/*
  Shader make_named_framebuffers

  Define mental ray framebuffers in version 3.6.x using a geometry
  shader to modify the options block.  For example:

  instance "framebuffer_creation"
      geometry
          "make_named_framebuffers" (
              "framebuffers" [
                  { "name" "diffuse",
                    "type" "rgba_16",
		    "filtering" on,
		    "filename" "buffer_0.tif" },
		  { "name" "specular",
		    "type" "rgba_16",
		    "filtering" on,
		    "filename" "buffer_1.tif" },
                  { "name" "indirect",
		    "type" "rgba_16",
		    "filtering" on,
		    "filename" "buffer_2.tif" }
	      ]
	  )
  end instance
*/

#define _CRT_SECURE_NO_WARNINGS

#include <sstream>
#include <vector>
#include "shader.h"
#include "geoshader.h"
extern "C" {
#include "miaux.h"
}


/* Input parameter for each framebuffer is a struct: */

typedef struct {
    miInteger name;
    miTag type;
    miBoolean filtering;      
    miTag filename;
} named_framebuffer;


/* Parameter struct for shader function: */

struct make_named_framebuffers {
    int i_fb;
    int n_fb;
    named_framebuffer fb[1];
};

extern "C" DLLEXPORT
int make_named_framebuffers_version(void) { return 1; }

/* Struct to store evaluated parameters: */

typedef struct {
    char* name;
    char* type;
    miBoolean filtering;
    char* filename;
} fb_args;


/* Evaluate the parameters required to define framebuffers: */

std::vector<fb_args> get_named_framebuffer_args(
    miState *state, struct make_named_framebuffers *params)
{
    int n_fb = *mi_eval_integer(&params->n_fb);
    int i_fb = *mi_eval_integer(&params->i_fb);    

    mi_info("Making %i user framebuffers:", n_fb);

    std::vector<fb_args> args(n_fb);
    for (int i = 0; i < n_fb; ++i) {
	named_framebuffer p = params->fb[i + i_fb];
	args[i].name = miaux_tag_to_string(*mi_eval_tag(&p.name), NULL);
	args[i].type = miaux_tag_to_string(*mi_eval_tag(&p.type), NULL);
	args[i].filtering = *mi_eval_boolean(&p.filtering);
	args[i].filename = miaux_tag_to_string(*mi_eval_tag(&p.filename), NULL);
	mi_progress("   Buffer %s: filename '%s', type '%s', filtering %s",
		    args[i].name, args[i].filename, args[i].type,
		    args[i].filtering ? "on" : "off");
    }
    return args;
}

/* Shader functions: */

extern "C" DLLEXPORT
miBoolean make_named_framebuffers (
    miTag *result, miState *state, struct make_named_framebuffers *params)
{
    std::vector<fb_args> args = get_named_framebuffer_args(state, params);
    mi::shader::Edit_fb framebuffers(state->camera->buffertag);

    for (unsigned int i = 0; i < args.size(); ++i) {
	framebuffers->set(args[i].name, "datatype", args[i].type);
	framebuffers->set(args[i].name, "filtering", 
			  args[i].filtering ? true : false);
	framebuffers->set(args[i].name, "user", true);
	// A framebuffer could be used by output shader and not
	// written to file, so check for a filename:
	if (args[i].filename && strlen(args[i].filename) > 1) {
	    mi_info ("  ... writes to %s", args[i].filename);
	    framebuffers->set(args[i].name, "filename", args[i].filename);
	}
    }

    return miTRUE;
}