OPENGL: Handle destruction gracefully when no context is setup.

4 files changed, 24 insertions, 5 deletions

diff --git a/backends/graphics/opengl/opengl-sys.h b/backends/graphics/opengl/opengl-sys.h
index f8acb9302c..dabd6adaa7 100644
--- a/backends/graphics/opengl/opengl-sys.h
+++ b/backends/graphics/opengl/opengl-sys.h
@@ -111,7 +111,13 @@ extern Context g_context;
 
 } // End of namespace OpenGL
 
-#define GL_CALL(x)        GL_WRAP_DEBUG(g_context.x, x)
-#define GL_ASSIGN(var, x) GL_WRAP_DEBUG(var = g_context.x, x)
+#define GL_CALL(x)                 GL_WRAP_DEBUG(g_context.x, x)
+#define GL_CALL_SAFE(func, params) \
+	do { \
+		if (g_context.func) { \
+			GL_CALL(func params); \
+		} \
+	} while (0)
+#define GL_ASSIGN(var, x)          GL_WRAP_DEBUG(var = g_context.x, x)
 
 #endif
diff --git a/backends/graphics/opengl/shader.cpp b/backends/graphics/opengl/shader.cpp
index c28036cb4e..d7fc20574b 100644
--- a/backends/graphics/opengl/shader.cpp
+++ b/backends/graphics/opengl/shader.cpp
@@ -74,6 +74,15 @@ ShaderARB::ShaderARB(const Common::String &vertex, const Common::String &fragmen
     : Shader(vertex, fragment), _program(0), _projectionLocation(-1), _textureLocation(-1) {
 }
 
+ShaderARB::~ShaderARB() {
+	// According to extension specification glDeleteObjectARB silently ignores
+	// 0. However, with nVidia drivers this can cause GL_INVALID_VALUE, thus
+	// we do not call it with 0 as parameter to avoid warnings.
+	if (_program) {
+		GL_CALL_SAFE(glDeleteObjectARB, (_program));
+	}
+}
+
 void ShaderARB::destroy() {
 	// According to extension specification glDeleteObjectARB silently ignores
 	// 0. However, with nVidia drivers this can cause GL_INVALID_VALUE, thus
@@ -200,6 +209,10 @@ ShaderGLES2::ShaderGLES2(const Common::String &vertex, const Common::String &fra
     : Shader(vertex, fragment), _program(0), _projectionLocation(-1), _textureLocation(-1) {
 }
 
+ShaderGLES2::~ShaderGLES2() {
+	GL_CALL_SAFE(glDeleteProgram, (_program));
+}
+
 void ShaderGLES2::destroy() {
 	GL_CALL(glDeleteProgram(_program));
 	_program = 0;
diff --git a/backends/graphics/opengl/shader.h b/backends/graphics/opengl/shader.h
index 8c457f8f91..60a430214c 100644
--- a/backends/graphics/opengl/shader.h
+++ b/backends/graphics/opengl/shader.h
@@ -88,7 +88,7 @@ protected:
 class ShaderARB : public Shader {
 public:
 	ShaderARB(const Common::String &vertex, const Common::String &fragment);
-	virtual ~ShaderARB() { destroy(); }
+	virtual ~ShaderARB();
 
 	virtual void destroy();
 
@@ -127,7 +127,7 @@ private:
 class ShaderGLES2 : public Shader {
 public:
 	ShaderGLES2(const Common::String &vertex, const Common::String &fragment);
-	virtual ~ShaderGLES2() { destroy(); }
+	virtual ~ShaderGLES2();
 
 	virtual void destroy();
 
diff --git a/backends/graphics/opengl/texture.cpp b/backends/graphics/opengl/texture.cpp
index 0b01430728..e394f760f9 100644
--- a/backends/graphics/opengl/texture.cpp
+++ b/backends/graphics/opengl/texture.cpp
@@ -54,7 +54,7 @@ Texture::Texture(GLenum glIntFormat, GLenum glFormat, GLenum glType, const Graph
 }
 
 Texture::~Texture() {
-	releaseInternalTexture();
+	GL_CALL_SAFE(glDeleteTextures, (1, &_glTexture));
 	_textureData.free();
 }