Un-OOP the tutorial

Chapter1/2-HelloTriangle/Shaders/shader.vert

@@ -18,14 +18,14 @@
 //   shader(vertex)
 
 
-// This defines our input variable, aPosition.
+// This defines our input variable, aPos.
 // It starts with the line "layout(location = 0)". This defines where this input variable will be located, which is needed for GL.VertexAttribPointer.
-// However, you can omit it, and replace this with just "in vec3 aPosition". If you do that, you'll have to replace the 0 in GL.VertexAttribPointer with
+// However, you can omit it, and replace this with just "in vec3 aPos". If you do that, you'll have to replace the 0 in GL.VertexAttribPointer with
 //   a call to GL.GetAttribLocation(shaderHandle, attributeName)
 // Next, the keyword "in" defines this as an input variable. We'll have an example of the "out" keyword in the next tutorial.
 // Then, the keyword "vec3" means this is a vector with 3 floats inside.
 
-layout(location = 0) in vec3 aPosition;
+layout(location = 0) in vec3 aPos;
 
 
 // Like C, we have an entrypoint function. In this case, it takes void and returns void, and must be named main.
@@ -37,5 +37,5 @@ layout(location = 0) in vec3 aPosition;
 
 void main(void)
 {
-    gl_Position = vec4(aPosition, 1.0);
+    gl_Position = vec4(aPos, 1.0);
 }

Chapter1/2-HelloTriangle/Window.cs

@@ -114,11 +114,11 @@ protected override void OnLoad()
             // Shaders are tiny programs that live on the GPU. OpenGL uses them to handle the vertex-to-pixel pipeline.
             // Check out the Shader class in Common to see how we create our shaders, as well as a more in-depth explanation of how shaders work.
             // shader.vert and shader.frag contain the actual shader code.
-            _shader = new Shader("Shaders/shader.vert", "Shaders/shader.frag");
+            _shader = Shader.FromFile("Shaders/shader.vert", "Shaders/shader.frag");
 
             // Now, enable the shader.
             // Just like the VBO, this is global, so every function that uses a shader will modify this one until a new one is bound instead.
-            _shader.Use();
+            GL.UseProgram(_shader.Handle);
 
             // Setup is now complete! Now we move to the OnRenderFrame function to finally draw the triangle.
         }
@@ -140,7 +140,7 @@ protected override void OnRenderFrame(FrameEventArgs e)
             // and then calling an OpenGL function to render.
 
             // Bind the shader
-            _shader.Use();
+            GL.UseProgram(_shader.Handle);
 
             // Bind the VAO
             GL.BindVertexArray(_vertexArrayObject);

Chapter1/3-ElementBufferObjects/Shaders/shader.vert

@@ -1,8 +1,8 @@
 #version 330 core
 
-layout(location = 0) in vec3 aPosition;
+layout(location = 0) in vec3 aPos;
 
 void main(void)
 {
-    gl_Position = vec4(aPosition, 1.0);
+    gl_Position = vec4(aPos, 1.0);
 }

Chapter1/3-ElementBufferObjects/Window.cs

@@ -76,8 +76,8 @@ protected override void OnLoad()
             GL.BufferData(BufferTarget.ElementArrayBuffer, _indices.Length * sizeof(uint), _indices, BufferUsageHint.StaticDraw);
             // The EBO has now been properly setup. Go to the Render function to see how we draw our rectangle now!
 
-            _shader = new Shader("Shaders/shader.vert", "Shaders/shader.frag");
-            _shader.Use();
+            _shader = Shader.FromFile("Shaders/shader.vert", "Shaders/shader.frag");
+            GL.UseProgram(_shader.Handle);
         }
 
         protected override void OnRenderFrame(FrameEventArgs e)
@@ -86,7 +86,7 @@ protected override void OnRenderFrame(FrameEventArgs e)
 
             GL.Clear(ClearBufferMask.ColorBufferBit);
 
-            _shader.Use();
+            GL.UseProgram(_shader.Handle);
 
             // Because ElementArrayObject is a property of the currently bound VAO,
             // the buffer you will find in the ElementArrayBuffer will change with the currently bound VAO.

Chapter1/4-Shaders-InsAndOuts/Shaders/shader.vert

@@ -1,7 +1,7 @@
 #version 330 core
 
 // the position variable has attribute position 0
-layout(location = 0) in vec3 aPosition; 
+layout(location = 0) in vec3 aPos; 
 
 // This variable uses the keyword out in order to pass on the value to the 
 // next shader down in the chain, in this case the frag shader
@@ -10,7 +10,7 @@ out vec4 vertexColor;
 void main(void)
 {
 	// see how we directly give a vec3 to vec4's constructor
-    gl_Position = vec4(aPosition, 1.0);
+    gl_Position = vec4(aPos, 1.0);
 
 	// Here we assign the variable a dark red color to the out variable
 	vertexColor = vec4(0.5, 0.0, 0.0, 1.0);

Chapter1/4-Shaders-InsAndOuts/Window.cs

@@ -56,8 +56,9 @@ protected override void OnLoad()
             GL.GetInteger(GetPName.MaxVertexAttribs, out int maxAttributeCount);
             Debug.WriteLine($"Maximum number of vertex attributes supported: {maxAttributeCount}");
 
-            _shader = new Shader("Shaders/shader.vert", "Shaders/shader.frag");
-            _shader.Use();
+            _shader = Shader.FromFile("Shaders/shader.vert", "Shaders/shader.frag");
+
+            GL.UseProgram(_shader.Handle);
         }
 
         protected override void OnRenderFrame(FrameEventArgs e)
@@ -66,7 +67,7 @@ protected override void OnRenderFrame(FrameEventArgs e)
 
             GL.Clear(ClearBufferMask.ColorBufferBit);
 
-            _shader.Use();
+            GL.UseProgram(_shader.Handle);
 
             GL.BindVertexArray(_vertexArrayObject);
 

Chapter1/4-Shaders-MoreAttributes/Shaders/shader.vert

@@ -1,7 +1,7 @@
 #version 330 core
 
 // the position variable has attribute position 0
-layout(location = 0) in vec3 aPosition;  
+layout(location = 0) in vec3 aPos;
 
 // This is where the color values we assigned in the main program goes to
 layout(location = 1) in vec3 aColor;
@@ -11,7 +11,7 @@ out vec3 ourColor; // output a color to the fragment shader
 void main(void)
 {
 	// see how we directly give a vec3 to vec4's constructor
-    gl_Position = vec4(aPosition, 1.0); 
+    gl_Position = vec4(aPos, 1.0); 
 
 	// We use the outColor variable to pass on the color information to the frag shader
 	ourColor = aColor;

Chapter1/4-Shaders-MoreAttributes/Window.cs

@@ -67,8 +67,8 @@ protected override void OnLoad()
             GL.GetInteger(GetPName.MaxVertexAttribs, out int maxAttributeCount);
             Debug.WriteLine($"Maximum number of vertex attributes supported: {maxAttributeCount}");
 
-            _shader = new Shader("Shaders/shader.vert", "Shaders/shader.frag");
-            _shader.Use();
+            _shader = Shader.FromFile("Shaders/shader.vert", "Shaders/shader.frag");
+            GL.UseProgram(_shader.Handle);
         }
 
         protected override void OnRenderFrame(FrameEventArgs e)
@@ -77,7 +77,7 @@ protected override void OnRenderFrame(FrameEventArgs e)
 
             GL.Clear(ClearBufferMask.ColorBufferBit);
 
-            _shader.Use();
+            GL.UseProgram(_shader.Handle);
 
             GL.BindVertexArray(_vertexArrayObject);
 

Chapter1/4-Shaders-Uniforms/Shaders/shader.vert

@@ -1,9 +1,9 @@
 #version 330 core
 
-layout(location = 0) in vec3 aPosition;  // the position variable has attribute position 0
+layout(location = 0) in vec3 aPos;  // the position variable has attribute position 0
 
 void main(void)
 {
 	// see how we directly give a vec3 to vec4's constructor
-    gl_Position = vec4(aPosition, 1.0); 
+    gl_Position = vec4(aPos, 1.0); 
 }

Chapter1/4-Shaders-Uniforms/Window.cs

@@ -56,8 +56,8 @@ protected override void OnLoad()
             GL.GetInteger(GetPName.MaxVertexAttribs, out int maxAttributeCount);
             Debug.WriteLine($"Maximum number of vertex attributes supported: {maxAttributeCount}");
 
-            _shader = new Shader("Shaders/shader.vert", "Shaders/shader.frag");
-            _shader.Use();
+            _shader = Shader.FromFile("Shaders/shader.vert", "Shaders/shader.frag");
+            GL.UseProgram(_shader.Handle);
 
             // We start the stopwatch here as this method is only called once.
             _timer = new Stopwatch();
@@ -70,7 +70,7 @@ protected override void OnRenderFrame(FrameEventArgs e)
 
             GL.Clear(ClearBufferMask.ColorBufferBit);
 
-            _shader.Use();
+            GL.UseProgram(_shader.Handle);
 
             // Here, we get the total seconds that have elapsed since the last time this method has reset
             // and we assign it to the timeValue variable so it can be used for the pulsating color.

Chapter1/5-Textures/Shaders/shader.vert

@@ -1,6 +1,6 @@
 #version 330 core
 
-layout(location = 0) in vec3 aPosition;
+layout(location = 0) in vec3 aPos;
 
 // We add another input variable for the texture coordinates.
 
@@ -18,5 +18,5 @@ void main(void)
 
     texCoord = aTexCoord;
 
-    gl_Position = vec4(aPosition, 1.0);
+    gl_Position = vec4(aPos, 1.0);
 }

Chapter1/5-Textures/Window.cs

@@ -35,7 +35,7 @@ public class Window : GameWindow
         private Shader _shader;
 
         // For documentation on this, check Texture.cs.
-        private Texture _texture;
+        private int _texture;
 
         public Window(GameWindowSettings gameWindowSettings, NativeWindowSettings nativeWindowSettings)
             : base(gameWindowSettings, nativeWindowSettings)
@@ -60,25 +60,26 @@ protected override void OnLoad()
             GL.BufferData(BufferTarget.ElementArrayBuffer, _indices.Length * sizeof(uint), _indices, BufferUsageHint.StaticDraw);
 
             // The shaders have been modified to include the texture coordinates, check them out after finishing the OnLoad function.
-            _shader = new Shader("Shaders/shader.vert", "Shaders/shader.frag");
-            _shader.Use();
+            _shader = Shader.FromFile("Shaders/shader.vert", "Shaders/shader.frag");
+            GL.UseProgram(_shader.Handle);
 
             // Because there's now 5 floats between the start of the first vertex and the start of the second,
             // we modify the stride from 3 * sizeof(float) to 5 * sizeof(float).
             // This will now pass the new vertex array to the buffer.
-            var vertexLocation = _shader.GetAttribLocation("aPosition");
+            var vertexLocation = 0; // The location of aPos
             GL.EnableVertexAttribArray(vertexLocation);
             GL.VertexAttribPointer(vertexLocation, 3, VertexAttribPointerType.Float, false, 5 * sizeof(float), 0);
 
             // Next, we also setup texture coordinates. It works in much the same way.
             // We add an offset of 3, since the texture coordinates comes after the position data.
             // We also change the amount of data to 2 because there's only 2 floats for texture coordinates.
-            var texCoordLocation = _shader.GetAttribLocation("aTexCoord");
+            var texCoordLocation = 1; // The location of aTexCoord
             GL.EnableVertexAttribArray(texCoordLocation);
             GL.VertexAttribPointer(texCoordLocation, 2, VertexAttribPointerType.Float, false, 5 * sizeof(float), 3 * sizeof(float));
 
             _texture = Texture.LoadFromFile("Resources/container.png");
-            _texture.Use(TextureUnit.Texture0);
+            GL.ActiveTexture(TextureUnit.Texture0);
+            GL.BindTexture(TextureTarget.Texture2D, _texture);
         }
 
         protected override void OnRenderFrame(FrameEventArgs e)
@@ -89,8 +90,10 @@ protected override void OnRenderFrame(FrameEventArgs e)
 
             GL.BindVertexArray(_vertexArrayObject);
 
-            _texture.Use(TextureUnit.Texture0);
-            _shader.Use();
+            GL.ActiveTexture(TextureUnit.Texture0);
+            GL.BindTexture(TextureTarget.Texture2D, _texture);
+
+            GL.UseProgram(_shader.Handle);
 
             GL.DrawElements(PrimitiveType.Triangles, _indices.Length, DrawElementsType.UnsignedInt, 0);
 

Chapter1/6-MultipleTextures/Shaders/shader.vert

@@ -1,6 +1,6 @@
 #version 330 core
 
-layout(location = 0) in vec3 aPosition;
+layout(location = 0) in vec3 aPos;
 
 layout(location = 1) in vec2 aTexCoord;
 
@@ -10,5 +10,5 @@ void main(void)
 {
     texCoord = aTexCoord;
 
-    gl_Position = vec4(aPosition, 1.0);
+    gl_Position = vec4(aPos, 1.0);
 }

Chapter1/6-MultipleTextures/Window.cs

@@ -31,9 +31,9 @@ public class Window : GameWindow
 
         private Shader _shader;
 
-        private Texture _texture;
+        private int _texture;
 
-        private Texture _texture2;
+        private int _texture2;
 
         public Window(GameWindowSettings gameWindowSettings, NativeWindowSettings nativeWindowSettings)
             : base(gameWindowSettings, nativeWindowSettings)
@@ -58,31 +58,36 @@ protected override void OnLoad()
             GL.BufferData(BufferTarget.ElementArrayBuffer, _indices.Length * sizeof(uint), _indices, BufferUsageHint.StaticDraw);
 
             // shader.frag has been modified yet again, take a look at it as well.
-            _shader = new Shader("Shaders/shader.vert", "Shaders/shader.frag");
-            _shader.Use();
+            _shader = Shader.FromFile("Shaders/shader.vert", "Shaders/shader.frag");
+            GL.UseProgram(_shader.Handle);
 
-            var vertexLocation = _shader.GetAttribLocation("aPosition");
+            var vertexLocation = 0; // The location of aPos
             GL.EnableVertexAttribArray(vertexLocation);
             GL.VertexAttribPointer(vertexLocation, 3, VertexAttribPointerType.Float, false, 5 * sizeof(float), 0);
 
-            var texCoordLocation = _shader.GetAttribLocation("aTexCoord");
+            var texCoordLocation = 1; // The location of aTexCoord
             GL.EnableVertexAttribArray(texCoordLocation);
             GL.VertexAttribPointer(texCoordLocation, 2, VertexAttribPointerType.Float, false, 5 * sizeof(float), 3 * sizeof(float));
 
             _texture = Texture.LoadFromFile("Resources/container.png");
             // Texture units are explained in Texture.cs, at the Use function.
             // First texture goes in texture unit 0.
-            _texture.Use(TextureUnit.Texture0);
+
+            // First we use GL.ActiveTexture to tell OpenGL which texture unit we would like following commands to use.
+            GL.ActiveTexture(TextureUnit.Texture0);
+            // Then we bind our first texture to the 0th texture unit as a 2D texture.
+            GL.BindTexture(TextureTarget.Texture2D, _texture);
 
             // This is helpful because System.Drawing reads the pixels differently than OpenGL expects.
             _texture2 = Texture.LoadFromFile("Resources/awesomeface.png");
             // Then, the second goes in texture unit 1.
-            _texture2.Use(TextureUnit.Texture1);
+            GL.ActiveTexture(TextureUnit.Texture1);
+            GL.BindTexture(TextureTarget.Texture2D, _texture2);
 
-            // Next, we must setup the samplers in the shaders to use the right textures.
+            // Next, we must setup the samplers in the shaders to use the right texture units.
             // The int we send to the uniform indicates which texture unit the sampler should use.
-            _shader.SetInt("texture0", 0);
-            _shader.SetInt("texture1", 1);
+            GL.Uniform1(_shader.UniformLocations["texture0"], 0);
+            GL.Uniform1(_shader.UniformLocations["texture1"], 1);
         }
 
         protected override void OnRenderFrame(FrameEventArgs e)
@@ -93,9 +98,12 @@ protected override void OnRenderFrame(FrameEventArgs e)
 
             GL.BindVertexArray(_vertexArrayObject);
 
-            _texture.Use(TextureUnit.Texture0);
-            _texture2.Use(TextureUnit.Texture1);
-            _shader.Use();
+            GL.ActiveTexture(TextureUnit.Texture0);
+            GL.BindTexture(TextureTarget.Texture2D, _texture);
+            GL.ActiveTexture(TextureUnit.Texture1);
+            GL.BindTexture(TextureTarget.Texture2D, _texture2);
+
+            GL.UseProgram(_shader.Handle);
 
             GL.DrawElements(PrimitiveType.Triangles, _indices.Length, DrawElementsType.UnsignedInt, 0);
 

Chapter1/7-Transformations/Shaders/shader.vert

@@ -1,6 +1,6 @@
 #version 330 core
 
-layout(location = 0) in vec3 aPosition;
+layout(location = 0) in vec3 aPos;
 
 layout(location = 1) in vec2 aTexCoord;
 
@@ -14,5 +14,5 @@ void main(void)
     texCoord = aTexCoord;
 
     // Then all you have to do is multiply the vertices by the transformation matrix, and you'll see your transformation in the scene!
-    gl_Position = vec4(aPosition, 1.0) * transform;
+    gl_Position = vec4(aPos, 1.0) * transform;
 }