texture-test.cpp

#include <stdlib.h>
#include <stdio.h>
#include <stdint.h>

#define STB_IMAGE_IMPLEMENTATION
#include "stb_image.h"

#include <GL/glut.h>


GLuint texture;

// load a texture from file using the stb_image library
uint32_t loadTexture(const char* filename) {
	int width, height, components;
	unsigned char* data = stbi_load(filename, &width, &height, &components, STBI_rgb);
	
	glPushAttrib(GL_TEXTURE_BIT);
	
	unsigned int id;
	glGenTextures(1, &id);
	glBindTexture(GL_TEXTURE_2D, id);
	//      glGenerateMipmap(GL_TEXTURE_2D);
	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_MIN_FILTER, GL_LINEAR);
	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
	glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB, width, height, 0, GL_RGB, GL_UNSIGNED_BYTE, data);
	
	glPopAttrib();
	
	
	return id;
}


void display(void)
{
	glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
	
	glEnable(GL_BLEND);
	glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
	
	glEnable(GL_TEXTURE_2D);
	glBindTexture(GL_TEXTURE_2D, texture);
	
	/*
	glBegin(GL_QUADS);
	glTexCoord2f(0, 0); glVertex2f(-1, -1);
	glTexCoord2f(1, 0); glVertex2f(1, -1);
	glTexCoord2f(1, 1); glVertex2f(1, 1);
	glTexCoord2f(0, 1); glVertex2f(-1, 1);
	glEnd();
	*/
	glBegin(GL_QUADS);
		glTexCoord2f(0, 0); glVertex2f(0,0);
		glTexCoord2f(1, 0); glVertex2f(0.5,0);
		glTexCoord2f(1, 1);glVertex2f(0.5,0.5);
		glTexCoord2f(0, 1);glVertex2f(0,0.5);
	glEnd();
	
	glutSwapBuffers();
}

int main(int argc, char **argv)
{
	glutInit(&argc, argv);
	glutInitDisplayMode(GLUT_RGB | GLUT_DOUBLE | GLUT_DEPTH);
	glutCreateWindow("Texture viewer");
	glutDisplayFunc(display);
	
	texture = loadTexture("metal-texture.jpg");
	if (!texture)  {
		printf("No texture created; exiting.\n");
		return EXIT_FAILURE;
	}
	
	glutMainLoop();
	
	return EXIT_SUCCESS;
}