view release on metacpan or  search on metacpan

opengl_array.xs  view on Meta::CPAN

		int		fbo_width = 0;
		int		i,j,count,dim,cols;
		SV *		sv = ST(1);
		int		free_mat = 0;

		/* Get transform matrix OGA */
		if (sv != &PL_sv_undef && sv_derived_from(sv,"OpenGL::Array"))
		{
			IV ref = SvIV((SV*)SvRV(sv));
			oga_struct *oga_mat = INT2PTR(OpenGL__Array,ref);
			count = oga_mat->item_count;

			for (i=0;i<oga_mat->type_count;i++)
			{
				if (oga_mat->types[i] != GL_FLOAT)
					croak("Unsupported datatype in affine matrix");
			}

			mat = (GLfloat *)oga_mat->data;
		}
		else
		{
			count = items - 1;
			free_mat = 1;
		}
		if (!count) croak("No matrix values");

		/* Currently only support GLfloat */
		for (i=0;i<oga->type_count;i++)
		{
			if (oga->types[i] != GL_FLOAT)
				croak("Unsupported datatype");
		}

		/* Scalar Multiply */
		if (count == 1)
		{
			GLfloat scalar = mat ? mat[0] : (GLfloat)SvNV(ST(1));
			for (i=0;i<len;i++) data[i] *= scalar;
			XSRETURN_EMPTY;
		}

		/* Calc matrix dimension from sqrt of array size */
		dim = (int)sqrt(count);
		if (count != dim*dim) croak("Not a square matrix");

		/* Affine matrix dimension is one element larger than vector data */
		cols = dim - 1;
		if (len % cols)
			croak("Matrix does not match array vector size");

		/* Grab affine matrix */
		if (!mat)
		{
			mat = malloc(sizeof(GLfloat) * count);
			for (i=0; i<count; i++)
				mat[i] = (GLfloat)SvNV(ST(i+1));
		}
#if 0 /* Need to figure out why this is slower than CPU calcs */ 
		/* Use GPU if FBOs and Fragment Programs are supported */
		fbo_width = gpgpu_width(len);
		if (dim == 4 && fbo_width)
		{
			GLuint target = GL_TEXTURE_RECTANGLE_ARB;
			int w = fbo_width;
			int h = len / (w*3);

			/* Setup and enable FBO */
			enable_fbo(oga,w,h,target,GL_RGB32F_ARB,GL_RGB,GL_FLOAT);

			/* Pass affine matrix to shader */
			enable_affine(oga);
			for (i=0;i<4;i++)
			{
				glProgramLocalParameter4fvARB(GL_FRAGMENT_PROGRAM_ARB,
					i,&mat[i<<2]);
			}

			/* Render to FBO via fragment shader */
			glBegin(GL_QUADS);
			{
				glTexCoord2i(0,0); glVertex2i(0,0);
				glTexCoord2i(w,0); glVertex2i(w,0);
				glTexCoord2i(w,h); glVertex2i(w,h);
				glTexCoord2i(0,h); glVertex2i(0,h);
			}
			glEnd();

			/* Done rendering */
			disable_affine(oga);

			/* Save back to OGA */
			//glReadBuffer(GL_COLOR_ATTACHMENT0_EXT);
			glReadPixels(0,0,w,h,GL_RGB,GL_FLOAT,oga->data);

			disable_fbo(oga);
		}
		/* Use CPU to do transform */
		else
#endif
		{
			int s = sizeof(GLfloat) * cols;
			GLfloat *vec = malloc(s);
			int k,r;

			/* Iterate each data row */
			for (i=0; i < len; i+=cols)
			{
				/* Iterate each result column */
				for (j=0,r=0; j<cols; j++,r+=dim)
				{
					vec[j] = 0.0;

					/* Iterate each matrix column */
					for (k=0; k<cols; k++)
					{
						vec[j] += data[i+k] * mat[r+k];
					}
					/* Matrix translate column */
					vec[j] += mat[r+cols];
				}