From 163b963b1d6c1d0d288e27aeb978ff521a241917 Mon Sep 17 00:00:00 2001
From: Kyle K <kylek389@gmail.com>
Date: Sun, 3 Oct 2010 18:30:04 -0500
Subject: Initial commit

---
 lib/gltools.cpp | 651 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 651 insertions(+)
 create mode 100644 lib/gltools.cpp

(limited to 'lib/gltools.cpp')

diff --git a/lib/gltools.cpp b/lib/gltools.cpp
new file mode 100644
index 0000000..bcdd957
--- /dev/null
+++ b/lib/gltools.cpp
@@ -0,0 +1,651 @@
+/*
+ *  gltools.c
+ *  Block
+ *
+ *  Created by Richard Wright on 10/16/06.
+ *  OpenGL SuperBible, 4th Edition
+ *
+ */
+
+#include "gltools.h"
+#include "math3d.h"
+#include <assert.h>
+
+///////////////////////////////////////////////////////////////////////////////
+// Get the OpenGL version number
+bool gltGetOpenGLVersion(int &nMajor, int &nMinor)
+{
+    const char *szVersionString = (const char *)glGetString(GL_VERSION);
+    if (szVersionString == NULL)
+    {
+        nMajor = 0;
+        nMinor = 0;
+        return false;
+    }
+    
+    // Get major version number. This stops at the first non numeric character
+    nMajor = atoi(szVersionString);
+    
+    // Get minor version number. Start past the first ".", atoi terminates on first non numeric char.
+    nMinor = atoi(strstr(szVersionString, ".")+1);
+    
+    return true;
+}
+
+///////////////////////////////////////////////////////////////////////////////
+// This function determines if the named OpenGL Extension is supported
+// Returns 1 or 0
+int gltIsExtSupported(const char *extension)
+{
+    GLubyte *extensions = NULL;
+    const GLubyte *start;
+    GLubyte *where, *terminator;
+    
+    where = (GLubyte *) strchr(extension, ' ');
+    if (where || *extension == '\0')
+        return 0;
+    
+    extensions = (GLubyte *)glGetString(GL_EXTENSIONS);
+    
+    start = extensions;
+    for (;;) 
+    {
+        where = (GLubyte *) strstr((const char *) start, extension);
+        
+        if (!where)
+            break;
+        
+        terminator = where + strlen(extension);
+        
+        if (where == start || *(where - 1) == ' ') 
+        {
+            if (*terminator == ' ' || *terminator == '\0') 
+                return 1;
+        }
+        start = terminator;
+    }
+    return 0;
+}
+
+#ifdef _WIN32
+///////////////////////////////////////////////////////////////////////////////
+// Win32 Only, check for WGL extension
+#include "wglext.h"
+int gltIsWGLExtSupported(HDC hDC, const char *szExtension)
+{
+    GLubyte *extensions = NULL;
+    const GLubyte *start;
+    GLubyte *where, *terminator;
+    PFNWGLGETEXTENSIONSSTRINGARBPROC wglGetExtensionsStringARB;
+    
+    // Just look or the entry point
+    wglGetExtensionsStringARB = (PFNWGLGETEXTENSIONSSTRINGARBPROC)wglGetProcAddress("wglGetExtensionsStringARB");
+    if (wglGetExtensionsStringARB == NULL)
+        return 0;
+    
+    where = (GLubyte *) strchr(szExtension, ' ');
+    if (where || *szExtension == '\0')
+        return 0;
+    
+    extensions = (GLubyte *)wglGetExtensionsStringARB(hDC);
+    
+    start = extensions;
+    for (;;) 
+    {
+        where = (GLubyte *) strstr((const char *) start, szExtension);
+        
+        if (!where)
+            break;
+        
+        terminator = where + strlen(szExtension);
+        
+        if (where == start || *(where - 1) == ' ') 
+        {
+            if (*terminator == ' ' || *terminator == '\0') 
+                return 1;
+        }
+        start = terminator;
+    }
+    return 0;
+}
+#endif
+
+/////////////////////////////////////////////////////////////
+// Get a pointer to an OpenGL extension
+// Note on the Mac, this does a lot of work that could be saved
+// if you call this function repeatedly. Write your own function that
+// gets the bundle once, gets all the function pointers, then releases
+// the bundle.
+void *gltGetExtensionPointer(const char *szExtensionName)
+{
+#ifdef WIN32
+    // Well, this one is simple. An OpenGL context must be
+    // current first. Returns NULL if extension not supported
+    return (void *)wglGetProcAddress(szExtensionName);
+#endif
+    
+#ifdef linux
+    // Pretty much ditto above
+    return (void *)glXGetProcAddress((GLubyte *)szExtensionName);
+#endif
+
+#ifdef __APPLE__
+    // Mac is a bit more tricky.
+    // First we need the bundle
+    CFBundleRef openGL = 0;
+    SInt16      fwVersion = 0;
+    SInt32      fwDir = 0;
+    
+    if (FindFolder(kSystemDomain, kFrameworksFolderType, kDontCreateFolder, &fwVersion, &fwDir) != noErr)
+        return NULL;
+    
+    FSSpec fSpec;
+    FSRef  fRef;
+    if (FSMakeFSSpec(fwVersion, fwDir, "\pOpenGL.framework", &fSpec) != noErr)
+        return NULL;
+    
+    FSpMakeFSRef(&fSpec, &fRef);
+    CFURLRef url = CFURLCreateFromFSRef(kCFAllocatorDefault, &fRef);
+    if (!url)
+        return NULL;
+    
+    openGL = CFBundleCreate(kCFAllocatorDefault, url);
+    CFRelease(url);
+    
+    // Then load the function pointer from the bundle
+    CFStringRef string = CFStringCreateWithCString(kCFAllocatorDefault, szExtensionName, kCFStringEncodingMacRoman);
+    void *pFunc = CFBundleGetFunctionPointerForName(openGL, string);
+    
+    // Release the bundle and string
+    CFRelease(string);
+    CFRelease(openGL);
+    
+    // Return the function ponter
+    return pFunc;
+#endif    
+}
+
+///////////////////////////////////////////////////////////////////
+// Draw the unit axis. A small white sphere represents the origin
+// and the three axes are colored Red, Green, and Blue, which 
+// corresponds to positive X, Y, and Z respectively. Each axis has
+// an arrow on the end, and normals are provided should the axes
+// be lit. These are all built using the quadric shapes. For best
+// results, put this in a display list.
+void gltDrawUnitAxes(void)
+{
+    GLUquadricObj *pObj;    // Temporary, used for quadrics
+    
+    // Measurements
+    float fAxisRadius = 0.025f;
+    float fAxisHeight = 1.0f;
+    float fArrowRadius = 0.06f;
+    float fArrowHeight = 0.1f;
+    
+    // Setup the quadric object
+    pObj = gluNewQuadric();
+    gluQuadricDrawStyle(pObj, GLU_FILL);
+    gluQuadricNormals(pObj, GLU_SMOOTH);
+    gluQuadricOrientation(pObj, GLU_OUTSIDE);
+    gluQuadricTexture(pObj, GLU_FALSE);
+    
+    ///////////////////////////////////////////////////////
+    // Draw the blue Z axis first, with arrowed head
+    glColor3f(0.0f, 0.0f, 1.0f);
+    gluCylinder(pObj, fAxisRadius, fAxisRadius, fAxisHeight, 10, 1);
+    glPushMatrix();
+    glTranslatef(0.0f, 0.0f, 1.0f);
+    gluCylinder(pObj, fArrowRadius, 0.0f, fArrowHeight, 10, 1);
+    glRotatef(180.0f, 1.0f, 0.0f, 0.0f);
+    gluDisk(pObj, fAxisRadius, fArrowRadius, 10, 1);
+    glPopMatrix();
+    
+    ///////////////////////////////////////////////////////
+    // Draw the Red X axis 2nd, with arrowed head
+    glColor3f(1.0f, 0.0f, 0.0f);
+    glPushMatrix();
+    glRotatef(90.0f, 0.0f, 1.0f, 0.0f);
+    gluCylinder(pObj, fAxisRadius, fAxisRadius, fAxisHeight, 10, 1);
+    glPushMatrix();
+    glTranslatef(0.0f, 0.0f, 1.0f);
+    gluCylinder(pObj, fArrowRadius, 0.0f, fArrowHeight, 10, 1);
+    glRotatef(180.0f, 0.0f, 1.0f, 0.0f);
+    gluDisk(pObj, fAxisRadius, fArrowRadius, 10, 1);
+    glPopMatrix();
+    glPopMatrix();
+    
+    ///////////////////////////////////////////////////////
+    // Draw the Green Y axis 3rd, with arrowed head
+    glColor3f(0.0f, 1.0f, 0.0f);
+    glPushMatrix();
+    glRotatef(-90.0f, 1.0f, 0.0f, 0.0f);
+    gluCylinder(pObj, fAxisRadius, fAxisRadius, fAxisHeight, 10, 1);
+    glPushMatrix();
+    glTranslatef(0.0f, 0.0f, 1.0f);
+    gluCylinder(pObj, fArrowRadius, 0.0f, fArrowHeight, 10, 1);
+    glRotatef(180.0f, 1.0f, 0.0f, 0.0f);
+    gluDisk(pObj, fAxisRadius, fArrowRadius, 10, 1);
+    glPopMatrix();
+    glPopMatrix();
+    
+    ////////////////////////////////////////////////////////
+    // White Sphere at origin
+    glColor3f(1.0f, 1.0f, 1.0f);
+    gluSphere(pObj, 0.05f, 15, 15);
+    
+    // Delete the quadric
+    gluDeleteQuadric(pObj);
+}
+
+// For best results, put this in a display list
+// Draw a torus (doughnut)  at z = fZVal... torus is in xy plane
+void gltDrawTorus(GLfloat majorRadius, GLfloat minorRadius, GLint numMajor, GLint numMinor)
+{
+    M3DVector3f vNormal;
+    double majorStep = 2.0f*M3D_PI / numMajor;
+    double minorStep = 2.0f*M3D_PI / numMinor;
+    int i, j;
+    
+    for (i=0; i<numMajor; ++i) 
+    {
+        double a0 = i * majorStep;
+        double a1 = a0 + majorStep;
+        GLfloat x0 = (GLfloat) cos(a0);
+        GLfloat y0 = (GLfloat) sin(a0);
+        GLfloat x1 = (GLfloat) cos(a1);
+        GLfloat y1 = (GLfloat) sin(a1);
+        
+        glBegin(GL_TRIANGLE_STRIP);
+        for (j=0; j<=numMinor; ++j) 
+        {
+            double b = j * minorStep;
+            GLfloat c = (GLfloat) cos(b);
+            GLfloat r = minorRadius * c + majorRadius;
+            GLfloat z = minorRadius * (GLfloat) sin(b);
+            
+            // First point
+            glTexCoord2f((float)(i)/(float)(numMajor), (float)(j)/(float)(numMinor));
+            vNormal[0] = x0*c;
+            vNormal[1] = y0*c;
+            vNormal[2] = z/minorRadius;
+            m3dNormalizeVector(vNormal);
+            glNormal3fv(vNormal);
+            glVertex3f(x0*r, y0*r, z);
+            
+            glTexCoord2f((float)(i+1)/(float)(numMajor), (float)(j)/(float)(numMinor));
+            vNormal[0] = x1*c;
+            vNormal[1] = y1*c;
+            vNormal[2] = z/minorRadius;
+            m3dNormalizeVector(vNormal);
+            glNormal3fv(vNormal);
+            glVertex3f(x1*r, y1*r, z);
+        }
+        glEnd();
+    }
+}
+
+// For best results, put this in a display list
+// Draw a sphere at the origin
+void gltDrawSphere(GLfloat fRadius, GLint iSlices, GLint iStacks)
+{
+    GLfloat drho = (GLfloat)(3.141592653589) / (GLfloat) iStacks;
+    GLfloat dtheta = 2.0f * (GLfloat)(3.141592653589) / (GLfloat) iSlices;
+    GLfloat ds = 1.0f / (GLfloat) iSlices;
+    GLfloat dt = 1.0f / (GLfloat) iStacks;
+    GLfloat t = 1.0f;    
+    GLfloat s = 0.0f;
+    GLint i, j;     // Looping variables
+    
+    for (i = 0; i < iStacks; i++) 
+    {
+        GLfloat rho = (GLfloat)i * drho;
+        GLfloat srho = (GLfloat)(sin(rho));
+        GLfloat crho = (GLfloat)(cos(rho));
+        GLfloat srhodrho = (GLfloat)(sin(rho + drho));
+        GLfloat crhodrho = (GLfloat)(cos(rho + drho));
+        
+        // Many sources of OpenGL sphere drawing code uses a triangle fan
+        // for the caps of the sphere. This however introduces texturing 
+        // artifacts at the poles on some OpenGL implementations
+        glBegin(GL_TRIANGLE_STRIP);
+        s = 0.0f;
+        for ( j = 0; j <= iSlices; j++) 
+        {
+            GLfloat theta = (j == iSlices) ? 0.0f : j * dtheta;
+            GLfloat stheta = (GLfloat)(-sin(theta));
+            GLfloat ctheta = (GLfloat)(cos(theta));
+            
+            GLfloat x = stheta * srho;
+            GLfloat y = ctheta * srho;
+            GLfloat z = crho;
+            
+            glTexCoord2f(s, t);
+            glNormal3f(x, y, z);
+            glVertex3f(x * fRadius, y * fRadius, z * fRadius);
+            
+            x = stheta * srhodrho;
+            y = ctheta * srhodrho;
+            z = crhodrho;
+            glTexCoord2f(s, t - dt);
+            s += ds;
+            glNormal3f(x, y, z);
+            glVertex3f(x * fRadius, y * fRadius, z * fRadius);
+        }
+        glEnd();
+
+        t -= dt;
+    }
+}
+
+// Define targa header. This is only used locally.
+#pragma pack(1)
+typedef struct
+{
+    GLbyte    identsize;              // Size of ID field that follows header (0)
+    GLbyte    colorMapType;           // 0 = None, 1 = paletted
+    GLbyte    imageType;              // 0 = none, 1 = indexed, 2 = rgb, 3 = grey, +8=rle
+    unsigned short    colorMapStart;  // First colour map entry
+    unsigned short    colorMapLength; // Number of colors
+    unsigned char     colorMapBits;   // bits per palette entry
+    unsigned short    xstart;         // image x origin
+    unsigned short    ystart;         // image y origin
+    unsigned short    width;          // width in pixels
+    unsigned short    height;         // height in pixels
+    GLbyte    bits;                   // bits per pixel (8 16, 24, 32)
+    GLbyte    descriptor;             // image descriptor
+} TGAHEADER;
+#pragma pack(8)
+
+////////////////////////////////////////////////////////////////////
+// Capture the current viewport and save it as a targa file.
+// Be sure and call SwapBuffers for double buffered contexts or
+// glFinish for single buffered contexts before calling this function.
+// Returns 0 if an error occurs, or 1 on success.
+GLint gltWriteTGA(const char *szFileName)
+{
+    FILE *pFile;                // File pointer
+    TGAHEADER tgaHeader;        // TGA file header
+    unsigned long lImageSize;   // Size in bytes of image
+    GLbyte    *pBits = NULL;    // Pointer to bits
+    GLint iViewport[4];         // Viewport in pixels
+    GLenum lastBuffer;          // Storage for the current read buffer setting
+    
+    // Get the viewport dimensions
+    glGetIntegerv(GL_VIEWPORT, iViewport);
+    
+    // How big is the image going to be (targas are tightly packed)
+    lImageSize = iViewport[2] * 3 * iViewport[3];    
+    
+    // Allocate block. If this doesn't work, go home
+    pBits = (GLbyte *)malloc(lImageSize);
+    if (pBits == NULL)
+        return 0;
+    
+    // Read bits from color buffer
+    glPixelStorei(GL_PACK_ALIGNMENT, 1);
+    glPixelStorei(GL_PACK_ROW_LENGTH, 0);
+    glPixelStorei(GL_PACK_SKIP_ROWS, 0);
+    glPixelStorei(GL_PACK_SKIP_PIXELS, 0);
+    
+    // Get the current read buffer setting and save it. Switch to
+    // the front buffer and do the read operation. Finally, restore
+    // the read buffer state
+    glGetIntegerv(GL_READ_BUFFER, (GLint *)&lastBuffer);
+    glReadBuffer(GL_FRONT);
+    glReadPixels(0, 0, iViewport[2], iViewport[3], GL_BGR_EXT, GL_UNSIGNED_BYTE, pBits);
+    glReadBuffer(lastBuffer);
+    
+    // Initialize the Targa header
+    tgaHeader.identsize = 0;
+    tgaHeader.colorMapType = 0;
+    tgaHeader.imageType = 2;
+    tgaHeader.colorMapStart = 0;
+    tgaHeader.colorMapLength = 0;
+    tgaHeader.colorMapBits = 0;
+    tgaHeader.xstart = 0;
+    tgaHeader.ystart = 0;
+    tgaHeader.width = iViewport[2];
+    tgaHeader.height = iViewport[3];
+    tgaHeader.bits = 24;
+    tgaHeader.descriptor = 0;
+    
+    // Do byte swap for big vs little endian
+#ifdef __APPLE__
+    LITTLE_ENDIAN_WORD(&tgaHeader.colorMapStart);
+    LITTLE_ENDIAN_WORD(&tgaHeader.colorMapLength);
+    LITTLE_ENDIAN_WORD(&tgaHeader.xstart);
+    LITTLE_ENDIAN_WORD(&tgaHeader.ystart);
+    LITTLE_ENDIAN_WORD(&tgaHeader.width);
+    LITTLE_ENDIAN_WORD(&tgaHeader.height);
+#endif
+    
+    // Attempt to open the file
+    pFile = fopen(szFileName, "wb");
+    if (pFile == NULL)
+    {
+        free(pBits);    // Free buffer and return error
+        return 0;
+    }
+    
+    // Write the header
+    fwrite(&tgaHeader, sizeof(TGAHEADER), 1, pFile);
+    
+    // Write the image data
+    fwrite(pBits, lImageSize, 1, pFile);
+    
+    // Free temporary buffer and close the file
+    free(pBits);    
+    fclose(pFile);
+    
+    // Success!
+    return 1;
+}
+
+////////////////////////////////////////////////////////////////////
+// Allocate memory and load targa bits. Returns pointer to new buffer,
+// height, and width of texture, and the OpenGL format of data.
+// Call free() on buffer when finished!
+// This only works on pretty vanilla targas... 8, 24, or 32 bit color
+// only, no palettes, no RLE encoding.
+GLbyte *gltLoadTGA(const char *szFileName, GLint *iWidth, GLint *iHeight, GLint *iComponents, GLenum *eFormat)
+{
+    FILE *pFile;              // File pointer
+    TGAHEADER tgaHeader;      // TGA file header
+    unsigned long lImageSize; // Size in bytes of image
+    short sDepth;             // Pixel depth;
+    GLbyte    *pBits = NULL;  // Pointer to bits
+    
+    // Default/Failed values
+    *iWidth = 0;
+    *iHeight = 0;
+    *eFormat = GL_BGR_EXT;
+    *iComponents = GL_RGB8;
+    
+    // Attempt to open the fil
+    pFile = fopen(szFileName, "rb");
+    if (pFile == NULL)
+        return NULL;
+    
+    // Read in header (binary)
+    fread(&tgaHeader, 18/* sizeof(TGAHEADER)*/, 1, pFile);
+    
+    // Do byte swap for big vs little endian
+#ifdef __APPLE__
+    LITTLE_ENDIAN_WORD(&tgaHeader.colorMapStart);
+    LITTLE_ENDIAN_WORD(&tgaHeader.colorMapLength);
+    LITTLE_ENDIAN_WORD(&tgaHeader.xstart);
+    LITTLE_ENDIAN_WORD(&tgaHeader.ystart);
+    LITTLE_ENDIAN_WORD(&tgaHeader.width);
+    LITTLE_ENDIAN_WORD(&tgaHeader.height);
+#endif
+
+    // Get width, height, and depth of texture
+    *iWidth = tgaHeader.width;
+    *iHeight = tgaHeader.height;
+    sDepth = tgaHeader.bits / 8;
+    
+    // Put some validity checks here. Very simply, I only understand
+    // or care about 8, 24, or 32 bit targa's.
+    if (tgaHeader.bits != 8 && tgaHeader.bits != 24 && tgaHeader.bits != 32)
+        return NULL;
+    
+    // Calculate size of image buffer
+    lImageSize = tgaHeader.width * tgaHeader.height * sDepth;
+    
+    // Allocate memory and check for success
+    pBits = (GLbyte*)malloc(lImageSize * sizeof(GLbyte));
+    if (pBits == NULL)
+        return NULL;
+    
+    // Read in the bits
+    // Check for read error. This should catch RLE or other 
+    // weird formats that I don't want to recognize
+    if (fread(pBits, lImageSize, 1, pFile) != 1)
+    {
+        free(pBits);
+        return NULL;
+    }
+    
+    // Set OpenGL format expected
+    switch(sDepth)
+    {
+        case 3:     // Most likely case
+            *eFormat = GL_BGR_EXT;
+            *iComponents = GL_RGB8;
+            break;
+        case 4:
+            *eFormat = GL_BGRA_EXT;
+            *iComponents = GL_RGBA8;
+            break;
+        case 1:
+            *eFormat = GL_LUMINANCE;
+            *iComponents = GL_LUMINANCE8;
+            break;
+    };
+
+    // Done with File
+    fclose(pFile);
+    
+    // Return pointer to image data
+    return pBits;
+}
+
+// Rather than malloc/free a block everytime a shader must be loaded,
+// I will dedicate a single 4k page for reading in shaders. Thanks to
+// modern OS design, this page will be swapped out to disk later if never
+// used again after program initialization. Where-as mallocing different size
+// shader blocks could lead to heap fragmentation, which would actually be worse.
+//#define MAX_SHADER_LENGTH   4096  -> This is defined in gltools.h
+static GLubyte shaderText[MAX_SHADER_LENGTH];
+
+////////////////////////////////////////////////////////////////
+// Load the shader from the specified file. Returns false if the
+// shader could not be loaded
+bool bLoadShaderFile(const char *szFile, GLhandleARB shader)
+{
+    GLint shaderLength = 0;
+    FILE *fp;
+    GLcharARB *fsStringPtr[1];
+    
+    // Open the shader file
+    fp = fopen(szFile, "r");
+    if (fp != NULL)
+    {
+        // See how long the file s
+        while (fgetc(fp) != EOF)
+            shaderLength++;
+        
+        // Allocate a block of memory to send in the shader
+        assert(shaderLength < MAX_SHADER_LENGTH);   // make me bigger!
+        if (shaderLength > MAX_SHADER_LENGTH)
+        {
+            fclose(fp);
+            return false;
+        }
+        
+        // Go back to beginning of file
+        rewind(fp);
+        
+        // Read the whole file in
+        if (shaderText != NULL)
+            fread(shaderText, 1, shaderLength, fp);
+        
+        // Make sure it is null terminated and close the file
+        shaderText[shaderLength] = '\0';
+        fclose(fp);
+    }
+    else
+        return false;
+
+    // Load the string
+    fsStringPtr[0] = (GLcharARB *)shaderText;
+    glShaderSourceARB(shader, 1, (const GLcharARB **)fsStringPtr, NULL);
+    
+    return true;
+}   
+
+/////////////////////////////////////////////////////////////////
+// Load a pair of shaders, compile, and link together. Specify the complete
+// path and file name of each ASCII shader file. Note, there is no support for
+// just loading say a vertex program... you have to do both.
+GLhandleARB gltLoadShaderPair(const char *szVertexProg, const char *szFragmentProg)
+{
+    // Temporary Shader objects
+    GLhandleARB hVertexShader;
+    GLhandleARB hFragmentShader; 
+    GLhandleARB hReturn = 0;   
+    GLint testVal;
+    
+    // Create shader objects
+    hVertexShader = glCreateShaderObjectARB(GL_VERTEX_SHADER_ARB);
+    hFragmentShader = glCreateShaderObjectARB(GL_FRAGMENT_SHADER_ARB);
+    
+    // Load them. If fail clean up and return null
+    if (bLoadShaderFile(szVertexProg, hVertexShader) == false)
+    {
+        glDeleteObjectARB(hVertexShader);
+        glDeleteObjectARB(hFragmentShader);
+        return 0;
+    }
+    
+    if (bLoadShaderFile(szFragmentProg, hFragmentShader) == false)
+    {
+        glDeleteObjectARB(hVertexShader);
+        glDeleteObjectARB(hFragmentShader);
+        return 0;
+    }
+    
+    // Compile them
+    glCompileShaderARB(hVertexShader);
+    glCompileShaderARB(hFragmentShader);
+    
+    // Check for errors
+    glGetObjectParameterivARB(hVertexShader, GL_OBJECT_COMPILE_STATUS_ARB, &testVal);
+    if (testVal == GL_FALSE)
+    {
+        glDeleteObjectARB(hVertexShader);
+        glDeleteObjectARB(hFragmentShader);
+        return 0;
+    }
+    
+    glGetObjectParameterivARB(hFragmentShader, GL_OBJECT_COMPILE_STATUS_ARB, &testVal);
+    if (testVal == GL_FALSE)
+    {
+        glDeleteObjectARB(hVertexShader);
+        glDeleteObjectARB(hFragmentShader);
+        return 0;
+    }
+    
+    // Link them - assuming it works...
+    hReturn = glCreateProgramObjectARB();
+    glAttachObjectARB(hReturn, hVertexShader);
+    glAttachObjectARB(hReturn, hFragmentShader);
+    glLinkProgramARB(hReturn);
+    
+    // These are no longer needed
+    glDeleteObjectARB(hVertexShader);
+    glDeleteObjectARB(hFragmentShader);  
+    
+    return hReturn;  
+}   
+
-- 
cgit v1.2.3