nuclear@0: #include <stdio.h>
nuclear@0: #include <unistd.h>
nuclear@0: #include <string.h>
nuclear@0: #include <errno.h>
nuclear@0: #include "texture.h"
nuclear@0: #include "object.h"
nuclear@0: 
nuclear@0: static inline Color sample_image(const Image &img, float u, float v, Texture::WrapMode wrapping);
nuclear@0: 
nuclear@0: Texture::Texture()
nuclear@0: 	: sampling(SampleMode::nearest), wrapping(WrapMode::repeat)
nuclear@0: {
nuclear@0: }
nuclear@0: 
nuclear@0: Texture::~Texture() {}
nuclear@0: 
nuclear@0: void Texture::set_name(const char *name)
nuclear@0: {
nuclear@0: 	this->name = name;
nuclear@0: }
nuclear@0: 
nuclear@0: const char *Texture::get_name() const
nuclear@0: {
nuclear@0: 	return name.c_str();
nuclear@0: }
nuclear@0: 
nuclear@0: void Texture::set_sampling_mode(SampleMode mode)
nuclear@0: {
nuclear@0: 	sampling = mode;
nuclear@0: }
nuclear@0: 
nuclear@0: Texture::SampleMode Texture::get_sampling_mode() const
nuclear@0: {
nuclear@0: 	return sampling;
nuclear@0: }
nuclear@0: 
nuclear@0: void Texture::set_wrapping_mode(WrapMode mode)
nuclear@0: {
nuclear@0: 	wrapping = mode;
nuclear@0: }
nuclear@0: 
nuclear@0: Texture::WrapMode Texture::get_wrapping_mode() const
nuclear@0: {
nuclear@0: 	return wrapping;
nuclear@0: }
nuclear@0: 
nuclear@0: 
nuclear@0: Color Texture::sample(const HitPoint &hit) const
nuclear@0: {
nuclear@0: 	return sample(hit.texcoord.x, hit.texcoord.y, 0.0f);
nuclear@0: }
nuclear@0: 
nuclear@0: Image *Texture2D::get_image(int idx)
nuclear@0: {
nuclear@0: 	return &img;
nuclear@0: }
nuclear@0: 
nuclear@0: const Image *Texture2D::get_image(int idx) const
nuclear@0: {
nuclear@0: 	return &img;
nuclear@0: }
nuclear@0: 
nuclear@0: 
nuclear@0: bool Texture2D::load(const char *fname)
nuclear@0: {
nuclear@0: 	name = fname;
nuclear@0: 	return img.load(fname);
nuclear@0: }
nuclear@0: 
nuclear@0: Color Texture2D::sample(float u, float v, float w) const
nuclear@0: {
nuclear@0: 	return sample_image(img, u, v, wrapping);
nuclear@0: }
nuclear@0: 
nuclear@0: TextureCube::TextureCube()
nuclear@0: {
nuclear@0: 	wrapping = WrapMode::clamp;
nuclear@0: }
nuclear@0: 
nuclear@0: Image *TextureCube::get_image(int idx)
nuclear@0: {
nuclear@0: 	return &img[idx];
nuclear@0: }
nuclear@0: 
nuclear@0: const Image *TextureCube::get_image(int idx) const
nuclear@0: {
nuclear@0: 	return &img[idx];
nuclear@0: }
nuclear@0: 
nuclear@0: 
nuclear@0: bool TextureCube::load(const char *fname)
nuclear@0: {
nuclear@0: 	// assume it's a cubemap descriptor file (face path per line)
nuclear@0: 	FILE *fp;
nuclear@0: 	if(!(fp = fopen(fname, "r"))) {
nuclear@0: 		fprintf(stderr, "failed to open the cubemap descriptor %s: %s\n", fname, strerror(errno));
nuclear@0: 		return false;
nuclear@0: 	}
nuclear@0: 
nuclear@0: 	name = fname;
nuclear@0: 
nuclear@0: 	char *prefix = (char*)alloca(strlen(fname) + 1);
nuclear@0: 	strcpy(prefix, fname);
nuclear@0: 	char *ptr = strrchr(prefix, '/');
nuclear@0: 	if(!ptr) {
nuclear@0: 		ptr = prefix;
nuclear@0: 	}
nuclear@0: 	*ptr = 0;
nuclear@0: 
nuclear@0: 	int xsz = 0, ysz = 0;
nuclear@0: 
nuclear@0: 	// load the faces
nuclear@0: 	char buf[512];
nuclear@0: 	for(int i=0; i<6; i++) {
nuclear@0: 		if(!fgets(buf, sizeof buf, fp)) {
nuclear@0: 			fprintf(stderr, "invalid cubemap descriptor file: %s\n", fname);
nuclear@0: 			return false;
nuclear@0: 		}
nuclear@0: 		if(buf[strlen(buf) - 1] == '\n') {
nuclear@0: 			buf[strlen(buf) - 1] = 0;
nuclear@0: 		}
nuclear@0: 
nuclear@0: 		std::string path = std::string(prefix) + "/" + std::string(buf);
nuclear@0: 		if(!img[i].load(path.c_str())) {
nuclear@0: 			fprintf(stderr, "failed to load image: %s\n", path.c_str());
nuclear@0: 			fclose(fp);
nuclear@0: 			return false;
nuclear@0: 		}
nuclear@0: 
nuclear@0: 		if(i == 0) {
nuclear@0: 			xsz = img[i].xsz;
nuclear@0: 			ysz = img[i].ysz;
nuclear@0: 		} else {
nuclear@0: 			if(img[i].xsz != xsz || img[i].ysz != ysz) {
nuclear@0: 				fprintf(stderr, "cubemap %s face image %s size (%dx%d) doesn't match the previous faces (%dx%d)\n",
nuclear@0: 						fname, path.c_str(), img[i].xsz, img[i].ysz, xsz, ysz);
nuclear@0: 				fclose(fp);
nuclear@0: 				return false;
nuclear@0: 			}
nuclear@0: 		}
nuclear@0: 	}
nuclear@0: 	return true;
nuclear@0: }
nuclear@0: 
nuclear@0: Color TextureCube::sample(float u, float v, float w) const
nuclear@0: {
nuclear@0: 	int face;
nuclear@0: 	Vector2 uv;
nuclear@0: 
nuclear@0: 	float abs_u = fabs(u);
nuclear@0: 	float abs_v = fabs(v);
nuclear@0: 	float abs_w = fabs(w);
nuclear@0: 
nuclear@0: 	if(abs_u > abs_v && abs_u > abs_w) {
nuclear@0: 		if(u >= 0.0) {
nuclear@0: 			face = 0;
nuclear@0: 			uv.x = w / abs_u;
nuclear@0: 			uv.y = v / abs_u;
nuclear@0: 		} else {
nuclear@0: 			face = 1;
nuclear@0: 			uv.x = -w / abs_u;
nuclear@0: 			uv.y = v / abs_u;
nuclear@0: 		}
nuclear@0: 	} else if(abs_v > abs_w) {
nuclear@0: 		if(v >= 0.0) {
nuclear@0: 			face = 2;
nuclear@0: 			uv.x = u / abs_v;
nuclear@0: 			uv.y = w / abs_v;
nuclear@0: 		} else {
nuclear@0: 			face = 3;
nuclear@0: 			uv.x = u / abs_v;
nuclear@0: 			uv.y = -w / abs_v;
nuclear@0: 		}
nuclear@0: 	} else {
nuclear@0: 		if(w >= 0.0) {
nuclear@0: 			face = 5;
nuclear@0: 			uv.x = -u / abs_w;
nuclear@0: 			uv.y = v / abs_w;
nuclear@0: 		} else {
nuclear@0: 			face = 4;
nuclear@0: 			uv.x = u / abs_w;
nuclear@0: 			uv.y = v / abs_w;
nuclear@0: 		}
nuclear@0: 	}
nuclear@0: 
nuclear@0: 	return sample_image(img[face], uv.x * 0.5 + 0.5, uv.y * 0.5 + 0.5, wrapping);
nuclear@0: }
nuclear@0: 
nuclear@0: Color TextureCube::sample(const HitPoint &hit) const
nuclear@0: {
nuclear@0: 	return sample(hit.normal.x, hit.normal.y, hit.normal.z);
nuclear@0: }
nuclear@0: 
nuclear@0: Texture *load_texture(const char *fname)
nuclear@0: {
nuclear@0: 	if(access(fname, R_OK) == -1) {
nuclear@0: 		fprintf(stderr, "failed to load texture %s: %s\n", fname, strerror(errno));
nuclear@0: 		return 0;
nuclear@0: 	}
nuclear@0: 
nuclear@0: 	Texture2D *tex2d = new Texture2D;
nuclear@0: 	if(tex2d->load(fname)) {
nuclear@0: 		return tex2d;
nuclear@0: 	}
nuclear@0: 	delete tex2d;
nuclear@0: 
nuclear@0: 	TextureCube *texcube = new TextureCube;
nuclear@0: 	if(texcube->load(fname)) {
nuclear@0: 		return texcube;
nuclear@0: 	}
nuclear@0: 	delete texcube;
nuclear@0: 
nuclear@0: 	return 0;
nuclear@0: }
nuclear@0: 
nuclear@0: #define CLAMP(x, lo, hi)	((x) < (lo) ? (lo) : ((x) > (hi) ? (hi) : (x)))
nuclear@0: 
nuclear@0: static inline Color sample_image(const Image &img, float u, float v, Texture::WrapMode wrapping)
nuclear@0: {
nuclear@0: 	int x = (int)round(u * img.xsz);
nuclear@0: 	int y = (int)round((1.0 - v) * img.ysz);
nuclear@0: 
nuclear@0: 	if(wrapping == Texture::WrapMode::clamp) {
nuclear@0: 		x = CLAMP(x, 0, img.xsz - 1);
nuclear@0: 		y = CLAMP(y, 0, img.ysz - 1);
nuclear@0: 	} else {
nuclear@0: 		x %= img.xsz;
nuclear@0: 		y %= img.ysz;
nuclear@0: 
nuclear@0: 		if(x < 0)
nuclear@0: 			x += img.xsz;
nuclear@0: 		if(y < 0)
nuclear@0: 			y += img.ysz;
nuclear@0: 	}
nuclear@0: 
nuclear@0: 	return img.pixels[y * img.xsz + x];
nuclear@0: }