Create normals and actually use texture

exercise3/include/terrain.h

@@ -1,12 +1,12 @@
 //
-// This source code is property of the Computer Graphics and Visualization 
+// This source code is property of the Computer Graphics and Visualization
-// chair of the TU Dresden. Do not distribute in modified or unmodified form! 
+// chair of the TU Dresden. Do not distribute in modified or unmodified form!
 // Copyright (C) 2016 CGV TU Dresden - All Rights Reserved
 //
 /*************************************************************************
 Terrain.
 This class represents a textured and shaded terrain. Both, the texture
-and the height map is read from a bmp file (in the constructor). 
+and the height map is read from a bmp file (in the constructor).
 The height map is mapped to a regular grid consisting of triangle strips.
 During rendering the normals needed for lighting are calculated.
 There are some additional rendering modes:
@@ -18,7 +18,7 @@ The rendering is done in the "render" method which sets the projection
 and view via "setup_projection" and the light via "setup_light".
 Depending on the settings (that can be changed using "set_show_solid",
 "set_show_wireframe" and "set_show_levels") different passes are rendered
-using the appropriate rendering method ("render_solid_terrain", 
+using the appropriate rendering method ("render_solid_terrain",
 "render_wireframe_terrain", "render_level_lines"). They call the
 "render_terrain" method.
 *************************************************************************/
@@ -92,7 +92,10 @@ private:
 	// Create height lines for the level "level"
 	void create_level_line(int level);
 
-	
+	void push_point(int x, int y);
+	vec3d create_point(int x, int y);
+	vec2d texture_coord(int x, int y);
+
 	// Load the height map from the file "filename"
 	bool load_heightmap(const char *filename);
 	// Return the width of the height map

exercise3/src/terrain.cpp

@@ -1,6 +1,6 @@
 //
-// This source code is property of the Computer Graphics and Visualization 
+// This source code is property of the Computer Graphics and Visualization
-// chair of the TU Dresden. Do not distribute in modified or unmodified form! 
+// chair of the TU Dresden. Do not distribute in modified or unmodified form!
 // Copyright (C) 2016 CGV TU Dresden - All Rights Reserved
 //
 #include "terrain.h"
@@ -112,8 +112,9 @@ void terrain::render_solid_terrain()
 
 
 
-
+   	glEnable(GL_TEXTURE_2D);
-
+	glActiveTexture(GL_TEXTURE0);
+   	glBindTexture(GL_TEXTURE0, texture_handle);
 
 	// Set the material color to white
 	glColor3d(1, 1, 1);
@@ -123,7 +124,7 @@ void terrain::render_solid_terrain()
 	// Disable texture mapping
 	glDisable(GL_TEXTURE_2D);
 	// Disable support for depth buffer offsets
-	glDisable(GL_POLYGON_OFFSET_FILL); 
+	glDisable(GL_POLYGON_OFFSET_FILL);
 	// Disable lighting
 	glDisable(GL_LIGHTING);
 }
@@ -141,13 +142,18 @@ void terrain::render_wireframe_terrain()
 	// Set the color to black
 	glColor3d(0, 0, 0);
 	// Render the terrain
-	render_terrain(); 
+	render_terrain();
 
 	// Set the draw mode to fill polygons
 	glPolygonMode(GL_FRONT_AND_BACK, GL_FILL);
 }
 
-
+void terrain::push_point(int x, int y)
+{
+	set_normal(x, y);
+	glTexCoord2dv(texture_coord(x, y));
+	glVertex3dv(create_point(x, y));
+}
 
 // Render the terrain
 void terrain::render_terrain()
@@ -175,7 +181,7 @@ void terrain::render_terrain()
 				   and translated to use the values of the variables "x" and "y"
 				   defined below directly as coordinates. The initial height of
 				   the grid shall be 0.
-	Aufgabe 2.2.1. Vervollstaendigen Sie den nachfolgenden Quelltext um die 
+	Aufgabe 2.2.1. Vervollstaendigen Sie den nachfolgenden Quelltext um die
 	               Erstellung eines regelmaessigen Gitters das sich ueber die
 				   X-Z-Ebene erstreckt. Erstellen Sie dieses Gitter, indem Sie
 				   zeilenweise Dreiecksstreifen definieren. Das Koordinatensystem
@@ -184,23 +190,23 @@ void terrain::render_terrain()
 				   als Koordinaten einsetzen koennen. Das Gitter soll zunaechst
 				   eine Hoehe von 0 besitzen.
 
-	
+
 	Task 2.2.2.    Now elevate the height of the vertices to create the grid terrain
 	               that corresponds to the height map. Use "get_heightmap_value(x, y)".
     Aufgabe 2.2.2. Heben Sie jetzt die Vertices an um ein Drahtgitterterrain zu erstellen,
-	               das zur Hoehenkarte korrespondiert. Nutzen Sie die Methode 
+	               das zur Hoehenkarte korrespondiert. Nutzen Sie die Methode
 				   "get_heightmap_value(x, y)".
 
 
-	Task 2.2.3.    Make sure to call "set_normal" for every vertex and continue this 
+	Task 2.2.3.    Make sure to call "set_normal" for every vertex and continue this
 	               task in "set_normal".
     Aufgabe 2.2.3. Stellen Sie sicher, dass Sie "set_normal" f<EFBFBD>r jeden Vertex aufrufen
 	               und fahren Sie in "set_normal" mit der Aufgabe fort.
 
 
-    Task 2.2.4.    Activate texture mapping and bind the texture in the method 
+    Task 2.2.4.    Activate texture mapping and bind the texture in the method
 	               "render_solid_terrain". Provide 2D texture coordinates per vertex in
-				   this method using "glTexCoord2d". 
+				   this method using "glTexCoord2d".
     Aufgabe 2.2.4. Aktivieren Sie Texturmapping und binden Sie eine Textur in der
 	               Methode "render_solid_terrain". Spezifizieren Sie in dieser Methode pro
 				   Vertex eine Texturkoordinate mittels der Methode "glTexCoord2d".
@@ -214,8 +220,8 @@ void terrain::render_terrain()
 
 		// Draw one strip
 		for (int x = 0; x < map_width; x++) {
-			glVertex3f(static_cast<float>(x), get_heightmap_value(x, y), static_cast<float>(y));
+			push_point(x, y);
-			glVertex3f(static_cast<float>(x), get_heightmap_value(x, y + 1), static_cast<float>(y) + 1.0f);
+			push_point(x, y + 1);
 		}
 
 		glEnd();
@@ -224,8 +230,30 @@ void terrain::render_terrain()
 	glPopMatrix();
 }
 
+vec2d terrain::texture_coord(int x, int y)
+{
+	return vec2d(
+		static_cast<double>(x) / static_cast<double>(get_heightmap_width()),
+		static_cast<double>(y) / static_cast<double>(get_heightmap_height())
+	);
+}
 
+vec3d terrain::create_point(int x, int y)
+{
+	return vec3d(
+		static_cast<double>(x),
+		static_cast<double>(get_heightmap_value(x, y)),
+		static_cast<double>(y)
+	);
+}
 
+vec3d calculate_normal(vec3d middle, vec3d p0, vec3d p1)
+{
+	vec3d v0 = middle - p0;
+	vec3d v1 = p1 - middle;
+
+	return cross(v0, v1);
+}
 
 // Calculate and set the normal for height map entry (x,y)
 void terrain::set_normal(int x, int y)
@@ -235,8 +263,8 @@ void terrain::set_normal(int x, int y)
 	               the height map value (x, y). You can either use forward differences,
 				   backward differences or central differences. The latter will give
 				   the best results. The calculation is done by first determining direction
-				   vectors in X and Z and then using vector operations to get a vector that 
+				   vectors in X and Z and then using vector operations to get a vector that
-				   is perpendicular to both. You find some examples for vector operations in 
+				   is perpendicular to both. You find some examples for vector operations in
 				   this project below. Do not forget to pass the normal to OpenGL using
 				   the command glNormal3d.
 
@@ -246,7 +274,7 @@ void terrain::set_normal(int x, int y)
 				   Fuer die Berechnung werden zunaechst Richtungvektoren in X- und Z-Richtung
 				   gebildet und anschliessend mittels Vektoroperationen ein zu beiden Vektoren
 				   senkrechter Vektor berechnet. Nachfolgend ein paar Beispiele fuer Vektor-
-				   rechnungen in diesem Projekt. Vergessen Sie nicht die Normale nach der 
+				   rechnungen in diesem Projekt. Vergessen Sie nicht die Normale nach der
 				   Berechnung mittels glNormal3d an OpenGL zu senden.
 
 				   // Create a vector
@@ -270,6 +298,22 @@ void terrain::set_normal(int x, int y)
 				   double y = vec3.y();
 				   double z = vec3.z();
    *****************/
+
+	vec3d middle = create_point(x, y);
+
+	vec3d right = create_point(x + 1, y);
+	vec3d top = create_point(x, y + 1);
+	vec3d left = create_point(x - 1, y);
+	vec3d bottom = create_point(x, y - 1);
+
+	vec3d normal0 = calculate_normal(middle, right, top);
+	vec3d normal1 = calculate_normal(middle, top, left);
+	vec3d normal2 = calculate_normal(middle, left, bottom);
+	vec3d normal3 = calculate_normal(middle, bottom, right);
+
+	vec3d final_normal = (normal0 + normal1 + normal2 + normal3) / 4;
+
+	glNormal3dv(final_normal);
 }
 
 
@@ -312,8 +356,8 @@ void terrain::render_level_lines()
 void terrain::create_level_line(int level)
 {
 	/********
-	Additional Task: Find iso lines with the "Marching Squares" algorithm for the 
+	Additional Task: Find iso lines with the "Marching Squares" algorithm for the
-	                 height value "level". Store the start and end points of the 
+	                 height value "level". Store the start and end points of the
 					 found lines in the list "level_lines".
     Zusatzaufgabe:   Finden Sie Hoehenlinien mittels des "Marching Squares"-Algorithmus
 	                 fuer den Hoehenwert "level". Legen Sie die Start- und Endpunkte
@@ -350,7 +394,7 @@ void terrain::setup_light()
 	glLightfv(GL_LIGHT0, GL_DIFFUSE, diffuse_color);
 	glLightfv(GL_LIGHT0, GL_SPECULAR, specular_color);
 
-	glLightf(GL_LIGHT0,GL_SPOT_EXPONENT, 10.0f);   
+	glLightf(GL_LIGHT0,GL_SPOT_EXPONENT, 10.0f);
 
 	glPopMatrix();
 
@@ -403,7 +447,7 @@ void terrain::set_show_solid(bool state)
 void terrain::set_show_wireframe(bool state)
 {
 	show_wireframe = state;
-	// The current display list is outdated now	
+	// The current display list is outdated now
 	dl_valid = false;
 }
 
@@ -442,7 +486,7 @@ bool terrain::load_heightmap(const char *filename)
 	}
 
 	// All went well...
-	return true;	
+	return true;
 }
 
 
@@ -476,7 +520,7 @@ bool terrain::load_texture(const char *filename, GLuint *handle)
 	// Clamp the texture at the borders
 	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP);
 	// Transfer the image data to the graphics card.
-	glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB, BMP_GetWidth(bitmap), BMP_GetHeight(bitmap), 0, GL_RGB, GL_UNSIGNED_BYTE, data);	
+	glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB, BMP_GetWidth(bitmap), BMP_GetHeight(bitmap), 0, GL_RGB, GL_UNSIGNED_BYTE, data);
 
 	// Not needed anymore
 	free(data);