From ca92d8c90f7103db6d7cae4cef49b278d804b474 Mon Sep 17 00:00:00 2001
From: dec05eba <dec05eba@protonmail.com>
Date: Wed, 20 Dec 2017 20:55:05 +0100
Subject: Create shader using c++ code

---
 include/RenderBackend/OpenGL/VertexShader.hpp | 70 +++++++++++++++++++++++++++
 1 file changed, 70 insertions(+)
 create mode 100644 include/RenderBackend/OpenGL/VertexShader.hpp

(limited to 'include/RenderBackend/OpenGL/VertexShader.hpp')

diff --git a/include/RenderBackend/OpenGL/VertexShader.hpp b/include/RenderBackend/OpenGL/VertexShader.hpp
new file mode 100644
index 0000000..ec8be22
--- /dev/null
+++ b/include/RenderBackend/OpenGL/VertexShader.hpp
@@ -0,0 +1,70 @@
+#pragma once
+
+#include "../../DataView.hpp"
+#include "ShaderVec.hpp"
+#include <string>
+#include <unordered_map>
+#include <vector>
+#include <stdexcept>
+#include <functional>
+
+namespace amalgine
+{
+    class VertexShaderTooManyAttributes : public std::runtime_error
+    {
+    public:
+        VertexShaderTooManyAttributes(i32 maxVertexAttributes);
+    };
+    
+    class VertexShaderAttributeAlreadyDefined : public std::runtime_error
+    {
+    public:
+        VertexShaderAttributeAlreadyDefined(const std::string &attributeName);
+    };
+    
+    class VertexShaderInvalidAttributeName : public std::runtime_error
+    {
+    public:
+        VertexShaderInvalidAttributeName(const std::string &attributeName);
+    };
+    
+    class VertexShaderFunctionAlreadyDefined : public std::runtime_error
+    {
+    public:
+        VertexShaderFunctionAlreadyDefined(const std::string &funcName);
+    };
+    
+    using VertexShaderMainFunc = std::function<ShaderVec4()>;
+    
+    /*
+     * Using the same VertexShader instance in multiple threads to define data is not thread safe.
+     * All get*** functions are thread safe.
+     */
+    class VertexShader
+    {
+    public:
+        VertexShader();
+        
+        const std::string& getInputAttributeName(i32 attributeIndex);
+        ShaderInputVec2 defineInputVec2(const std::string &name);
+        void defineMain(VertexShaderMainFunc mainFunc);
+        std::string build();
+    private:
+        void writeHeader(const std::string &code);
+        void writeBody(const std::string &code);
+        
+        /*
+         * Throws VertexShaderTooManyInputAttributes if too many vertex attributes are defined for the platform.
+         * Throws VertexShaderAttributeAlreadyDefined if a vertex attribute with the same name has already been defined.
+         */
+        i32 defineInputVariable(const std::string &variableName, const char *typeName);
+    private:
+        std::string header;
+        std::string body;
+        int locationCounter;
+        i32 maxVertexAttribs; // Could make this static
+        std::unordered_map<std::string, i32> vertexAttributes;
+        std::vector<std::string> vertexAttributeNames;
+        bool mainFuncDefined;
+    };
+}
-- 
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