commit 17898831bcee45d4615b5b7b55711c36ccd0f82e
author Jesse Barker <jesse.barker@linaro.org> Thu Jul 26 09:07:43 2012 -0700
committer Jesse Barker <jesse.barker@linaro.org> Thu Jul 26 09:07:43 2012 -0700
tree ef164c477da8d6686ecd8163d62c7318a6084c66
parent 311cbb81b51938ec4fb42eeeb11aca6459016ee5

SceneJellyfish: Save and restore custom GL state so other scenes are unaffected
when "reuse-context" is enabled.

src/scene-jellyfish.cpp

diff --git a/src/scene-jellyfish.cpp b/src/scene-jellyfish.cpp
index 59fdf41..5253dd9 100644
--- a/src/scene-jellyfish.cpp
+++ b/src/scene-jellyfish.cpp
@@ -348,7 +348,12 @@
     fresnelPower_(1.0),
     rotation_(0.0),
     currentTime_(0.0),
-    lastUpdateTime_(0.0)
+    lastUpdateTime_(0.0),
+    cullFace_(0),
+    depthTest_(0),
+    blend_(0),
+    blendFuncSrc_(0),
+    blendFuncDst_(0)
 {
     static const string modelFilename(GLMARK_DATA_PATH"/models/jellyfish.jobj");
     if (!load_obj(modelFilename))
@@ -467,6 +472,18 @@
         glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);
         glBindTexture(GL_TEXTURE_2D, 0);
     }
+
+    // Save the GL state we are changing so we can restore it later.
+    cullFace_ = glIsEnabled(GL_CULL_FACE);
+    depthTest_ = glIsEnabled(GL_DEPTH_TEST);
+    blend_ = glIsEnabled(GL_BLEND);
+    glGetIntegerv(GL_BLEND_SRC_RGB, &blendFuncSrc_);
+    glGetIntegerv(GL_BLEND_DST_RGB, &blendFuncDst_);
+
+    glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
+    glEnable(GL_BLEND);
+    glDisable(GL_CULL_FACE);
+    glDisable(GL_DEPTH_TEST);
 }
 
 void
@@ -495,6 +512,21 @@
 void
 JellyfishPrivate::cleanup()
 {
+    // Restore the GL state we changed for the scene.
+    glBlendFunc(blendFuncSrc_, blendFuncDst_);
+    if (GL_FALSE == blend_)
+    {
+        glDisable(GL_BLEND);
+    }
+    if (GL_TRUE == cullFace_)
+    {
+        glEnable(GL_CULL_FACE);
+    }
+    if (GL_TRUE == depthTest_)
+    {
+        glEnable(GL_DEPTH_TEST);
+    }
+
     program_.stop();
     program_.release();
 
@@ -554,12 +586,6 @@
     glBindTexture(GL_TEXTURE_2D, textureObjects_[whichCaustic_]);
     program_["uSampler1"] = 1;
 
-    glEnable(GL_BLEND);
-    glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
-
-    glDisable(GL_CULL_FACE);
-    glDisable(GL_DEPTH_TEST);
-
     glBindBuffer(GL_ARRAY_BUFFER, bufferObjects_[0]);
     glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, bufferObjects_[1]);
 

src/scene-jellyfish.h

diff --git a/src/scene-jellyfish.h b/src/scene-jellyfish.h
index 97dc5de..77be159 100644
--- a/src/scene-jellyfish.h
+++ b/src/scene-jellyfish.h
@@ -104,6 +104,12 @@
     float rotation_;
     float currentTime_;
     double lastUpdateTime_;
+    // GL state we plan to override, so we can restore it cleanly.
+    unsigned int cullFace_;
+    unsigned int depthTest_;
+    unsigned int blend_;
+    int blendFuncSrc_;
+    int blendFuncDst_;
 
 public:
     JellyfishPrivate();