...
DDS_TEXTURE* sample_texture = new DDS_TEXTURE();
bool do_flip = true;
load_dds_from_file("file/path/of/dds_file/sample.dds", &sample_texture, do_flip);
...in opengl the dds file can be used in the following way (if it's an compressed texture):
...
glCompressedTexImage2D(GL_TEXTURE_2D, 0, sample_texture->format, sample_texture->width sample_texture->height, 0, sample_texture->sz, sample_texture->pixels);
...using an uncompressed texture should be used in the following way:
...
glTexImage2D(GL_TEXTURE_2D, 0, sample_texture->channels, sample_texture->width, sample_texture->width, 0, sample_texture->format, GL_UNSIGNED_BYTE, sample_texture->pixels);
...be sure to delete the loaded dds file after loading it:
delete (sample_texture);used the following shaders for visualizing the result:
vertex shader:
#version 330 core
layout (location = 0) in vec3 aPos;
layout (location = 1) in vec3 aColor;
layout (location = 2) in vec2 aTexCoord;
out vec3 ourColor;
out vec2 TexCoord;
void main()
{
gl_Position = vec4(aPos, 1.0);
ourColor = aColor;
TexCoord = vec2(aTexCoord.x, aTexCoord.y);
}fragment shader:
#version 330 core
out vec4 FragColor;
in vec3 ourColor;
in vec2 TexCoord;
// texture sampler
uniform sampler2D texture1;
void main()
{
FragColor = texture(texture1, TexCoord);
}FULL OPENGL USAGE EXAMPLE (used GLFW and GLAD)
#include <GLFW/glfw3.h>
#include <iostream>
#include "Shader.h"
#include "dds_loader.h"
void framebuffer_size_callback( GLFWwindow* window, int width, int height );
void processInput( GLFWwindow *window );
// settings
const unsigned int SCR_WIDTH = 800;
const unsigned int SCR_HEIGHT = 600;
float lastX = SCR_WIDTH / 2.0f;
float lastY = SCR_HEIGHT / 2.0f;
bool firstMouse = true;
// timing
float deltaTime = 0.0f;
float lastFrame = 0.0f;
int main( ) {
// glfw: initialize and configure
// ------------------------------
glfwInit( );
glfwWindowHint( GLFW_CONTEXT_VERSION_MAJOR, 3 );
glfwWindowHint( GLFW_CONTEXT_VERSION_MINOR, 3 );
glfwWindowHint( GLFW_OPENGL_PROFILE, GLFW_OPENGL_CORE_PROFILE );
#ifdef __APPLE__
glfwWindowHint( GLFW_OPENGL_FORWARD_COMPAT, GL_TRUE ); // uncomment this statement to fix compilation on OS X
#endif
// glfw window creation
// --------------------
GLFWwindow* window = glfwCreateWindow( SCR_WIDTH, SCR_HEIGHT, "LearnOpenGL", NULL, NULL );
if ( window == NULL ) {
std::cout << "Failed to create GLFW window" << std::endl;
glfwTerminate( );
return -1;
}
glfwMakeContextCurrent( window );
glfwSetFramebufferSizeCallback( window, framebuffer_size_callback );
// tell GLFW to capture our mouse
glfwSetInputMode( window, GLFW_CURSOR, GLFW_CURSOR_DISABLED );
// glad: load all OpenGL function pointers
// ---------------------------------------
if ( !gladLoadGLLoader( ( GLADloadproc ) glfwGetProcAddress ) ) {
std::cout << "Failed to initialize GLAD" << std::endl;
return -1;
}
// build and compile shaders
// -------------------------
// NOTE: you have to write your own shader loading lib
Shader shader( "shaders/Shader.vert", "shaders/Shader.frag" );
// set up vertex data (and buffer(s)) and configure vertex attributes
// ------------------------------------------------------------------
float vertices[] = {
// positions // colors // texture coords
0.5f, 0.5f, 0.0f, 1.0f, 0.0f, 0.0f, 1.0f, 1.0f, // top right
0.5f, -0.5f, 0.0f, 0.0f, 1.0f, 0.0f, 1.0f, 0.0f, // bottom right
-0.5f, -0.5f, 0.0f, 0.0f, 0.0f, 1.0f, 0.0f, 0.0f, // bottom left
-0.5f, 0.5f, 0.0f, 1.0f, 1.0f, 0.0f, 0.0f, 1.0f // top left
};
unsigned int indices[] = {
0, 1, 3, // first triangle
1, 2, 3 // second triangle
};
unsigned int VBO, VAO, EBO;
glGenVertexArrays(1, &VAO);
glGenBuffers(1, &VBO);
glGenBuffers(1, &EBO);
glBindVertexArray(VAO);
glBindBuffer(GL_ARRAY_BUFFER, VBO);
glBufferData(GL_ARRAY_BUFFER, sizeof(vertices), vertices, GL_STATIC_DRAW);
glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, EBO);
glBufferData(GL_ELEMENT_ARRAY_BUFFER, sizeof(indices), indices, GL_STATIC_DRAW);
// position attribute
glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 8 * sizeof(float), (void*)0);
glEnableVertexAttribArray(0);
// color attribute
glVertexAttribPointer(1, 3, GL_FLOAT, GL_FALSE, 8 * sizeof(float), (void*)(3 * sizeof(float)));
glEnableVertexAttribArray(1);
// texture coord attribute
glVertexAttribPointer(2, 2, GL_FLOAT, GL_FALSE, 8 * sizeof(float), (void*)(6 * sizeof(float)));
glEnableVertexAttribArray(2);
// load and create a texture
// -------------------------
unsigned int texture;
glGenTextures(1, &texture);
glBindTexture(GL_TEXTURE_2D, texture); // all upcoming GL_TEXTURE_2D operations now have effect on this texture object
// set the texture wrapping parameters
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT); // set texture wrapping to GL_REPEAT (default wrapping method)
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);
// set texture filtering parameters
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
DDS_TEXTURE* sample_texture = new DDS_TEXTURE();
load_dds_from_file("assets/Shopsign_Bakery_BaseColor.dds", &sample_texture, true);
glCompressedTexImage2D(GL_TEXTURE_2D, 0, sample_texture->format, sample_texture->width, sample_texture->height, 0, sample_texture->sz, sample_texture->pixels);
delete (sample_texture);
// render loop
// -----------
while (!glfwWindowShouldClose(window)) {
// input
// -----
processInput(window);
// render
// ------
glClearColor(0.2f, 0.3f, 0.3f, 1.0f);
glClear(GL_COLOR_BUFFER_BIT);
// bind Texture
glBindTexture(GL_TEXTURE_2D, texture);
// render
shader.use();
glBindVertexArray(VAO);
glDrawElements(GL_TRIANGLES, 6, GL_UNSIGNED_INT, 0);
// glfw: swap buffers and poll IO events (keys pressed/released, mouse moved etc.)
// -------------------------------------------------------------------------------
glfwSwapBuffers(window);
glfwPollEvents();
}
// optional: de-allocate all resources once they've outlived their purpose:
// ------------------------------------------------------------------------
glDeleteVertexArrays(1, &VAO);
glDeleteBuffers(1, &VBO);
glDeleteBuffers(1, &EBO);
// glfw: terminate, clearing all previously allocated GLFW resources.
// ------------------------------------------------------------------
glfwTerminate();
return 0;
}
// process all input: query GLFW whether relevant keys are pressed/released this frame and react accordingly
// ---------------------------------------------------------------------------------------------------------
void processInput(GLFWwindow* window){
if (glfwGetKey(window, GLFW_KEY_ESCAPE) == GLFW_PRESS)
glfwSetWindowShouldClose(window, true);
}
// glfw: whenever the window size changed (by OS or user resize) this callback function executes
// ---------------------------------------------------------------------------------------------
void framebuffer_size_callback(GLFWwindow* window, int width, int height){
// make sure the viewport matches the new window dimensions; note that width and
// height will be significantly larger than specified on retina displays.
glViewport(0, 0, width, height);
}