Add uniform (shader global variable)

1 files changed, 21 insertions, 0 deletions

diff --git a/src/RenderBackend/OpenGL/ShaderProgram.cpp b/src/RenderBackend/OpenGL/ShaderProgram.cpp
index 40f5b6c..aceda3b 100644
--- a/src/RenderBackend/OpenGL/ShaderProgram.cpp
+++ b/src/RenderBackend/OpenGL/ShaderProgram.cpp
@@ -12,6 +12,12 @@ namespace amalgine
         
     }
     
+    ShaderProgramNonExistingGlobalVariable::ShaderProgramNonExistingGlobalVariable(const char *variableName) : 
+        runtime_error(string("There is no shader global variable with the name '") + variableName + "'")
+    {
+        
+    }
+    
     ShaderProgram::ShaderProgram() : built(false)
     {
         shaderProgramId = glCreateProgram();
@@ -84,4 +90,19 @@ namespace amalgine
             throw ShaderProgramUsedBeforeBuilt();
         }
     }
+    
+    ShaderProgramGlobalVec3 ShaderProgram::getGlobalVec3(const char *name)
+    {
+        if(built)
+        {
+            GLint uniformId = glGetUniformLocation(shaderProgramId, name);
+            if(uniformId == -1)
+                throw ShaderProgramNonExistingGlobalVariable(name);
+            return ShaderProgramGlobalVec3(this, uniformId);
+        }
+        else
+        {
+            throw ShaderProgramUsedBeforeBuilt();
+        }
+    }
 }