Fix resize in modernopengl with own context in SDL1.2 build.

4 files changed, 28 insertions, 6 deletions

diff --git a/src/render/graphics.cpp b/src/render/graphics.cpp
index a9dc968db..4c5d1d282 100644
--- a/src/render/graphics.cpp
+++ b/src/render/graphics.cpp
@@ -504,6 +504,7 @@ bool Graphics::resizeScreen(const int width, const int height)
     // +++ need impliment resize in soft mode
 #endif  // USE_OPENGL
 
+    screenResized();
     beginDraw();
     return true;
 
@@ -527,6 +528,7 @@ bool Graphics::resizeScreen(const int width, const int height)
         }
     }
 
+    screenResized();
     beginDraw();
 
     return success;
diff --git a/src/render/graphics.h b/src/render/graphics.h
index e05f23a84..3a051ed55 100644
--- a/src/render/graphics.h
+++ b/src/render/graphics.h
@@ -167,6 +167,9 @@ class Graphics notfinal
          */
         virtual bool resizeScreen(const int width, const int height);
 
+        virtual void restoreContext()
+        { }
+
         /**
          * Draws a resclaled version of the image
          */
@@ -468,6 +471,9 @@ class Graphics notfinal
                                  uint32_t *const arr A_UNUSED)
         { }
 
+        virtual void screenResized()
+        { }
+
         int mWidth;
         int mHeight;
         int mActualWidth;
diff --git a/src/render/modernopenglgraphics.cpp b/src/render/modernopenglgraphics.cpp
index 1fadba3c4..eb245e0de 100644
--- a/src/render/modernopenglgraphics.cpp
+++ b/src/render/modernopenglgraphics.cpp
@@ -117,6 +117,11 @@ ModernOpenGLGraphics::ModernOpenGLGraphics() :
 ModernOpenGLGraphics::~ModernOpenGLGraphics()
 {
     deleteArraysInternal();
+    deleteGLObjects();
+}
+
+void ModernOpenGLGraphics::deleteGLObjects()
+{
     if (mProgram)
         mProgram->decRef();
     if (mVbo)
@@ -191,14 +196,18 @@ void ModernOpenGLGraphics::postInit()
 //    mglVertexAttribIPointer(mPosAttrib, 4, GL_INT, 4 * sizeof(GLint), 0);
     mAttributesCached = mVbo;
 
-    screenResized();
+    mglUniform2f(mScreenUniform,
+        static_cast<float>(mWidth) / 2.0f,
+        static_cast<float>(mHeight) / 2.0f);
 }
 
 void ModernOpenGLGraphics::screenResized()
 {
-    mglUniform2f(mScreenUniform,
-        static_cast<float>(mWidth) / 2.0f,
-        static_cast<float>(mHeight) / 2.0f);
+    deleteGLObjects();
+    mVboCached = 0U;
+    mEboCached = 0U;
+    mAttributesCached = 0U;
+    postInit();
 }
 
 void ModernOpenGLGraphics::deleteArrays()
@@ -1261,7 +1270,10 @@ void ModernOpenGLGraphics::clearScreen() const
 
 void ModernOpenGLGraphics::createGLContext()
 {
-    mGLContext = SDL::createGLContext(mWindow, 3, 3);
+    if (mGLContext)
+        SDL::makeCurrentContext(mGLContext);
+    else
+        mGLContext = SDL::createGLContext(mWindow, 3, 3);
 }
 
 void ModernOpenGLGraphics::finalize(ImageCollection *const col)
diff --git a/src/render/modernopenglgraphics.h b/src/render/modernopenglgraphics.h
index 2b27c621e..86e9f7bf1 100644
--- a/src/render/modernopenglgraphics.h
+++ b/src/render/modernopenglgraphics.h
@@ -64,7 +64,7 @@ class ModernOpenGLGraphics final : public Graphics
         void setColorAll(const Color &color,
                          const Color &color2) override final;
 
-        void screenResized();
+        void screenResized() override final;
 
         void finalize(ImageCollection *const col) override final;
 
@@ -85,6 +85,8 @@ class ModernOpenGLGraphics final : public Graphics
         virtual void createGLContext() override final;
 
     private:
+        void deleteGLObjects();
+
         inline void drawQuad(const Image *const image,
                              const int srcX, const int srcY,
                              const int dstX, const int dstY,