texture_1d.cpp

#include "texture.h"
 
using namespace sgltk;
 
Texture_1d::Texture_1d() : Texture() {
    target = GL_TEXTURE_1D;
}
 
Texture_1d::Texture_1d(unsigned int res, GLenum internal_format, GLenum type, GLenum format) : Texture() {
    target = GL_TEXTURE_1D;
    create_empty(res, internal_format, type, format);
}
 
Texture_1d::Texture_1d(const Image& image) : Texture() {
    target = GL_TEXTURE_1D;
    load(image);
}
 
Texture_1d::Texture_1d(const std::string& path) : Texture() {
    target = GL_TEXTURE_1D;
    load(path);
}
 
Texture_1d::~Texture_1d() {
}
 
void Texture_1d::create_empty(unsigned int res,
                  GLenum internal_format,
                  GLenum type, GLenum format) {
    width = res;
    height = 1;
 
    bind();
    glTexImage1D(GL_TEXTURE_1D, 0,
             internal_format, res, 0, format, type, nullptr);
    glTexParameteri(GL_TEXTURE_1D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
    glTexParameteri(GL_TEXTURE_1D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
    glTexParameteri(GL_TEXTURE_1D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
    unbind();
}
 
bool Texture_1d::load(const std::string& path) {
    Image img;
    if(!img.load(path))
        return false;
 
    width = img.width;
    height = 1;
    return load(img);
}
 
bool Texture_1d::load(const Image& image) {
    if(!image.image)
        return false;
 
    SDL_Surface *tmp = SDL_ConvertSurfaceFormat(image.image,
        SDL_PIXELFORMAT_RGBA8888, 0);
    if(!tmp) {
        return false;
    }
 
    bind();
    glTexParameteri(GL_TEXTURE_1D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
    glTexParameteri(GL_TEXTURE_1D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
    glTexParameteri(GL_TEXTURE_1D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
    glTexImage1D(GL_TEXTURE_1D, 0, GL_RGBA, image.width, 0,
             GL_RGBA, GL_UNSIGNED_INT_8_8_8_8, tmp->pixels);
    glGenerateMipmap(GL_TEXTURE_1D);
    unbind();
    SDL_FreeSurface(tmp);
    return true;
}
 
void Texture_1d::bind(unsigned int texture_unit) {
    glActiveTexture(GL_TEXTURE0 + texture_unit);
    glBindTexture(GL_TEXTURE_1D, texture);
}
 
void Texture_1d::unbind(unsigned int texture_unit) {
    glActiveTexture(GL_TEXTURE0 + texture_unit);
    glBindTexture(GL_TEXTURE_1D, 0);
}