LibGL: Implement glFlush() and glFinish()

Userland/Libraries/LibGL/GL/gl.h

@@ -124,6 +124,8 @@ void glCallList(GLuint list);
 void glDeleteLists(GLuint list, GLsizei range);
 void glEndList(void);
 void glNewList(GLuint list, GLenum mode);
+void glFlush();
+void glFinish();
 
 #ifdef __cplusplus
 }

Userland/Libraries/LibGL/GLContext.h

@@ -47,6 +47,8 @@ public:
     virtual void gl_delete_lists(GLuint list, GLsizei range) = 0;
     virtual void gl_end_list(void) = 0;
     virtual void gl_new_list(GLuint list, GLenum mode) = 0;
+    virtual void gl_flush() = 0;
+    virtual void gl_finish() = 0;
 
     virtual void present() = 0;
 };

Userland/Libraries/LibGL/GLUtils.cpp

@@ -59,3 +59,13 @@ GLenum glGetError()
 {
     return g_gl_context->gl_get_error();
 }
+
+void glFlush()
+{
+    return g_gl_context->gl_flush();
+}
+
+void glFinish()
+{
+    return g_gl_context->gl_finish();
+}

Userland/Libraries/LibGL/SoftwareGLContext.cpp

@@ -839,6 +839,26 @@ void SoftwareGLContext::gl_new_list(GLuint list, GLenum mode)
     m_current_listing_index = CurrentListing { {}, static_cast<size_t>(list - 1), mode };
 }
 
+void SoftwareGLContext::gl_flush()
+{
+    if (m_in_draw_state) {
+        m_error = GL_INVALID_OPERATION;
+        return;
+    }
+
+    // No-op since SoftwareGLContext is completely synchronous at the moment
+}
+
+void SoftwareGLContext::gl_finish()
+{
+    if (m_in_draw_state) {
+        m_error = GL_INVALID_OPERATION;
+        return;
+    }
+
+    // No-op since SoftwareGLContext is completely synchronous at the moment
+}
+
 void SoftwareGLContext::present()
 {
     m_rasterizer.blit_to(*m_frontbuffer);

Userland/Libraries/LibGL/SoftwareGLContext.h

@@ -53,6 +53,8 @@ public:
     virtual void gl_delete_lists(GLuint list, GLsizei range) override;
     virtual void gl_end_list(void) override;
     virtual void gl_new_list(GLuint list, GLenum mode) override;
+    virtual void gl_flush() override;
+    virtual void gl_finish() override;
 
     virtual void present() override;