opengl4_texture.cpp

#include <glad/glad.h>
#include <GLFW/glfw3.h>
#include <iostream>
#include <math.h>
#include "shader.h"
#define STB_IMAGE_IMPLEMENTATION
#include "stb_image.h"
#define PI 3.1415927
void framebuffer_size_callback(GLFWwindow* window, int width, int height) {
	glViewport(0, 0, width, height);
}
void processInput(GLFWwindow* window) {
	if (glfwGetKey(window, GLFW_KEY_ESCAPE) == GLFW_PRESS) {
		glfwSetWindowShouldClose(window, true);
	}
}
int main() {
	glfwInit();
	glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 3);
	glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 3);
	glfwWindowHint(GLFW_OPENGL_PROFILE, GLFW_OPENGL_CORE_PROFILE);
	GLFWwindow* window = glfwCreateWindow(800, 600, "shader", NULL, NULL); 
	glfwMakeContextCurrent(window);
	gladLoadGLLoader((GLADloadproc)glfwGetProcAddress);
	glViewport(0, 0, 800, 600);
	glfwSetFramebufferSizeCallback(window, framebuffer_size_callback);
	float vertices[] = { 0.5,-0.5,0,
						1.0f,0.0f,0.0f,
						0.0f,0.0f,
						0.5,0.5,0,
					    0.0f,1.0f,0.0f,
						1.0f,0.0f,
						-0.5,0.5,0,
						0.0f,0.0f,1.0f, 
						0.5f,1.0f };
	unsigned int VBO;
	glGenBuffers(1, &VBO);
	glBindBuffer(GL_ARRAY_BUFFER, VBO);
	glBufferData(GL_ARRAY_BUFFER, sizeof(vertices), vertices, GL_STREAM_DRAW);
	
	Shader ourShader("VertexShader4.txt", "FragmentShader4.txt");
	unsigned int VAO;
	glGenVertexArrays(1, &VAO);
	glBindVertexArray(VAO);
	glBindBuffer(GL_ARRAY_BUFFER, VBO);
	glBufferData(GL_ARRAY_BUFFER, sizeof(vertices), vertices, GL_STREAM_DRAW);
	glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 8 * sizeof(float), (void*)0);
	glEnableVertexAttribArray(0);
	glVertexAttribPointer(1, 3, GL_FLOAT, GL_FALSE, 8 * sizeof(float), (void*)(3 * sizeof(float)));
	glEnableVertexAttribArray(1);
	glVertexAttribPointer(2, 2, GL_FLOAT, GL_FALSE, 8 * sizeof(float), (void*)(6 * sizeof(float)));
	glEnableVertexAttribArray(2);
	
	unsigned int texture1;
	glGenTextures(1, &texture1);
	glBindTexture(GL_TEXTURE_2D, texture1);
	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_MIRRORED_REPEAT);
	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_MIRRORED_REPEAT);
	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
	float borderColor[] = { 1.0f,1.0f,0.0f,1.0f };
	glTexParameterfv(GL_TEXTURE_2D, GL_TEXTURE_BORDER_COLOR, borderColor);
	int width, height, nrChannels;
	unsigned char* data = stbi_load("ketton.bmp", &width, &height, &nrChannels, 0);
	if (data) {
		glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB, width, height, 0, GL_RGB, GL_UNSIGNED_BYTE, data);
		glGenerateMipmap(GL_TEXTURE_2D);
	}
	else {
		std::cout << "读取纹理失败" << std::endl;
	}
	stbi_image_free(data);
	unsigned int texture2;
	glGenTextures(1, &texture2);
	glBindTexture(GL_TEXTURE_2D, texture2);
	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_MIRRORED_REPEAT);
	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_MIRRORED_REPEAT);
	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);

	data = stbi_load("beadpack.bmp", &width, &height, &nrChannels, 0);
	if (data) {
		glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB, width, height, 0, GL_RGB, GL_UNSIGNED_BYTE, data);
		glGenerateMipmap(GL_TEXTURE_2D);
	}
	else {
		std::cout << "读取纹理失败" << std::endl;
	}
	stbi_image_free(data);
	glActiveTexture(GL_TEXTURE0);
	glBindTexture(GL_TEXTURE_2D, texture1);
	glActiveTexture(GL_TEXTURE1);
	glBindTexture(GL_TEXTURE_2D, texture2);
	glBindVertexArray(VAO);
	ourShader.use();
	glUniform1i(glGetUniformLocation(ourShader.ID, "texture1"), 0);
	ourShader.setInt("texture2", 1);
	stbi_set_flip_vertically_on_load(true);
	while (!glfwWindowShouldClose(window)) {
		processInput(window);
		glClearColor(0.2f, 0.3f, 0.3f, 1.0f);
		glClear(GL_COLOR_BUFFER_BIT);
		float timeValue = glfwGetTime();
		for (int i = 0; i < 3; i++) {
			vertices[i * 8] = 0.5 * cos(timeValue + i * 2 * PI / 3);
			vertices[i * 8 + 1] = 0.5 * sin(timeValue + i * 2 * PI / 3);
		}
		glBufferData(GL_ARRAY_BUFFER, sizeof(vertices), vertices, GL_STREAM_DRAW);
		glDrawArrays(GL_TRIANGLES, 0, 3);
		glfwSwapBuffers(window);
		glfwPollEvents();
	}
	
	glfwTerminate();
	return 0;
}