Again, my usual disclaimer: I am not an expert, I learned this as I wrote StarSmasher so I can’t promise anything I do is the best way to do it, and as always if you know a better way please let me/everyone know.

My draw script does the following (keep in mind this is part of a class so it refers to self and member data of the class but I think it should be fairly self explanatory):

	//Check that this model isn't already loaded, we don't need to unnecessarily load it.
	if (lastModel != self) {
		//Loads the vertex array into OpenGL ES:
		glVertexPointer(3, GL_FLOAT, 0, facesArray);
		if (hasTexCoords) {
			glBindTexture(GL_TEXTURE_2D, texture[0]); //texture[0] is an OpenGL texture id, loaded by my class during its init method.
			glTexCoordPointer(2, GL_FLOAT, 0, textureCoordsArray);
		}
		lastModel = self;
	}
	//Draw the model:
	glDrawArrays(GL_TRIANGLES, 0, facesCount*3);

For those of you who haven’t played TouchFighter, it’s pretty pointless as a game. It is a turret based game, which essentially means your ship never moves. You change your ships rotation by tilting the device but the only moving parts are the enemy ships that come screaming at you. In other words there is less gameplay value there than the Free Flight version of StarSmasher.

The StarSmasher game engine is 100% my coding, with thanks to the guys in the #iphonedev freenode rooms for helping me solve some particular OpenGL problems, and isn’t even the same style of game as TF. Yeah TF is a space shooter, but the similarities end there for the most part. SS is about dodging asteroids and flying with style while TF, which really has no “flying,” is about accurately aiming your iPhone at targets moving towards you on the screen.

I just can’t understand why people who have never played StarSmasher or TF would rate SS poorly on iTunes. I think people saw the TF video and thought it was amazing because it was really the first video demonstrating the iPhone’s accelerometer controls, but that is it, a demo.

Oh well, there is nothing I can do about it, people will continue to think that SS is TF.
[/rant]

more kjv.sql | sqlite3 kjv.db

For some reason this was giving me errors at lines that when entered by hand weren’t having problems. Since this is, obviously, a huge database I can’t go and fix all these manually. The kjv.sql file was written for MySQL so what I ended up doing was this:

First, I downloaded MAMP (a Mac OS X/Apache/MySQL/PHP one-click installation) because I knew I’d probably want it later and it doesn’t require any type of installation and/or configuration to get MySQL running. I then started the MAMP servers (via MAMP.app). Then I used MAMP’s phpMyAdmin installation to import my kjv.sql file. Then I exported the entire database to a CSV file which was delimited by ‘@’ signs and didn’t put any quotes around the data. The only problem with doing it this way is that carriage returns in the database are treated by sqlite3 as new entries. Fortunately for me this only occurred once. I went into the file with vi, jumped directly to the problem line, got rid of the rogue newlines, and then everything was ready for import.

To import you need to first create your table in your database using sqlite3. After that you run a command similar to:

sqlite3 -separator @ kjv.db “.import kjv_db2-1.csv BibleTable”

If there is an easier way to do this, I’m all ears.

Now I’ve implemented just in time texture loading for the menu screens that checks if the texture is loaded on draw and loads it if necessary. When a menu screen is exited (for instance by tapping the “done” button) I unload the texture (with glDeleteTextures). Below is the TextureLoader class I wrote to manage my textures.

I’m not sure if this is or isn’t a good way to do this, but you are welcome to use it and/or make suggestions. Also, because of the NDA, there is one line that is SDK specific that I have removed. It is:

        textureImage = getCGImageForImageNamed(name);

in TextureLoader.m. You will need to replace this line with the way to get a CGImage for whichever platform you are using. For Mac OS X look at this page. For the iPhone SDK refer to Apple’s documentation and example code. Also you will need to #import the appropriate libraries in TextureImage.h to load textureImage.

Enjoy… and again, I welcome suggestions, I’ve still got loads to learn about graphics development.

This stuff is licensed by:

TextureLoader.m by John Bowers, espressoSoft.com is licensed under a Creative Commons Attribution-Share Alike 3.0 United States License.

TextureLoader.h

//
//  TextureLoader.h
//  Starfield
//
//  Created by John Bowers on 8/3/08.
//  Copyright 2008 John Bowers. Some rights reserved.
//

@interface TextureLoader : NSObject {

}
+ (void) initialize;
+ (GLuint) textureWithName:(NSString*)name;
+ (BOOL) textureIsLoaded:(NSString*)name;
+ (void) unloadTexture:(NSString*)name;
@end

TextureLoader.m

//
//  TextureLoader.m
//  Starfield
//
//  Created by John Bowers on 8/3/08.
//  Copyright 2008 John Bowers. All rights reserved.
//

#import "TextureLoader.h"

static NSMutableDictionary* gameTextures;

@implementation TextureLoader

+ (void) initialize {
    gameTextures = [NSMutableDictionary new];
}

+ (BOOL) textureIsLoaded:(NSString*)name {
    return [gameTextures objectForKey:name] != nil;
}

+ (GLuint) textureWithName:(NSString*)name {
    NSNumber *textureNumber = [gameTextures objectForKey:name];
    if (textureNumber) {
        return [textureNumber unsignedIntValue];
    } else {
        //Load the texture:
        GLuint texture[1];
        CGImageRef textureImage;
        CGContextRef textureContext;
        GLubyte *textureData;
        size_t textureWidth, textureHeight;

        textureImage = getCGImageForImageNamed(name);
        textureWidth = CGImageGetWidth(textureImage);
        textureHeight = CGImageGetHeight(textureImage);

        if (textureImage) {
            textureData = (GLubyte*) malloc(textureWidth*textureHeight*4);
            textureContext = CGBitmapContextCreate(textureData, textureWidth, textureHeight, 8, textureWidth*4, CGImageGetColorSpace(textureImage), kCGImageAlphaPremultipliedLast);

            CGContextDrawImage(textureContext, CGRectMake(0.0, 0.0, (CGFloat)textureWidth, (CGFloat)textureHeight), textureImage);
            CGContextRelease(textureContext);

            glGenTextures(1, texture);
            glBindTexture(GL_TEXTURE_2D, texture[0]);
            glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, textureWidth, textureHeight, 0, GL_RGBA, GL_UNSIGNED_BYTE, textureData);

            free(textureData);
            glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
        }

        [gameTextures setObject:[NSNumber numberWithUnsignedInt:texture[0]] forKey:name];
        return texture[0];
    }
}

+ (void) unloadTexture:(NSString*)name {
    NSNumber *textureNumber = [gameTextures objectForKey:name];
    if (textureNumber) {
        [gameTextures removeObjectForKey:name];
        GLuint texture[1];
        texture[0] = [textureNumber unsignedIntValue];
        glDeleteTextures(1, texture);
    }
}

@end

The game is out for review, link coming soon. Above is the screenshot I chose for the App Store.

Note: Just in case you didn’t catch it above the mesh you are exporting needs to be triangulated (via ‘Ctrl+T’) and have UV texture coordinates (in UV Face Select mode hit ‘U’ and choose some sort of UV unwrapping, if it doesn’t the script will crash instead of exiting gracefully).

To install this python script save it to the /.blender/scripts/ directory (on Mac OS X this is Blender.app/Contents/MacOS/.blender/scripts/). I called it export_objc.py. Also, if you make any modifications to the script, (say add some logic to only add UV texturing if it has been set, or to automatically triangulate the mesh please let me know, I’d love to update this code).

#!BPY

"""
Name: 'OpenGL ES/ObjC export (.h)...'
Blender: 245
Group: 'Export'
Tooltip: 'Export selected mesh to an OpenGL|ES ObjC static array (*.h)'
"""

__author__ = "John Bowers (quadelirus)"
__url__ = ("blender", "Author's homepage, http://www.espressosoft.com")
__version__ = "1.0"

__bpydoc__ = """\
This script exports meshes into two static GLfloat arrays
that can be used to render the model in an OpenGL|ES application.

I designed it as a helper script for some code I am writing for the
iPhone.
"""

# $Id:
#
# Copyright (c) 2008 John Bowers
# http://www.espressosoft.com
# July 13, 2008

# ***** BEGIN GPL LICENSE BLOCK *****
#
# 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 2
# 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, write to the Free Software Foundation,
# Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
#
# ***** END GPL LICENCE BLOCK *****

import Blender
import BPyMessages

def write_header(filename):
     file = open(filename, 'wb')
     scn = Blender.Scene.GetCurrent()
     object = scn.objects.active
     if not object or object.type != 'Mesh':
          BPyMessages.Error_NoMeshActive()
          return
     mesh = object.getData(mesh=1)
     file.write("/*********************************************************\n")
     file.write(" * Exported using the ObjC exporter from espressoSoft.com\n")
     file.write(" * Written by: John Bowers\n")
     file.write(" * \n")
     file.write(" * Model: " + object.name)
     file.write("********************************************************/\n")
     #write the faces:
     file.write("static GLfloat " + object.name + "_vertData[] = {\n”)
     for face in mesh.faces:
          file.write(”\t” + str(face.verts[0].co.x) + “, ” + str(face.verts[0].co.y) + “, ” + str(face.verts[0].co.z) + “, “)
          file.write(str(face.verts[1].co.x) + “, ” + str(face.verts[1].co.y) + “, ” + str(face.verts[1].co.z) + “, “)
          file.write(str(face.verts[2].co.x) + “, ” + str(face.verts[2].co.y) + “, ” + str(face.verts[2].co.z) + “,\n”)
     file.write(”};\n”)
     file.write(”static GLfloat ” + object.name + “_texData[] = {\n”)
     for face in mesh.faces:
          file.write(”\t” + str(face.uv[0][0]) + “, ” + str(face.uv[0][1]) + “, “)
          file.write(str(face.uv[1][0]) + “, ” + str(face.uv[1][1]) + “, “)
          file.write(str(face.uv[2][0]) + “, ” + str(face.uv[2][1]) + “,\n”)
     file.write(”};\n”)
     file.write(”int ” + object.name + “_facesCount = ” + str(len(mesh.faces)) + “;\n”)
     file.close()

def fs_callback(filename):
     if not filename.lower().endswith(’.h’): filename += ‘.h’
     write_header(filename)

Blender.Window.FileSelector(fs_callback, “Export ObjC *.h File”, Blender.sys.makename(ext=’.h’))

UPDATE: after rewriting a major portion of the game controller and the object models the game is now running at a smooth 28 fps. Looks and feels great.

Enemy ships attacking from the space station.

New Laser Model

One More for an Even 3.