From ea73765a5f4e11694f889f8b2c21560e3ccda9b2 Mon Sep 17 00:00:00 2001
From: Nick Gasson <nick@nickg.me.uk>
Date: Sun, 16 Jan 2011 15:38:21 +0000
Subject: [PATCH] Simple noise texture

---
 include/ITexture.hpp |  7 ++--
 src/Map.cpp          |  7 ++--
 src/NoiseTexture.cpp | 77 ++++++++++++++++++++++++++++++++++++++++++++
 src/Texture.cpp      |  6 ++--
 4 files changed, 87 insertions(+), 10 deletions(-)
 create mode 100644 src/NoiseTexture.cpp

diff --git a/include/ITexture.hpp b/include/ITexture.hpp
index 67e1866..3c298ef 100644
--- a/include/ITexture.hpp
+++ b/include/ITexture.hpp
@@ -1,5 +1,5 @@
 //
-//  Copyright (C) 2009  Nick Gasson
+//  Copyright (C) 2009-2011  Nick Gasson
 //
 //  This program is free software: you can redistribute it and/or modify
 //  it under the terms of the GNU General Public License as published by
@@ -28,7 +28,7 @@ struct ITexture {
    virtual ~ITexture() {}
 
    // Bind this texture to the current OpenGL texture
-   virtual void bind() const = 0;
+   virtual void bind() = 0;
    
    virtual int width() const = 0;
    virtual int height() const = 0;
@@ -44,4 +44,7 @@ ITexturePtr load_texture(const string& a_file_name);
 // Load a texture from a resource
 ITexturePtr load_texture(IResourcePtr a_res, const string& a_file_name);
 
+// Generate Perlin noise
+ITexturePtr make_noise_texture(int width, int height);
+
 #endif
diff --git a/src/Map.cpp b/src/Map.cpp
index dc0a7e5..c47ad7b 100644
--- a/src/Map.cpp
+++ b/src/Map.cpp
@@ -650,6 +650,8 @@ void Map::build_mesh(int id, Point<int> bot_left, Point<int> top_right)
    // the meshes are built on the same frame
    ++frame_num;
 
+   buf->bind(make_noise_texture(256, 256));
+   
    for (int x = top_right.x-1; x >= bot_left.x; x--) {
       for (int y = bot_left.y; y < top_right.y; y++) {
          int indexes[4];
@@ -671,11 +673,6 @@ void Map::build_mesh(int id, Point<int> bot_left, Point<int> top_right)
             tex_coords[1], tex_coords[2], tex_coords[3],
             tex_coords[3], tex_coords[0], tex_coords[1]
          };
-
-         if (random() % 2 == 0)
-            buf->bind(load_texture("test2.png"));
-         else
-            buf->bind(load_texture("test.png"));   
          
          for (int i = 0; i < 6; i++) {
             const HeightMap& v = height_map[order[i]];
diff --git a/src/NoiseTexture.cpp b/src/NoiseTexture.cpp
new file mode 100644
index 0000000..19320aa
--- /dev/null
+++ b/src/NoiseTexture.cpp
@@ -0,0 +1,77 @@
+//
+//  Copyright (C) 2011  Nick Gasson
+//
+//  This program is free software: you can redistribute it and/or modify
+//  it under the terms of the GNU General Public License as published by
+//  the Free Software Foundation, either version 3 of the License, or
+//  (at your option) any later version.
+//
+//  This program 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 General Public License for more details.
+//
+//  You should have received a copy of the GNU General Public License
+//  along with this program.  If not, see <http://www.gnu.org/licenses/>.
+//
+
+#include "ITexture.hpp"
+#include "ILogger.hpp"
+#include "OpenGLHelper.hpp"
+
+#include <cstdlib> // XXX
+
+class NoiseTexture : public ITexture {
+public:
+   NoiseTexture(int w, int h);
+   ~NoiseTexture();
+
+   // ITexture interface
+   void bind();
+   int width() const { return width_; }
+   int height() const { return height_; }
+
+private:
+   const int width_, height_;
+   GLuint texture;
+};
+
+NoiseTexture::NoiseTexture(int w, int h)
+   : width_(w), height_(h)
+{
+   GLubyte* pixels = new GLubyte[w * h];
+
+   for (int x = 0; x < w; x++) {
+      for (int y = 0; y < h; y++)
+         pixels[x + (y*w)] = 127 + (random() % 32) - 16;
+   }
+   
+   glGenTextures(1, &texture);
+   glBindTexture(GL_TEXTURE_2D, texture);
+
+   // Use GL_NEAREST here for better performance
+   // Or GL_LINEAR for better apppearance
+   glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
+   glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
+
+   // Load the surface's data into the texture
+   glTexImage2D(GL_TEXTURE_2D, 0, 3, w, h, 0,
+                GL_LUMINANCE, GL_UNSIGNED_BYTE, pixels);
+
+   delete[] pixels;
+}
+
+NoiseTexture::~NoiseTexture()
+{
+   glDeleteTextures(1, &texture);
+}
+
+void NoiseTexture::bind()
+{
+   glBindTexture(GL_TEXTURE_2D, texture);
+}
+
+ITexturePtr make_noise_texture(int width, int height)
+{
+   return ITexturePtr(new NoiseTexture(width, height));
+}
diff --git a/src/Texture.cpp b/src/Texture.cpp
index 48e2f5f..c13b59d 100644
--- a/src/Texture.cpp
+++ b/src/Texture.cpp
@@ -33,10 +33,10 @@ using namespace std::tr1;
 class Texture : public ITexture {
 public:
    Texture(const string &file);
-   virtual ~Texture();
+   ~Texture();
 
    GLuint texture() const { return my_texture; }
-   void bind() const;
+   void bind();
    
    int width() const { return my_width; }
    int height() const { return my_height; }
@@ -168,7 +168,7 @@ bool Texture::is_texture_sizeSupported(int width, int height, int ncols, GLenum
    return height != 0 && width != 0;
 }
 
-void Texture::bind() const
+void Texture::bind()
 {
    glBindTexture(GL_TEXTURE_2D, my_texture);
 }
-- 
2.39.2