Minor modifications to shader and image activation

git-svn-id: https://sfml.svn.sourceforge.net/svnroot/sfml/branches/sfml2@1426 4e206d99-4929-0410-ac5d-dfc041789085

src/SFML/Graphics/Image.cpp

@@ -493,12 +493,8 @@ void Image::Bind() const
     EnsureTextureUpdate();
 
     // Bind it
-    if (myTexture)
-    {
-        GLCheck(glEnable(GL_TEXTURE_2D));
     GLCheck(glBindTexture(GL_TEXTURE_2D, myTexture));
 }
-}
 
 
 ////////////////////////////////////////////////////////////

src/SFML/Graphics/Renderer.cpp

@@ -58,6 +58,7 @@ void Renderer::Initialize()
     // Default render states
     GLCheck(glDisable(GL_LIGHTING));
     GLCheck(glDisable(GL_DEPTH_TEST));
+    GLCheck(glEnable(GL_TEXTURE_2D));
     GLCheck(glEnable(GL_ALPHA_TEST));
     GLCheck(glAlphaFunc(GL_GREATER, 0));
 
@@ -241,7 +242,7 @@ void Renderer::SetTexture(const Image* texture)
         if (texture)
             texture->Bind();
         else
-            GLCheck(glDisable(GL_TEXTURE_2D));
+            GLCheck(glBindTexture(GL_TEXTURE_2D, 0));
 
         // Store it
         myTexture = texture;
@@ -254,18 +255,21 @@ void Renderer::SetTexture(const Image* texture)
 void Renderer::SetShader(const Shader* shader)
 {
     if ((shader != myShader) || !myShaderIsValid)
+    {
+        if (Shader::IsAvailable()) // to avoid calling possibly unsupported functions
         {
             // Apply the new shader
             if (shader)
                 shader->Bind();
-        else if (myShaderIsValid && myShader)
+            else
-            myShader->Unbind();
+                GLCheck(glUseProgramObjectARB(0));
 
             // Store it
             myShader = shader;
             myShaderIsValid = true;
         }
     }
+}
 
 
 ////////////////////////////////////////////////////////////

src/SFML/Graphics/Shader.cpp

@@ -45,8 +45,7 @@ Shader::Shader() :
 myShaderProgram (0),
 myCurrentTexture(-1)
 {
-    // Make sure that GLEW is initialized
+
-    priv::EnsureGlewInit();
 }
 
 
@@ -208,6 +207,8 @@ void Shader::SetParameter(const std::string& name, const Vector3f& v)
 
 ////////////////////////////////////////////////////////////
 void Shader::SetTexture(const std::string& name, const Image& texture)
+{
+    if (myShaderProgram)
     {
         // Check if there is a texture unit available
         GLint maxUnits;
@@ -232,15 +233,14 @@ void Shader::SetTexture(const std::string& name, const Image& texture)
         else
             myCurrentTexture = location;
     }
+}
 
 
 ////////////////////////////////////////////////////////////
 void Shader::Bind() const
 {
-    // Make sure that we have a valid program
+    if (myShaderProgram)
-    if (!myShaderProgram)
+    {
-        return;
-
         // Enable the program
         GLCheck(glUseProgramObjectARB(myShaderProgram));
 
@@ -262,29 +262,13 @@ void Shader::Bind() const
         if (myCurrentTexture != -1)
             GLCheck(glUniform1iARB(myCurrentTexture, 0));
     }
+}
 
 
 ////////////////////////////////////////////////////////////
 void Shader::Unbind() const
 {
-    // First make sure that the program is currently bound
-    GLhandleARB program = glGetHandleARB(GL_PROGRAM_OBJECT_ARB);
-    if (!myShaderProgram || (myShaderProgram != program))
-        return;
-
-    // Unbind the program
     GLCheck(glUseProgramObjectARB(0));
-
-    // Disable texture units
-    for (std::size_t i = 0; i < myTextures.size(); ++i)
-    {
-        GLint index = static_cast<GLsizei>(i + 1);
-        GLCheck(glActiveTextureARB(GL_TEXTURE0_ARB + index));
-        GLCheck(glBindTexture(GL_TEXTURE_2D, 0));
-    }
-
-    // Make sure that the texture unit which is left active is the number 0
-    GLCheck(glActiveTextureARB(GL_TEXTURE0_ARB));
 }
 
 
@@ -326,6 +310,9 @@ bool Shader::CompileProgram()
         return false;
     }
 
+    // Make sure that GLEW is initialized (extra safety -- it is already done in IsAvailable())
+    priv::EnsureGlewInit();
+
     // Destroy the shader if it was already created
     if (myShaderProgram)
         GLCheck(glDeleteObjectARB(myShaderProgram));