/*
* This file is a port of com.jhlabs.image.EmbossFilter.java
* Copyright 2006 Jerry Huxtable
*
* emboss.c
* Copyright 2012 Janne Liljeblad
*
* This file is a Frei0r plugin.
*
* 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., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
#include <stdlib.h>
#include <assert.h>
#include <math.h>
#include "frei0r.h"
#include "frei0r_math.h"
double PI = 3.14159;
double pixelScale = 255.9;
typedef struct emboss_instance
{
unsigned int width;
unsigned int height;
double azimuth;
double elevation;
double width45;
} emboss_instance_t;
int f0r_init()
{
return 1;
}
void f0r_deinit()
{ /* no initialization required */ }
void f0r_get_plugin_info(f0r_plugin_info_t* emposs_info)
{
emposs_info->name = "emboss";
emposs_info->author = "Janne Liljeblad";
emposs_info->plugin_type = F0R_PLUGIN_TYPE_FILTER;
emposs_info->color_model = F0R_COLOR_MODEL_RGBA8888;
emposs_info->frei0r_version = FREI0R_MAJOR_VERSION;
emposs_info->major_version = 0;
emposs_info->minor_version = 1;
emposs_info->num_params = 3;
emposs_info->explanation = "Creates embossed relief image of source image";
}
void f0r_get_param_info(f0r_param_info_t* info, int param_index)
{
switch(param_index)
{
case 0:
info->name = "azimuth";
info->type = F0R_PARAM_DOUBLE;
info->explanation = "Light direction";
break;
case 1:
info->name = "elevation";
info->type = F0R_PARAM_DOUBLE;
info->explanation = "Background lightness";
break;
case 2:
info->name = "width45";
info->type = F0R_PARAM_DOUBLE;
info->explanation = "Bump height";
break;
}
}
f0r_instance_t f0r_construct(unsigned int width, unsigned int height)
{
emboss_instance_t* inst = (emboss_instance_t*)calloc(1, sizeof(*inst));
inst->width = width;
inst->height = height;
inst->azimuth = 135.0 / 360.0; //input range 0 - 1 will be interpreted as angle 0 - 360
inst->elevation = 30.0 / 90.0;//input range 0 - 1 will be interpreted as lighness value 0 - 90
inst->width45 = 10.0 / 40.0;//input range 0 - 1 will be interpreted as bump height value 1 - 40
return (f0r_instance_t)inst;
}
void f0r_destruct(f0r_instance_t instance)
{
free(instance);
}
void f0r_set_param_value(f0r_instance_t instance,
f0r_param_t param, int param_index)
{
assert(instance);
emboss_instance_t* inst = (emboss_instance_t*)instance;
switch(param_index)
{
case 0:
inst->azimuth = *((double*)param);
break;
case 1:
inst->elevation = *((double*)param);
break;
case 2:
inst->width45 = *((double*)param);
break;
}
}
void f0r_get_param_value(f0r_instance_t instance,
f0r_param_t param, int param_index)
{
assert(instance);
emboss_instance_t* inst = (emboss_instance_t*)instance;
switch(param_index)
{
case 0:
*((double*)param) = inst->azimuth;
break;
case 1:
*((double*)param) = inst->elevation;
break;
case 2:
*((double*)param) = inst->width45;
break;
}
}
void f0r_update(f0r_instance_t instance, double time,
const uint32_t* inframe, uint32_t* outframe)
{
// Check and cast instance
assert(instance);
emboss_instance_t* inst = (emboss_instance_t*)instance;
// Get render params values 0.0-1.0 in range used by filter
double azimuthInput = inst->azimuth * 360.0;
double elevationInput = inst->elevation * 90.0;
double widthInput = inst->width45 * 40.0;
// Force correct ranges on input
azimuthInput = CLAMP(azimuthInput, 0.0, 360.0);
elevationInput = CLAMP(elevationInput, 0.0, 90.0);
widthInput = CLAMP(widthInput, 1.0, 40.0);
// Convert to filter input values
double azimuth = azimuthInput * PI / 180.0;
double elevation = elevationInput * PI / 180.0;
double width45 = widthInput;
// Create brightness image
unsigned int len = inst->width * inst->height;
unsigned char bumpPixels[len];
unsigned char alphaVals[len];
unsigned int index, r, g, b, a = 0;
const unsigned char* src = (unsigned char*)inframe;
while (len--)
{
r = *src++;
g = *src++;
b = *src++;
a = *src++;
bumpPixels[index++] = (r + g + b)/3;
alphaVals[index - 1] = a;
}
// Create embossed image from brightness image
unsigned char* dst = (unsigned char*)outframe;
unsigned char shade, background = 0;
int Nx, Ny, Nz, Lx, Ly, Lz, Nz2, NzLz, NdotL;
Lx = (int)(cos(azimuth) * cos(elevation) * pixelScale);
Ly = (int)(sin(azimuth) * cos(elevation) * pixelScale);
Lz = (int)(sin(elevation) * pixelScale);
Nz = (int)(6 * 255 / width45);
Nz2 = Nz * Nz;
NzLz = Nz * Lz;
background = Lz;
int bumpIndex = 0;
int width = inst->width;
int height = inst->height;
int s1, s2, s3 = 0;
int x, y = 0;
for (y = 0; y < height; y++, bumpIndex += width)
{
s1 = bumpIndex;
s2 = s1 + width;
s3 = s2 + width;
for (x = 0; x < width; x++, s1++, s2++, s3++)
{
if (y != 0 && y < height-2 && x != 0 && x < width-2)
{
Nx = bumpPixels[s1-1] + bumpPixels[s2-1] + bumpPixels[s3-1] - bumpPixels[s1+1] - bumpPixels[s2+1] - bumpPixels[s3+1];
Ny = bumpPixels[s3-1] + bumpPixels[s3] + bumpPixels[s3+1] - bumpPixels[s1-1] - bumpPixels[s1] - bumpPixels[s1+1];
if (Nx == 0 && Ny == 0)
shade = background;
else if ((NdotL = Nx*Lx + Ny*Ly + NzLz) < 0)
shade = 0;
else
shade = (int)(NdotL / sqrt(Nx*Nx + Ny*Ny + Nz2));
}
else
{
shade = background;
}
// Write value
*dst++ = shade;
*dst++ = shade;
*dst++ = shade;
*dst++ = alphaVals[s1]; //copy alpha
}
}
}