diff --git a/PanoPainter/GameViewController.m b/PanoPainter/GameViewController.m
index d969d94..9c2ba66 100644
--- a/PanoPainter/GameViewController.m
+++ b/PanoPainter/GameViewController.m
@@ -200,9 +200,9 @@ std::set<UITouch*> ignored_touch;
     if (source == kEventSource::Stylus)
         pen_down = true;
     
-    if (touch.majorRadius > 25.f)
-        ignored_touch.insert(touch);
-    NSLog(@"touch down size %f", touch.majorRadius);
+//    if (touch.majorRadius > 25.f)
+//        ignored_touch.insert(touch);
+//    NSLog(@"touch down size %f", touch.majorRadius);
     [self async_lock];
     App::I.mouse_down(0, touchLocation.x * scale, touchLocation.y * scale, touch.force, source);
     [self async_unlock];
diff --git a/engine/app.cpp b/engine/app.cpp
index 158d83c..f01802e 100644
--- a/engine/app.cpp
+++ b/engine/app.cpp
@@ -42,7 +42,7 @@ bool App::request_close()
         m->m_title->set_text("Unsaved document");
         m->m_message->set_text("Do you want to close without saving?");
         m->btn_ok->m_text->set_text("Yes");
-        m->btn_ok->on_click = [](Node*) {
+        m->btn_ok->on_click = [this](Node*) {
 #ifdef _WIN32
             destroy_window();
             PostQuitMessage(0);
diff --git a/engine/canvas.cpp b/engine/canvas.cpp
index 6d6095e..7441c22 100644
--- a/engine/canvas.cpp
+++ b/engine/canvas.cpp
@@ -223,6 +223,7 @@ void ui::Canvas::stroke_draw_mix(const glm::vec2& bb_min, const glm::vec2& bb_sz
 {
     m_mixer.bindFramebuffer();
 
+    float zoom = m_node->root()->m_zoom;
     glViewport(0, 0, m_mixer.getWidth(), m_mixer.getHeight());
     glDisable(GL_DEPTH_TEST);
     glEnable(GL_SCISSOR_TEST);
@@ -325,6 +326,8 @@ void ui::Canvas::stroke_draw()
     GLfloat cc[4];
     glGetIntegerv(GL_VIEWPORT, vp);
     glGetFloatv(GL_COLOR_CLEAR_VALUE, cc);
+    
+    float zoom = m_node->root()->m_zoom;
 
     auto m_brush = m_current_stroke->m_brush;
     auto samples = m_current_stroke->compute_samples();
@@ -354,9 +357,8 @@ void ui::Canvas::stroke_draw()
             glm::vec2 bb_max(0, 0);
             for (int j = 0; j < 4; j++)
             {
-                auto p = (m_mixer_sample.pos + off[j] + glm::vec2(0, 1));
+                auto p = (m_mixer_sample.pos + off[j]  * glm::orientate2(-s.angle) + glm::vec2(0, 1)) / zoom;
                 UV2[j] = p / sz;
-                //UV2[j].y = 1.f - UV2[j].y;
                 bb_min = glm::max({ 0, 0 }, glm::min(bb_min, p));
                 bb_max = glm::min(sz, glm::max(bb_max, p));
             }
@@ -897,8 +899,8 @@ void ui::Canvas::resize(int width, int height)
     for (int i = 0; i < 6; i++)
     {
 #if __IOS__
-        m_tmp[i].create(width, height, -1, GL_RGBA8);
-        m_tex[i].create(width, height, GL_RGBA8);
+        m_tmp[i].create(width, height, -1, GL_RGBA16F);
+        m_tex[i].create(width, height, GL_RGBA16F);
 #else
         m_tmp[i].create(width, height, -1, GL_RGBA32F);
         m_tex[i].create(width, height, GL_RGBA32F);
@@ -917,8 +919,8 @@ bool ui::Canvas::create(int width, int height)
     for (int i = 0; i < 6; i++)
     {
 #if __IOS__
-        m_tmp[i].create(width, height, -1, GL_RGBA8);
-        m_tex[i].create(width, height, GL_RGBA8);
+        m_tmp[i].create(width, height, -1, GL_RGBA16F);
+        m_tex[i].create(width, height, GL_RGBA16F);
 #else
         m_tmp[i].create(width, height, -1, GL_RGBA32F);
         m_tex[i].create(width, height, GL_RGBA32F);
diff --git a/engine/node_canvas.cpp b/engine/node_canvas.cpp
index 39ad660..9108e5e 100644
--- a/engine/node_canvas.cpp
+++ b/engine/node_canvas.cpp
@@ -280,8 +280,13 @@ void NodeCanvas::handle_resize(glm::vec2 old_size, glm::vec2 new_size)
 {
     if (new_size.x > m_canvas->m_width)
     {
-        m_canvas->m_mixer.create((int)new_size.x * m_canvas->m_mixer_scale, 
+#if __IOS__
+        m_canvas->m_mixer.create((int)new_size.x * m_canvas->m_mixer_scale,
+            (int)new_size.y * m_canvas->m_mixer_scale, -1, GL_RGBA16F);
+#else
+        m_canvas->m_mixer.create((int)new_size.x * m_canvas->m_mixer_scale,
             (int)new_size.y * m_canvas->m_mixer_scale, -1, GL_RGBA32F);
+#endif
         if (auto img = root()->find<NodeImageTexture>("tex-debug"))
             img->tex.assign(m_canvas->m_mixer.getTextureID());
         //             m_canvas->resize((int)new_size.x, (int)new_size.y);
diff --git a/engine/rtt.cpp b/engine/rtt.cpp
index c53e807..0acac00 100644
--- a/engine/rtt.cpp
+++ b/engine/rtt.cpp
@@ -58,10 +58,13 @@ bool RTT::create(int width, int height, int tex/* = -1*/, GLint internal_format)
         texID = tex;
     }
 
+    auto ifmt = GL_UNSIGNED_BYTE;
+    if (internal_format == GL_RGBA32F) ifmt = GL_FLOAT;
+    if (internal_format == GL_RGBA16F) ifmt = GL_HALF_FLOAT;
+    
     glBindTexture(GL_TEXTURE_2D, texID);
     if (tex == -1)
-        glTexImage2D(GL_TEXTURE_2D, 0, internal_format, width, height, 0, GL_RGBA,
-                     internal_format == GL_RGBA32F ? GL_FLOAT : GL_UNSIGNED_BYTE, 0);
+        glTexImage2D(GL_TEXTURE_2D, 0, internal_format, width, height, 0, GL_RGBA, ifmt, 0);
     glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
     glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
     glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
diff --git a/engine/texture.cpp b/engine/texture.cpp
index 031fbe2..312282c 100644
--- a/engine/texture.cpp
+++ b/engine/texture.cpp
@@ -46,8 +46,10 @@ bool Texture2D::create(int width, int height, GLint internal_format, GLint forma
     glGenTextures(1, &m_tex);
     //LOG("TEX create %d", m_tex);
     bind();
-    glTexImage2D(GL_TEXTURE_2D, 0, internal_format, width, height, 0, format,
-                 internal_format == GL_RGBA32F ? GL_FLOAT : GL_UNSIGNED_BYTE, data);
+    auto ifmt = GL_UNSIGNED_BYTE;
+    if (internal_format == GL_RGBA32F) ifmt = GL_FLOAT;
+    if (internal_format == GL_RGBA16F) ifmt = GL_HALF_FLOAT;
+    glTexImage2D(GL_TEXTURE_2D, 0, internal_format, width, height, 0, format, ifmt, data);
     unbind();
     return true;
 }