#include "togl.h"
#include "material.h"
#include "image.h"
#include "ppm.h"
#include <GL/gl.h>
#include <GL/glu.h>


typedef struct
{
    float ambient[4];
    float diffuse[4];
    float specular[4];
    float emission[4];
    float shininess;
} Material;

// local variables
static Material gMaterials[MAX_NUM_MATERIALS];
static TextureData gTextures[MAX_NUM_TEXTURES];


void make_material(int index, float r, float g, float b, float a, float ambient,
                 float diffuse, float specular, float emission, float shininess)
{
    gMaterials[index].ambient[0] = r*ambient;
    gMaterials[index].ambient[1] = g*ambient;
    gMaterials[index].ambient[2] = b*ambient;
    gMaterials[index].ambient[3] = a;
    gMaterials[index].diffuse[0] = r*diffuse;
    gMaterials[index].diffuse[1] = g*diffuse;
    gMaterials[index].diffuse[2] = b*diffuse;
    gMaterials[index].diffuse[3] = a;
    gMaterials[index].specular[0] = r*specular;
    gMaterials[index].specular[1] = g*specular;
    gMaterials[index].specular[2] = b*specular;
    gMaterials[index].specular[3] = a;
    gMaterials[index].emission[0] = r*emission;
    gMaterials[index].emission[1] = g*emission;
    gMaterials[index].emission[2] = b*emission;
    gMaterials[index].emission[3] = a;
    gMaterials[index].shininess = shininess;
}

void lmbind(int face, int index)
{
    glMaterialfv(face, GL_AMBIENT, gMaterials[index].ambient);
    glMaterialfv(face, GL_DIFFUSE, gMaterials[index].diffuse);
    glMaterialfv(face, GL_SPECULAR, gMaterials[index].specular);
    glMaterialfv(face, GL_EMISSION, gMaterials[index].emission);
    glMaterialf(face, GL_SHININESS, gMaterials[index].shininess);
}

void clear_all_texture()
{
    int i;

    for (i = 0; i < MAX_NUM_TEXTURES; i++) {
        gTextures[i].sizeX = 0;
        gTextures[i].sizeY = 0;
        gTextures[i].sizeZ = 0;
    
        if (gTextures[i].data != NULL) {
            delete[] gTextures[i].data;
        }
    }
}

void clear_texture(int index)
{
    gTextures[index].sizeX = 0;
    gTextures[index].sizeY = 0;
    gTextures[index].sizeZ = 0;

    if (gTextures[index].data != NULL) {
        delete[] gTextures[index].data;
    }
}

int load_texture(int index, char *file)
{
    char extension[4];
    int i, str_len, size, result;
    static int first = 1;

    if (first) {
        for (i = 0; i < MAX_NUM_TEXTURES; i++) {
            gTextures[i].sizeX = 0;
            gTextures[i].sizeY = 0;
            gTextures[i].sizeZ = 0;
            gTextures[i].data = NULL;
        }
        first = 0;
    }

    str_len = strlen(file);
    for(i = 0; i < 3; i++) {
        extension[i] = file[str_len-3+i];
    }
    extension[3] = NULL;

    if (!strcmp(extension, "ppm")) { 
        PpmImage ppm;
        if ((result = LoadPpmFile(file, &ppm)) != 1) {
	    return result;
        }

        size = ppm.width * ppm.height * 3;
        gTextures[index].sizeX = ppm.width;
        gTextures[index].sizeY = ppm.height;
        gTextures[index].sizeZ = 3;
        if (!(gTextures[index].data = new unsigned char[size])) {
            printf("Couldn't allocate memory for texture image pixel\n");
            return -1;
        }
        memcpy(gTextures[index].data, ppm.data, size*sizeof(unsigned char));
        delete[] ppm.data;
    }
    else if (!strcmp(extension, "rgb")) {
        TK_RGBImageRec *rgb;
        if (!(rgb = tkRGBImageLoad(file))) {
            return -1;
        }

        size = rgb->sizeX * rgb->sizeY * rgb->sizeZ;
        gTextures[index].sizeX = rgb->sizeX;
        gTextures[index].sizeY = rgb->sizeY;
        gTextures[index].sizeZ = rgb->sizeZ;
        if (!(gTextures[index].data = new unsigned char[size])) {
            printf("Couldn't allocate memory for texture image pixel\n");
            return -1;
        }
        memcpy(gTextures[index].data, rgb->data, size*sizeof(unsigned char));

        delete[] rgb->data;
        delete rgb;
    }
    else {
        printf("Unrecognizable texture file format, can only be ppm or rgb\n");
        return 0;
    }

    return 1;
}

// sets up the current bound texture to the image specified by
// the image structure pointer img
// if shade is 1, lighting and materials also change the appearance
// otherwise, no lighting effects are shown
void texbind(int dummy, int index)
{
    // the texture image
    // NOTE: height and width must be a power of 2
    glTexImage2D(GL_TEXTURE_2D, 0, gTextures[index].sizeZ, 
                 gTextures[index].sizeX, gTextures[index].sizeY, 0, 
                 gTextures[index].sizeZ==3 ? GL_RGB : GL_RGBA, 
                 GL_UNSIGNED_BYTE, gTextures[index].data);

    // the texture environment
    glTexEnvi(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_MODULATE);

    // set up the texturing parameters
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
}