pen state and buttons color when active

engine/canvas.cpp

@@ -88,7 +88,7 @@ void ui::Canvas::stroke_draw()
         else
         {
             glDisable(GL_BLEND);
-            if (m_erase)
+            if (m_state == kPenState::Erase)
             {
                 ShaderManager::use(ui::kShader::StrokeErase);
                 //ShaderManager::u_vec4(kShaderUniform::Col, m_brush.m_tip_color);
@@ -275,7 +275,7 @@ void ui::Canvas::stroke_commit()
         m_tex2[i].bind();
         m_sampler.bind(0);
         m_sampler_bg.bind(1);
-        if (m_erase)
+        if (m_state == kPenState::Erase)
         {
             ShaderManager::use(ui::kShader::Texture);
         }
@@ -324,7 +324,7 @@ void ui::Canvas::stroke_start(glm::vec2 point, float pressure, const ui::Brush&
         m_dirty_box[i] = glm::vec4(m_width, m_height, 0, 0); // reset bounding box
         m_dirty_face[i] = false;
         
-        if (m_erase)
+        if (m_state == kPenState::Erase)
         {
             m_layers[m_current_layer_idx].m_rtt[i].bindFramebuffer();
             m_tmp[i].bindTexture();