int setupTextureShader(GLuint &textureID, const mesh& object)
{
glewInit();
if(!glewIsSupported("GL_VERSION_2_0 GL_ARB_multitexture GL_EXT_framebuffer_object"))
{
fprintf(stderr, "Required OpenGL extensions missing\n");
return -1;
}
/* create texture */
glGenTextures(1, &textureID);
glActiveTexture(GL_TEXTURE0);
glBindTexture(GL_TEXTURE_2D, textureID);
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_NEAREST);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
/* load texture file */
int width, height, components;
unsigned char *data = stbi_load("static/uv_color_map.png",
&width, &height, &components, 0);
glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB, width, height, 0, GL_RGB,
GL_UNSIGNED_BYTE, data);
stbi_image_free(data);
/* load UV data from mesh */
std::vector<glm::vec2> texture_uvs = object.getTextureUVs();
unsigned int uvsize = texture_uvs.size();
unsigned int uvmem = 2*uvsize*sizeof(GLfloat);
GLfloat *uv_buffer_data = (GLfloat *)malloc(uvmem);
for(int i = 0; i < uvsize; i++)
{
uv_buffer_data[2*i] = texture_uvs.at(i).x;
uv_buffer_data[2*i + 1] = texture_uvs.at(i).y;
}
/* pass data to shader */
GLuint uvBuffer;
glGenBuffers(1, &uvBuffer);
glBindBuffer(GL_ARRAY_BUFFER, uvBuffer);
glBufferData(GL_ARRAY_BUFFER, uvmem, uv_buffer_data, GL_STATIC_DRAW);
glEnableVertexAttribArray(0);
glVertexAttribPointer(0, 2, GL_FLOAT, GL_FALSE, 0, (void*)0);
free(uv_buffer_data);
glm::ivec2 shaders = loadShaders("src/texture.vert", "src/texture.frag");
GLuint vertexShader = shaders.x;
GLuint fragmentShader = shaders.y;
/* create and link program */
int program = glCreateProgram();
glBindAttribLocation(program, 0, "vertexUV");
int loc = glGetUniformLocation(program, "texsampler");
glUniform1i(loc, 0);
glAttachShader(program, vertexShader);
glAttachShader(program, fragmentShader);
glLinkProgram(program);
GLint pstatus;
glGetProgramiv(program, GL_LINK_STATUS, &pstatus);
if(pstatus != GL_TRUE)
{
char log[2048];
int len;
glGetProgramInfoLog(program, 2048, (GLsizei*)&len, log);
fprintf(stderr, "%s", log);
glDeleteProgram(program);
return -1;
}
return program;
}
