Add some xs for gpgpu and _o GL routines

Still need to figure out how to merged this into OpenGL::Modern
in a clean way.  This appears to include the main functions of
concern.

gpgpu_gl.xs

@@ -0,0 +1,246 @@
+/*  Last saved: Mon 07 Aug 2017 04:53:34 PM */
+
+/*  Copyright (c) 1998 Kenneth Albanowski. All rights reserved.
+ *  Copyright (c) 2007 Bob Free. All rights reserved.
+ *  Copyright (c) 2009 Chris Marshall. All rights reserved.
+ *  This program is free software; you can redistribute it and/or
+ *  modify it under the same terms as Perl itself.
+ */
+
+#include <stdio.h>
+
+#include "pgopogl.h"
+
+#ifdef HAVE_GL
+#include "gl_util.h"
+
+/* Note: this is caching procs once for all contexts */
+/* !!! This should instead cache per context */
+#if defined(_WIN32) || (defined(__CYGWIN__) && defined(HAVE_W32API))
+#define loadProc(proc,name) \
+{ \
+  if (!proc) \
+  { \
+    proc = (void *)wglGetProcAddress(name); \
+    if (!proc) croak(name " is not supported by this renderer"); \
+  } \
+}
+#define testProc(proc,name) ((proc) ? 1 : !!(proc = (void *)wglGetProcAddress(name)))
+#else /* not using WGL */
+#define loadProc(proc,name)
+#define testProc(proc,name) 1
+#endif /* not defined _WIN32, __CYGWIN__, and HAVE_W32API */
+#endif /* defined HAVE_GL */
+
+
+/********************/
+/* GPGPU Utils      */
+/********************/
+
+GLint FBO_MAX = -1;
+
+/* Get max GPGPU data size */
+int gpgpu_size(void)
+{
+#if defined(GL_ARB_texture_rectangle) && defined(GL_ARB_texture_float) && \
+  defined(GL_ARB_fragment_program) && defined(GL_EXT_framebuffer_object)
+  if (FBO_MAX == -1)
+  {
+    if (testProc(glProgramStringARB,"glProgramStringARB") &&
+      testProc(glGenProgramsARB,"glGenProgramsARB") &&
+      testProc(glBindProgramARB,"glBindProgramARB") &&
+      testProc(glIsProgramARB,"glIsProgramARB") &&
+      testProc(glProgramLocalParameter4fvARB,"glProgramLocalParameter4fvARB") &&
+      testProc(glDeleteProgramsARB,"glDeleteProgramsARB") &&
+      testProc(glGenFramebuffersEXT,"glGenFramebuffersEXT") &&
+      testProc(glGenRenderbuffersEXT,"glGenRenderbuffersEXT") &&
+      testProc(glBindFramebufferEXT,"glBindFramebufferEXT") &&
+      testProc(glFramebufferTexture2DEXT,"glFramebufferTexture2DEXT") &&
+      testProc(glBindRenderbufferEXT,"glBindRenderbufferEXT") &&
+      testProc(glRenderbufferStorageEXT,"glRenderbufferStorageEXT") &&
+      testProc(glFramebufferRenderbufferEXT,"glFramebufferRenderbufferEXT") &&
+      testProc(glCheckFramebufferStatusEXT,"glCheckFramebufferStatusEXT") &&
+      testProc(glDeleteRenderbuffersEXT,"glDeleteRenderbuffersEXT") &&
+      testProc(glDeleteFramebuffersEXT,"glDeleteFramebuffersEXT"))
+    {
+      glGetIntegerv(GL_MAX_RENDERBUFFER_SIZE_EXT,&FBO_MAX);
+    }
+    else
+    {
+      FBO_MAX = 0;
+    }
+  }
+  return(FBO_MAX);
+#else
+  return(0);
+#endif
+}
+
+/* Get max square array width for a given GPGPU data size */
+int gpgpu_width(int len)
+{
+  int max = gpgpu_size();
+  if (max && len && !(len%3))
+  {
+    int count = len / 3;
+    int w = (int)sqrt(count);
+
+    while ((w <= count) && (w <= max))
+    {
+      if (!(count%w)) return(w);
+      w++;
+    }
+  }
+  return(0);
+}
+
+#ifdef GL_ARB_fragment_program
+static char affine_prog[] =
+  "!!ARBfp1.0\n"
+  "PARAM affine[4] = {program.local[0..3]};\n"
+  "TEMP decal;\n"
+  "TEX decal, fragment.texcoord[0], texture[0], RECT;\n"
+  "MOV decal.w, 1.0;\n"
+  "DP4 result.color.x, decal, affine[0];\n"
+  "DP4 result.color.y, decal, affine[1];\n"
+  "DP4 result.color.z, decal, affine[2];\n"
+  "END\n";
+
+/* Enable affine shader program */
+void enable_affine(oga_struct * oga)
+{
+  if (!oga) return;
+  if (!oga->affine_handle)
+  {
+    /* Load shader program */
+    glGenProgramsARB(1,&oga->affine_handle);
+    glBindProgramARB(GL_FRAGMENT_PROGRAM_ARB,oga->affine_handle);
+    glProgramStringARB(GL_FRAGMENT_PROGRAM_ARB,
+      GL_PROGRAM_FORMAT_ASCII_ARB, strlen(affine_prog),affine_prog);
+
+    /* Validate shader program */
+    if (!glIsProgramARB(oga->affine_handle))
+    {
+      GLint errorPos;
+      glGetIntegerv(GL_PROGRAM_ERROR_POSITION_ARB,&errorPos);
+      if (errorPos < 0) errorPos = strlen(affine_prog);
+      croak("Affine fragment program error\n%s",&affine_prog[errorPos]);
+    }
+  }
+  glEnable(GL_FRAGMENT_PROGRAM_ARB);
+}
+
+/* Disable affine shader program */
+void disable_affine(oga_struct * oga)
+{
+  if (!oga) return;
+  if (oga->affine_handle) glDisable(GL_FRAGMENT_PROGRAM_ARB);
+}
+#endif
+
+#ifdef GL_EXT_framebuffer_object
+/* Unbind an FBO to an OGA */
+void release_fbo(oga_struct * oga)
+{
+  if (oga->fbo_handle)
+  {
+    glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, 0);
+    glDeleteFramebuffersEXT(1,&oga->fbo_handle);
+  }
+
+  if (oga->tex_handle[0] || oga->tex_handle[1])
+  {
+    glBindTexture(oga->target,0);	
+    if (oga->tex_handle[0]) glDeleteTextures(1,&oga->tex_handle[0]);
+    if (oga->tex_handle[1]) glDeleteTextures(1,&oga->tex_handle[1]);
+  }
+}
+
+/* Enable an FBO bound to an OGA */
+void enable_fbo(oga_struct * oga, int w, int h, GLuint target,
+  GLuint pixel_type, GLuint pixel_format, GLuint element_size)
+{
+  if (!oga) return;
+
+  if ((oga->fbo_w != w) || (oga->fbo_h != h) ||
+    (oga->target != target) ||
+    (oga->pixel_type != pixel_type) ||
+    (oga->pixel_format != pixel_format) ||
+    (oga->element_size != element_size)) release_fbo(oga);
+
+  if (!oga->fbo_handle)
+  {
+    GLenum status;
+
+    /* Save params */
+    oga->fbo_w = w;
+    oga->fbo_h = h;
+    oga->target = target;
+    oga->pixel_type = pixel_type;
+    oga->pixel_format = pixel_format;
+    oga->element_size = element_size;
+
+    /* Set up FBO */
+    glGenTextures(2,oga->tex_handle);
+    glGenFramebuffersEXT(1,&oga->fbo_handle);
+    glBindFramebufferEXT(GL_FRAMEBUFFER_EXT,oga->fbo_handle);
+
+    glViewport(0,0,w,h);
+    glMatrixMode(GL_PROJECTION);
+    glLoadIdentity();
+    gluOrtho2D(0,w,0,h);
+    glMatrixMode(GL_MODELVIEW); 
+    glLoadIdentity();
+
+    glBindTexture(target,oga->tex_handle[1]);
+    glTexParameteri(target,GL_TEXTURE_MIN_FILTER,GL_NEAREST);
+    glTexParameteri(target,GL_TEXTURE_MAG_FILTER,GL_NEAREST);
+    glTexParameteri(target,GL_TEXTURE_WRAP_S,GL_CLAMP);
+    glTexParameteri(target,GL_TEXTURE_WRAP_T,GL_CLAMP);
+
+    glTexImage2D(target,0,pixel_type,w,h,0,
+      pixel_format,element_size,0);
+
+    glFramebufferTexture2DEXT(GL_FRAMEBUFFER_EXT,
+      GL_COLOR_ATTACHMENT0_EXT,target,oga->tex_handle[1],0);
+
+    status = glCheckFramebufferStatusEXT(GL_RENDERBUFFER_EXT);
+    if (status) croak("enable_fbo status: %04X\n",status);
+  }
+  else
+  {
+    glBindFramebufferEXT(GL_FRAMEBUFFER_EXT,oga->fbo_handle);
+  }
+
+  /* Load data */
+  glBindTexture(target,oga->tex_handle[0]);
+  glTexImage2D(target,0,pixel_type,w,h,0,
+    pixel_format,element_size,oga->data);
+
+  glEnable(target);
+  //glDrawBuffer(GL_COLOR_ATTACHMENT0_EXT);
+  glBindTexture(target,oga->tex_handle[0]);
+  glTexEnvf(GL_TEXTURE_ENV,GL_TEXTURE_ENV_MODE,GL_DECAL);
+}
+
+/* Disable an FBO bound to an OGA */
+void disable_fbo(oga_struct * oga)
+{
+  if (!oga) return;
+  if (oga->fbo_handle)
+  {
+    glDisable(oga->target);
+    glBindFramebufferEXT(GL_FRAMEBUFFER_EXT,0);
+  }
+}
+#endif
+
+MODULE = OpenGL::Array		PACKAGE = OpenGL::Array
+
+#//# glpHasGPGPU();
+int
+glpHasGPGPU()
+	CODE:
+		RETVAL = gpgpu_size();
+	OUTPUT:
+		RETVAL