Small fixes for DGL, add Cairo widget class

source/modules/distrho/dgl/CairoWidget.hpp

@@ -0,0 +1,141 @@
+/*
+ * DISTRHO Plugin Toolkit (DPT)
+ * Copyright (C) 2012-2013 Filipe Coelho <falktx@falktx.com>
+ *
+ * Permission to use, copy, modify, and/or distribute this software for any purpose with
+ * or without fee is hereby granted, provided that the above copyright notice and this
+ * permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES WITH REGARD
+ * TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS. IN
+ * NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
+ * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER
+ * IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
+ * CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+#ifndef DGL_CAIRO_WIDGET_HPP_INCLUDED
+#define DGL_CAIRO_WIDGET_HPP_INCLUDED
+
+#include "Widget.hpp"
+
+#include <cairo.h>
+
+START_NAMESPACE_DGL
+
+// -----------------------------------------------------------------------
+
+class CairoWidget : public Widget
+{
+public:
+    CairoWidget(Window& parent)
+        : Widget(parent),
+          fContext(nullptr),
+          fSurface(nullptr),
+          fTextureId(0)
+    {
+    }
+
+protected:
+    virtual void cairoDisplay(cairo_t* const context) = 0;
+
+private:
+    void onReshape(int width, int height) override
+    {
+        // handle resize
+        Widget::onReshape(width, height);
+
+        // free previous if needed
+        onClose();
+
+        // create new
+        fSurface = cairo_image_surface_create(CAIRO_FORMAT_RGB24, width, height);
+        fContext = cairo_create(fSurface);
+
+        glGenTextures(1, &fTextureId);
+    }
+
+    void onClose() override
+    {
+        if (fContext != nullptr)
+        {
+            cairo_destroy(fContext);
+            fContext = nullptr;
+        }
+
+        if (fSurface != nullptr)
+        {
+            cairo_surface_destroy(fSurface);
+            fSurface = nullptr;
+        }
+
+        if (fTextureId != 0)
+        {
+            glDeleteTextures(1, &fTextureId);
+            fTextureId = 0;
+        }
+    }
+
+    void onDisplay() override
+    {
+        // wait for first resize
+        if (fSurface == nullptr || fContext == nullptr)
+        {
+            glClear(GL_COLOR_BUFFER_BIT);
+            return;
+        }
+
+        const int width  = getWidth();
+        const int height = getHeight();
+
+        // draw cairo stuff
+        cairoDisplay(fContext);
+
+        // get cairo surface data (RGB24)
+        unsigned char* const surfaceData = cairo_image_surface_get_data(fSurface);
+
+        // enable GL texture
+        glEnable(GL_TEXTURE_RECTANGLE_ARB);
+
+        // set texture params
+        glTexEnvi(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_MODULATE);
+        glTexParameteri(GL_TEXTURE_RECTANGLE_ARB, GL_TEXTURE_MIN_FILTER, GL_LINEAR_MIPMAP_LINEAR);
+        glTexParameteri(GL_TEXTURE_RECTANGLE_ARB, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
+
+        // bind texture to surface data
+        glBindTexture(GL_TEXTURE_RECTANGLE_ARB, fTextureId);
+        glTexImage2D(GL_TEXTURE_RECTANGLE_ARB, 0, GL_RGBA, width, height, 0, GL_BGRA, GL_UNSIGNED_BYTE, surfaceData);
+
+        // draw the texture
+        glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
+
+        glBegin(GL_QUADS);
+          glTexCoord2i(0, height);
+          glVertex2i(0, height);
+
+          glTexCoord2i(width, height);
+          glVertex2i(width, height);
+
+          glTexCoord2i(width, 0);
+          glVertex2i(width, 0);
+
+          glTexCoord2i(0, 0);
+          glVertex2i(0, 0);
+        glEnd();
+
+        // cleanup
+        glBindTexture(GL_TEXTURE_RECTANGLE_ARB, 0);
+        glDisable(GL_TEXTURE_RECTANGLE_ARB);
+    }
+
+private:
+    cairo_t*         fContext;
+    cairo_surface_t* fSurface;
+    GLuint           fTextureId;
+};
+
+// -----------------------------------------------------------------------
+
+END_NAMESPACE_DGL
+
+#endif // DGL_CAIRO_WIDGET_HPP_INCLUDED

source/modules/distrho/dgl/StandaloneWindow.hpp

@@ -18,7 +18,6 @@
 #define DGL_STANDALONE_WINDOW_HPP_INCLUDED
 
 #include "App.hpp"
-#include "Widget.hpp"
 #include "Window.hpp"
 
 START_NAMESPACE_DGL
@@ -30,16 +29,16 @@ class StandaloneWindow
 public:
     StandaloneWindow()
         : fApp(),
-          fWindow(&fApp)
+          fWindow(fApp)
     {
     }
 
-    App& getApp() const noexcept
+    App& getApp() noexcept
     {
         return fApp;
     }
 
-    Window& getWindow() const noexcept
+    Window& getWindow() noexcept
     {
         return fWindow;
     }

source/modules/distrho/dgl/Widget.hpp

@@ -76,7 +76,7 @@ public:
     void repaint();
 
 protected:
-    virtual void onDisplay();
+    virtual void onDisplay() = 0;
     virtual bool onKeyboard(bool press, uint32_t key);
     virtual bool onMouse(int button, bool press, int x, int y);
     virtual bool onMotion(int x, int y);

source/modules/distrho/dgl/src/ImageKnob.cpp

@@ -209,7 +209,7 @@ void ImageKnob::onDisplay()
         const GLint w2 = getWidth()/2;
         const GLint h2 = getHeight()/2;
 
-        glTranslatef(getX()+w2, getY()+h2, 0.f);
+        glTranslatef(getX()+w2, getY()+h2, 0.0f);
         glRotatef(normValue*fRotationAngle, 0.0f, 0.0f, 1.0f);
 
         glBegin(GL_QUADS);

source/modules/distrho/dgl/src/Widget.cpp

@@ -197,10 +197,6 @@ void Widget::repaint()
     fParent.repaint();
 }
 
-void Widget::onDisplay()
-{
-}
-
 bool Widget::onKeyboard(bool, uint32_t)
 {
     return false;

source/modules/distrho/dgl/src/Window.cpp

@@ -554,6 +554,7 @@ protected:
         FOR_EACH_WIDGET(it)
         {
             Widget* const widget(*it);
+            widget->fArea.setSize(width, height);
             widget->onReshape(width, height);
         }
     }