1.1 --- /dev/null	Thu Jan 01 00:00:00 1970 +0000
     1.2 +++ b/src/texture.cc	Sun Nov 09 13:03:36 2014 +0200
     1.3 @@ -0,0 +1,237 @@
     1.4 +#include <stdio.h>
     1.5 +#include <unistd.h>
     1.6 +#include <string.h>
     1.7 +#include <errno.h>
     1.8 +#include "texture.h"
     1.9 +#include "object.h"
    1.10 +
    1.11 +static inline Color sample_image(const Image &img, float u, float v, Texture::WrapMode wrapping);
    1.12 +
    1.13 +Texture::Texture()
    1.14 +	: sampling(SampleMode::nearest), wrapping(WrapMode::repeat)
    1.15 +{
    1.16 +}
    1.17 +
    1.18 +Texture::~Texture() {}
    1.19 +
    1.20 +void Texture::set_name(const char *name)
    1.21 +{
    1.22 +	this->name = name;
    1.23 +}
    1.24 +
    1.25 +const char *Texture::get_name() const
    1.26 +{
    1.27 +	return name.c_str();
    1.28 +}
    1.29 +
    1.30 +void Texture::set_sampling_mode(SampleMode mode)
    1.31 +{
    1.32 +	sampling = mode;
    1.33 +}
    1.34 +
    1.35 +Texture::SampleMode Texture::get_sampling_mode() const
    1.36 +{
    1.37 +	return sampling;
    1.38 +}
    1.39 +
    1.40 +void Texture::set_wrapping_mode(WrapMode mode)
    1.41 +{
    1.42 +	wrapping = mode;
    1.43 +}
    1.44 +
    1.45 +Texture::WrapMode Texture::get_wrapping_mode() const
    1.46 +{
    1.47 +	return wrapping;
    1.48 +}
    1.49 +
    1.50 +
    1.51 +Color Texture::sample(const HitPoint &hit) const
    1.52 +{
    1.53 +	return sample(hit.texcoord.x, hit.texcoord.y, 0.0f);
    1.54 +}
    1.55 +
    1.56 +Image *Texture2D::get_image(int idx)
    1.57 +{
    1.58 +	return &img;
    1.59 +}
    1.60 +
    1.61 +const Image *Texture2D::get_image(int idx) const
    1.62 +{
    1.63 +	return &img;
    1.64 +}
    1.65 +
    1.66 +
    1.67 +bool Texture2D::load(const char *fname)
    1.68 +{
    1.69 +	name = fname;
    1.70 +	return img.load(fname);
    1.71 +}
    1.72 +
    1.73 +Color Texture2D::sample(float u, float v, float w) const
    1.74 +{
    1.75 +	return sample_image(img, u, v, wrapping);
    1.76 +}
    1.77 +
    1.78 +TextureCube::TextureCube()
    1.79 +{
    1.80 +	wrapping = WrapMode::clamp;
    1.81 +}
    1.82 +
    1.83 +Image *TextureCube::get_image(int idx)
    1.84 +{
    1.85 +	return &img[idx];
    1.86 +}
    1.87 +
    1.88 +const Image *TextureCube::get_image(int idx) const
    1.89 +{
    1.90 +	return &img[idx];
    1.91 +}
    1.92 +
    1.93 +
    1.94 +bool TextureCube::load(const char *fname)
    1.95 +{
    1.96 +	// assume it's a cubemap descriptor file (face path per line)
    1.97 +	FILE *fp;
    1.98 +	if(!(fp = fopen(fname, "r"))) {
    1.99 +		fprintf(stderr, "failed to open the cubemap descriptor %s: %s\n", fname, strerror(errno));
   1.100 +		return false;
   1.101 +	}
   1.102 +
   1.103 +	name = fname;
   1.104 +
   1.105 +	char *prefix = (char*)alloca(strlen(fname) + 1);
   1.106 +	strcpy(prefix, fname);
   1.107 +	char *ptr = strrchr(prefix, '/');
   1.108 +	if(!ptr) {
   1.109 +		ptr = prefix;
   1.110 +	}
   1.111 +	*ptr = 0;
   1.112 +
   1.113 +	int xsz = 0, ysz = 0;
   1.114 +
   1.115 +	// load the faces
   1.116 +	char buf[512];
   1.117 +	for(int i=0; i<6; i++) {
   1.118 +		if(!fgets(buf, sizeof buf, fp)) {
   1.119 +			fprintf(stderr, "invalid cubemap descriptor file: %s\n", fname);
   1.120 +			return false;
   1.121 +		}
   1.122 +		if(buf[strlen(buf) - 1] == '\n') {
   1.123 +			buf[strlen(buf) - 1] = 0;
   1.124 +		}
   1.125 +
   1.126 +		std::string path = std::string(prefix) + "/" + std::string(buf);
   1.127 +		if(!img[i].load(path.c_str())) {
   1.128 +			fprintf(stderr, "failed to load image: %s\n", path.c_str());
   1.129 +			fclose(fp);
   1.130 +			return false;
   1.131 +		}
   1.132 +
   1.133 +		if(i == 0) {
   1.134 +			xsz = img[i].xsz;
   1.135 +			ysz = img[i].ysz;
   1.136 +		} else {
   1.137 +			if(img[i].xsz != xsz || img[i].ysz != ysz) {
   1.138 +				fprintf(stderr, "cubemap %s face image %s size (%dx%d) doesn't match the previous faces (%dx%d)\n",
   1.139 +						fname, path.c_str(), img[i].xsz, img[i].ysz, xsz, ysz);
   1.140 +				fclose(fp);
   1.141 +				return false;
   1.142 +			}
   1.143 +		}
   1.144 +	}
   1.145 +	return true;
   1.146 +}
   1.147 +
   1.148 +Color TextureCube::sample(float u, float v, float w) const
   1.149 +{
   1.150 +	int face;
   1.151 +	Vector2 uv;
   1.152 +
   1.153 +	float abs_u = fabs(u);
   1.154 +	float abs_v = fabs(v);
   1.155 +	float abs_w = fabs(w);
   1.156 +
   1.157 +	if(abs_u > abs_v && abs_u > abs_w) {
   1.158 +		if(u >= 0.0) {
   1.159 +			face = 0;
   1.160 +			uv.x = w / abs_u;
   1.161 +			uv.y = v / abs_u;
   1.162 +		} else {
   1.163 +			face = 1;
   1.164 +			uv.x = -w / abs_u;
   1.165 +			uv.y = v / abs_u;
   1.166 +		}
   1.167 +	} else if(abs_v > abs_w) {
   1.168 +		if(v >= 0.0) {
   1.169 +			face = 2;
   1.170 +			uv.x = u / abs_v;
   1.171 +			uv.y = w / abs_v;
   1.172 +		} else {
   1.173 +			face = 3;
   1.174 +			uv.x = u / abs_v;
   1.175 +			uv.y = -w / abs_v;
   1.176 +		}
   1.177 +	} else {
   1.178 +		if(w >= 0.0) {
   1.179 +			face = 5;
   1.180 +			uv.x = -u / abs_w;
   1.181 +			uv.y = v / abs_w;
   1.182 +		} else {
   1.183 +			face = 4;
   1.184 +			uv.x = u / abs_w;
   1.185 +			uv.y = v / abs_w;
   1.186 +		}
   1.187 +	}
   1.188 +
   1.189 +	return sample_image(img[face], uv.x * 0.5 + 0.5, uv.y * 0.5 + 0.5, wrapping);
   1.190 +}
   1.191 +
   1.192 +Color TextureCube::sample(const HitPoint &hit) const
   1.193 +{
   1.194 +	return sample(hit.normal.x, hit.normal.y, hit.normal.z);
   1.195 +}
   1.196 +
   1.197 +Texture *load_texture(const char *fname)
   1.198 +{
   1.199 +	if(access(fname, R_OK) == -1) {
   1.200 +		fprintf(stderr, "failed to load texture %s: %s\n", fname, strerror(errno));
   1.201 +		return 0;
   1.202 +	}
   1.203 +
   1.204 +	Texture2D *tex2d = new Texture2D;
   1.205 +	if(tex2d->load(fname)) {
   1.206 +		return tex2d;
   1.207 +	}
   1.208 +	delete tex2d;
   1.209 +
   1.210 +	TextureCube *texcube = new TextureCube;
   1.211 +	if(texcube->load(fname)) {
   1.212 +		return texcube;
   1.213 +	}
   1.214 +	delete texcube;
   1.215 +
   1.216 +	return 0;
   1.217 +}
   1.218 +
   1.219 +#define CLAMP(x, lo, hi)	((x) < (lo) ? (lo) : ((x) > (hi) ? (hi) : (x)))
   1.220 +
   1.221 +static inline Color sample_image(const Image &img, float u, float v, Texture::WrapMode wrapping)
   1.222 +{
   1.223 +	int x = (int)round(u * img.xsz);
   1.224 +	int y = (int)round((1.0 - v) * img.ysz);
   1.225 +
   1.226 +	if(wrapping == Texture::WrapMode::clamp) {
   1.227 +		x = CLAMP(x, 0, img.xsz - 1);
   1.228 +		y = CLAMP(y, 0, img.ysz - 1);
   1.229 +	} else {
   1.230 +		x %= img.xsz;
   1.231 +		y %= img.ysz;
   1.232 +
   1.233 +		if(x < 0)
   1.234 +			x += img.xsz;
   1.235 +		if(y < 0)
   1.236 +			y += img.ysz;
   1.237 +	}
   1.238 +
   1.239 +	return img.pixels[y * img.xsz + x];
   1.240 +}