From fc5711f0db806b267c8b0aea4dfa7375480f5105 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Jaakko=20Kera=CC=88nen?= <jaakko.keranen@iki.fi>
Date: Wed, 21 Feb 2018 09:01:13 +0200
Subject: [PATCH] libgui|GL: More options for configuring a GLFramebuffer

---
 .../gui/include/de/graphics/glframebuffer.h   | 25 +++++++++++++------
 .../libs/gui/src/graphics/glframebuffer.cpp   | 17 ++++++++-----
 2 files changed, 29 insertions(+), 13 deletions(-)

diff --git a/doomsday/libs/gui/include/de/graphics/glframebuffer.h b/doomsday/libs/gui/include/de/graphics/glframebuffer.h
index 133a52c806..b836e3bf23 100644
--- a/doomsday/libs/gui/include/de/graphics/glframebuffer.h
+++ b/doomsday/libs/gui/include/de/graphics/glframebuffer.h
@@ -141,22 +141,33 @@ class LIBGUI_PUBLIC GLFramebuffer : public Asset
      * values and one for depth/stencil values.
      *
      * If @a colorTex or @a depthStencilTex is omitted, a renderbuffer will be
-     * created in its place.
+     * created in its place (depending on @a missingRenderBuffers).
      *
      * Any previous attachments are released.
      *
-     * @param colorTex         Texture for color values.
-     * @param depthStencilTex  Texture for depth/stencil values.
+     * @param colorTex              Texture for color values.
+     * @param depthStencilTex       Texture for depth/stencil values.
+     * @param missingRenderBuffers  Create renderbuffers for attachments where
+     *                              texture has not been specified.
      */
-    void configure(GLTexture *colorTex, GLTexture *depthStencilTex);
+    void configure(GLTexture *colorTex,
+                   GLTexture *depthStencilTex,
+                   Flags      missingRenderBuffers = ColorDepthStencil);
 
     /**
      * Reconfigures the framebuffer with multiple textures.
      *
-     * @param colorTextures    Textures for color attachments.
-     * @param depthStencilTex  Texture for depth/stencil values.
+     * If @a colorTex or @a depthStencilTex is omitted, a renderbuffer will be
+     * created in its place (depending on @a missingRenderBuffers).
+     *
+     * @param colorTextures         Textures for color attachments.
+     * @param depthStencilTex       Texture for depth/stencil values.
+     * @param missingRenderBuffers  Create renderbuffers for attachments where
+     *                              texture has not been specified.
      */
-    void configure(QList<GLTexture *> colorTextures, GLTexture *depthStencilTex);
+    void configure(QList<GLTexture *> colorTextures,
+                   GLTexture *        depthStencilTex,
+                   Flags              missingRenderBuffers = ColorDepthStencil);
 
     /**
      * Changes the configuration of the render target. Any previously allocated
diff --git a/doomsday/libs/gui/src/graphics/glframebuffer.cpp b/doomsday/libs/gui/src/graphics/glframebuffer.cpp
index 7b1d985c02..8affbd39cd 100644
--- a/doomsday/libs/gui/src/graphics/glframebuffer.cpp
+++ b/doomsday/libs/gui/src/graphics/glframebuffer.cpp
@@ -553,12 +553,16 @@ void GLFramebuffer::configure(Vec2ui const &size, Flags flags, int sampleCount)
     LIBGUI_ASSERT_GL_OK();
 }
 
-void GLFramebuffer::configure(GLTexture *colorTex, GLTexture *depthStencilTex)
+void GLFramebuffer::configure(GLTexture *colorTex,
+                              GLTexture *depthStencilTex,
+                              Flags      missingRenderBuffers)
 {
-    configure(QList<GLTexture *>({colorTex}), depthStencilTex);
+    configure(QList<GLTexture *>({colorTex}), depthStencilTex, missingRenderBuffers);
 }
 
-void GLFramebuffer::configure(QList<GLTexture *> colorTextures, GLTexture *depthStencilTex)
+void GLFramebuffer::configure(QList<GLTexture *> colorTextures,
+                              GLTexture *        depthStencilTex,
+                              Flags              missingRenderBuffers)
 {
     LOG_AS("GLFramebuffer");
 
@@ -588,7 +592,7 @@ void GLFramebuffer::configure(QList<GLTexture *> colorTextures, GLTexture *depth
         DENG2_ASSERT(d->size == colorTex->size());
         d->attachTexture(*colorTex, GL_COLOR_ATTACHMENT0 + i);
     }
-    if (colorTextures.isEmpty())
+    if (colorTextures.isEmpty() && missingRenderBuffers.testFlag(Color0))
     {
         d->attachRenderbuffer(Impl::ColorBuffer0, GL_RGBA8, GL_COLOR_ATTACHMENT0);
     }
@@ -600,9 +604,10 @@ void GLFramebuffer::configure(QList<GLTexture *> colorTextures, GLTexture *depth
         DENG2_ASSERT(d->size == depthStencilTex->size());
         d->attachTexture(*depthStencilTex, GL_DEPTH_STENCIL_ATTACHMENT);
     }
-    else
+    else if (missingRenderBuffers.testFlag(DepthStencil))
     {
-        d->attachRenderbuffer(Impl::DepthStencilBuffer, GL_DEPTH24_STENCIL8, GL_DEPTH_STENCIL_ATTACHMENT);
+        d->attachRenderbuffer(
+            Impl::DepthStencilBuffer, GL_DEPTH24_STENCIL8, GL_DEPTH_STENCIL_ATTACHMENT);
     }
 
     LIBGUI_ASSERT_GL_OK();