = radius * cosf(radians);
+        float y       = radius * sinf(radians);
+        points[i]     = {x, y};
+    }
+    points[segment_count] = points[0]; // wrap around
+
+    Vertex2D *vertices  = AllocVertex2D(RenderArena, &Vertices, vertex_count);
+    int       point_i   = 0;
+    int       segment_i = 0;
+    for (; segment_i < vertex_count; segment_i += 3, point_i += 1) {
+        Rect2     tex = MainFont.white_texture_bounding_box;
+        Vertex2D *it  = vertices + segment_i;
+        it[0].color   = color;
+        it[1].color   = color;
+        it[2].color   = color;
+        it[0].tex     = {tex.min.x, tex.max.y};
+        it[1].tex     = {tex.max.x, tex.max.y};
+        it[2].tex     = {tex.min.x, tex.min.y};
+
+        it[0].pos = {pos + points[point_i]};
+        it[1].pos = {pos + points[point_i + 1]};
+        it[2].pos = {pos};
+    }
+}
+
 Vec2 GetStringSize(Font *font, String16 string) {
     return DrawString(font, string, {}, {}, false);
 }