From 13f335523b076ac698511e1a2861598a1a01ed4b Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Vladim=C3=ADr=20Vondru=C5=A1?= <mosra@centrum.cz>
Date: Mon, 19 Mar 2012 16:57:02 +0100
Subject: [PATCH] Added class for managing buffered textures.

---
 src/AbstractShaderProgram.h |  6 +++
 src/BufferedTexture.h       | 97 +++++++++++++++++++++++++++++++++++++
 2 files changed, 103 insertions(+)
 create mode 100644 src/BufferedTexture.h

diff --git a/src/AbstractShaderProgram.h b/src/AbstractShaderProgram.h
index 60e4e92bd..842722f92 100644
--- a/src/AbstractShaderProgram.h
+++ b/src/AbstractShaderProgram.h
@@ -23,6 +23,7 @@
 
 #include "Shader.h"
 #include "AbstractTexture.h"
+#include "BufferedTexture.h"
 
 namespace Magnum {
 
@@ -218,6 +219,11 @@ class MAGNUM_EXPORT AbstractShaderProgram {
             setUniform(location, value->layer());
         }
 
+        /** @copydoc setUniform(GLint, GLint) */
+        void setUniform(GLint location, const BufferedTexture* value) {
+            setUniform(location, value->layer());
+        }
+
     private:
         enum State {
             Initialized,
diff --git a/src/BufferedTexture.h b/src/BufferedTexture.h
new file mode 100644
index 000000000..791719d28
--- /dev/null
+++ b/src/BufferedTexture.h
@@ -0,0 +1,97 @@
+#ifndef Magnum_BufferedTexture_h
+#define Magnum_BufferedTexture_h
+/*
+    Copyright © 2010, 2011, 2012 Vladimír Vondruš <mosra@centrum.cz>
+
+    This file is part of Magnum.
+
+    Magnum is free software: you can redistribute it and/or modify
+    it under the terms of the GNU Lesser General Public License version 3
+    only, as published by the Free Software Foundation.
+
+    Magnum is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+    GNU Lesser General Public License version 3 for more details.
+*/
+
+/** @file
+ * @brief Class Magnum::BufferedTexture
+ */
+
+#include "Renderbuffer.h"
+#include "Buffer.h"
+
+namespace Magnum {
+
+/**
+@brief Buffered texture
+
+This texture is, unlike classic textures such as Texture or CubeMapTexture,
+used as simple data source, without any unneccessary interpolation and
+wrapping methods. Texture data are stored in buffer and after binding the
+buffer to the texture using setBuffer(), you can fill the buffer at any time
+using data setting functions in Buffer itself.
+
+When using buffered texture in the shader, use `samplerBuffer` and fetch the
+data using integer coordinates in `texelFetch()`.
+*/
+class BufferedTexture {
+    BufferedTexture(const BufferedTexture& other) = delete;
+    BufferedTexture(BufferedTexture&& other) = delete;
+    BufferedTexture& operator=(const BufferedTexture& other) = delete;
+    BufferedTexture& operator=(BufferedTexture&& other) = delete;
+
+    public:
+        /** @copydoc Renderbuffer::Components */
+        typedef Renderbuffer::Components Components;
+
+        /** @copydoc Renderbuffer::ComponentType */
+        typedef Renderbuffer::ComponentType ComponentType;
+
+        /**
+         * @brief Constructor
+         * @param layer     %Texture layer (number between 0 and 31)
+         */
+        inline BufferedTexture(GLint layer = 0): _layer(layer) {
+            glActiveTexture(GL_TEXTURE0 + layer);
+            glGenTextures(1, &texture);
+        }
+
+        /** @copydoc AbstractTexture::~AbstractTexture() */
+        inline virtual ~BufferedTexture() {
+            glDeleteTextures(1, &texture);
+        }
+
+        /** @copydoc AbstractTexture::layer() */
+        inline GLint layer() const { return _layer; }
+
+        /** @copydoc AbstractTexture::bind() */
+        inline void bind() const {
+            glActiveTexture(GL_TEXTURE0 + _layer);
+            glBindTexture(GL_TEXTURE_BUFFER, texture);
+        }
+
+        /**
+         * @brief Set texture buffer
+         * @param components    Component count
+         * @param type          Data type per component
+         * @param buffer        %Buffer with data
+         *
+         * Binds given buffer to this texture. The buffer itself can be then
+         * filled with data of proper format at any time using Buffer own data
+         * setting functions.
+         */
+        void setBuffer(Components components, ComponentType type, Buffer* buffer) {
+            bind();
+            glTexBuffer(GL_TEXTURE_BUFFER, components|type, buffer->id());
+        }
+
+    private:
+        GLint _layer;
+        GLuint texture;
+};
+
+}
+
+#endif