标签：glewInit glm openGL float renderingProgram vec4 调用 vec3 GL
openGL系列文章目录
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文章目录
前言
OpenGL Extension Wrangler Library （GLEW） 是一个跨平台的开源 C/C++ 扩展加载库。GLEW 提供了高效的运行时机制，用于确定目标平台上支持哪些 OpenGL 扩展。OpenGL 核心和扩展功能在单个头文件中公开。GLEW已经在各种操作系统上进行了测试，包括Windows，Linux，Mac OS X，FreeBSD，Irix和Solaris。
一、glew官网
二、glew库初始化调用失败
1.引入库
#include "glew/glew.h"
#include "glfw/glfw3.h"
#include "glm/glm.hpp"
#include "glm/gtc/matrix_transform.hpp"
#include "glm/gtc/type_ptr.hpp"
#include "camera.h"
#include "Utils.h"
#include "Sphere.h"
#include "SOIL2/SOIL2.h"
#include <iostream>
#include <fstream>
#include <string>
using namespace std;
static const int screenWidth = 1920;
static const int screenHeight = 1080;
static const float pai = 3.1415926f;
float toRadians(float degrees) { return degrees * 2.f * pai / (float)360.f; }
static const int numVAOs = 1;
static const int numVBOs = 4;
float cameraX = 0, cameraY = 0, cameraZ = 0;
float sphereX = 0, sphereY = 0, sphereZ = 0;
float lightLocX = 0.f, lightLocY = 0.f, lightLocZ = 0.f; //全局光照光源位置
GLuint renderingProgram = 1;
GLuint vao[numVAOs] = { 0 };
GLuint vbo[numVBOs] = { 0 };
// variable allocation for display
GLuint mvLoc = 0, projLoc = 0, nLoc = 0;
//phong 光照
GLuint globalAmbLoc = 0, ambLoc = 0, diffLoc = 0, specLoc = 0, posLoc = 0, mAmbLoc = 0, mDiffLoc = 0, mSpecLoc = 0, mShinLoc = 0;
int width = 0, height = 0;
float aspect = 0.f;
//MVP 矩阵
glm::mat4 mMat(1.f), vMat(1.f), pMat(1.f), mvMat(1.f), invTrMat(1.f);
glm::vec3 currentLightPos(0.f, 0.f, 0.f);
float lightPos[3] = { 0.f };
float rotAmt = -2.5f;
Sphere mySphere(48);
int numSphereVertices = 0;
int numSphereIndices = 0;
GLuint moonNormalMap = 0;
GLuint moonTexture = 0;
// white light
float globalAmbient[4] = { 0.1f, 0.1f, 0.1f, 1.f };
float lightAmbient[4] = { 0.f, 0.f, 0.f, 1.f };
float lightDiffuse[4] = { 1.f, 1.f, 1.f, 1.f };
float lightSpecular[4] = { 1.f, 1.f, 1.f, 1.f };
// silver material
float* matAmb = Utils::silverAmbient();
float* matDiff = Utils::silverDiffuse();
float* matSpec = Utils::silverSpecular();
float matShin = Utils::silverShininess();
void setupVertices(void)
{
numSphereIndices = mySphere.getNumIndices();
vector<int> ind = mySphere.getIndices();
vector<glm::vec3> vert = mySphere.getVertices();
vector<glm::vec2> text = mySphere.getTexCoords();
vector<glm::vec3> norm = mySphere.getNormals();
vector<glm::vec3> tang = mySphere.getTangents();
vector<float> pValues;
vector<float> tValues;
vector<float> nValues;
vector<float> tanValues;
for (int i = 0; i < numSphereIndices; i++)
{
pValues.push_back(vert[ind[i]].x); //gl_element_array_buffer,顶点对应成索引
pValues.push_back(vert[ind[i]].y);
pValues.push_back(vert[ind[i]].z);
tValues.push_back(text[ind[i]].s);
tValues.push_back(text[ind[i]].t);
nValues.push_back(norm[ind[i]].x);
nValues.push_back(norm[ind[i]].y);
nValues.push_back(norm[ind[i]].z);
tanValues.push_back(tang[ind[i]].x);
tanValues.push_back(tang[ind[i]].y);
tanValues.push_back(tang[ind[i]].z);
}
glGenVertexArrays(numVAOs, vao);
glBindVertexArray(vao[0]);
glGenBuffers(numVBOs, vbo);
glBindBuffer(GL_ARRAY_BUFFER, vbo[0]);
glBufferData(GL_ARRAY_BUFFER, pValues.size() * sizeof(float), &pValues[0], GL_STATIC_DRAW);
glBindBuffer(GL_ARRAY_BUFFER, vbo[1]);
glBufferData(GL_ARRAY_BUFFER, tValues.size() * sizeof(float), &tValues[0], GL_STATIC_DRAW);
glBindBuffer(GL_ARRAY_BUFFER, vbo[2]);
glBufferData(GL_ARRAY_BUFFER, nValues.size() * sizeof(float), &nValues[0], GL_STATIC_DRAW);
glBindBuffer(GL_ARRAY_BUFFER, vbo[3]);
glBufferData(GL_ARRAY_BUFFER, tanValues.size() * sizeof(float), &tanValues[0], GL_STATIC_DRAW);
}
void initallLights(glm::mat4 vMatrix)
{
glm::vec3 transformed = glm::vec3(vMatrix * glm::vec4(currentLightPos, 1.f));
lightPos[0] = transformed.x;
lightPos[1] = transformed.y;
lightPos[2] = transformed.z;
// get the locations of the light and material fields in the shader
globalAmbLoc = glGetUniformLocation(renderingProgram, "globalAmbient");
ambLoc = glGetUniformLocation(renderingProgram, "light.ambient");
diffLoc = glGetUniformLocation(renderingProgram, "light.diffuse");
specLoc = glGetUniformLocation(renderingProgram, "light.specular");
posLoc = glGetUniformLocation(renderingProgram, "light.position");
mAmbLoc = glGetUniformLocation(renderingProgram, "material.ambient");
mDiffLoc = glGetUniformLocation(renderingProgram, "material.diffuse");
mSpecLoc = glGetUniformLocation(renderingProgram, "material.specular");
mShinLoc = glGetUniformLocation(renderingProgram, "material.shininess");
// set the uniform light and material values in the shader
glProgramUniform4fv(renderingProgram, globalAmbLoc, 1, globalAmbient);
glProgramUniform4fv(renderingProgram, ambLoc, 1, lightAmbient);
glProgramUniform4fv(renderingProgram, diffLoc, 1, lightDiffuse);
glProgramUniform4fv(renderingProgram, specLoc, 1, lightSpecular);
glProgramUniform3fv(renderingProgram, posLoc, 1, lightPos);
glProgramUniform4fv(renderingProgram, mAmbLoc, 1, matAmb);
glProgramUniform4fv(renderingProgram, mDiffLoc, 1, matDiff);
glProgramUniform4fv(renderingProgram, mSpecLoc, 1, matSpec);
glProgramUniform1f(renderingProgram, mShinLoc, matShin);
}
void init(GLFWwindow* window)
{
renderingProgram = Utils::createShaderProgram("vertShader.vert", "fragShader.frag");
cameraX = 0.f, cameraY = 0.f, cameraZ = 2.f;
sphereX = 0.f, sphereY = 0.f, sphereZ = -1.f;
lightLocX = 3.f, lightLocY = 2.f, lightLocZ = 3.f;
glfwGetFramebufferSize(window, &width, &height);
aspect = (float)width / (float)height;
pMat = glm::perspective(toRadians(45.f), aspect, 0.1f, 1000.f);
setupVertices();
moonTexture = Utils::loadTexture("moon.jpg");
moonNormalMap = Utils::loadTexture("moonNORMAL.jpg");
}
void display(GLFWwindow* window, double currentTime)
{
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
glClearColor(0.f, 0.2f, 0.8f, 1.f);
glUseProgram(renderingProgram);
mvLoc = glGetUniformLocation(renderingProgram, "mv_matrix");
projLoc = glGetUniformLocation(renderingProgram, "proj_matrix");
nLoc = glGetUniformLocation(renderingProgram, "norm_matrix");
vMat = glm::translate(glm::mat4(1.f), glm::vec3(-cameraX, -cameraY, -cameraZ)); //注意相机的Z方向，否则看不到物体
mMat = glm::translate(glm::mat4(1.f), glm::vec3(sphereX, sphereY, sphereZ));
mMat = glm::rotate(mMat, toRadians(45.f), glm::vec3(1.f, 0.f, 0.f));
mMat = glm::rotate(mMat, rotAmt, glm::vec3(0.f, 1.f, 0.f));
rotAmt += 0.002f;
mvMat = vMat * mMat;
invTrMat = glm::transpose(glm::inverse(mvMat));
currentLightPos = glm::vec3(lightLocX, lightLocY, lightLocZ);
initallLights(vMat);
glUniformMatrix4fv(mvLoc, 1, GL_FALSE, glm::value_ptr(mvMat));
glUniformMatrix4fv(projLoc, 1, GL_FALSE, glm::value_ptr(pMat));
glUniformMatrix4fv(nLoc, 1, GL_FALSE, glm::value_ptr(invTrMat));
glBindBuffer(GL_ARRAY_BUFFER, vbo[0]);
glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 0, 0);
glEnableVertexAttribArray(0);
glBindBuffer(GL_ARRAY_BUFFER, vbo[1]);
glVertexAttribPointer(1, 2, GL_FLOAT, GL_FALSE, 0, 0);
glEnableVertexAttribArray(1);
glBindBuffer(GL_ARRAY_BUFFER, vbo[2]);
glVertexAttribPointer(2, 3, GL_FLOAT, GL_FALSE, 0, 0);
glEnableVertexAttribArray(2);
glBindBuffer(GL_ARRAY_BUFFER, vbo[3]);
glVertexAttribPointer(3, 3, GL_FLOAT, GL_FALSE, 0, 0);
glEnableVertexAttribArray(3);
glActiveTexture(GL_TEXTURE0);
glBindTexture(GL_TEXTURE_2D, moonTexture);
glEnable(GL_CULL_FACE);
glFrontFace(GL_CCW);
glDrawArrays(GL_TRIANGLES, 0, numSphereVertices);
}
void window_size_callback(GLFWwindow* window, int newWidth, int newHeight)
{
glfwGetFramebufferSize(window, &width, &height);
glViewport(0, 0, width, height);
aspect = (float)width / (float)height;
pMat = glm::perspective(toRadians(45.f), aspect, 0.1f, 1000.f);
}
int main(int argc, char** argv)
{
int glfwState = glfwInit();
if (glfwState == GLFW_FALSE)
{
cout << "Initialize GLFW failed,invoke glfwInit()......Error file:" << __FILE__ << "......Error line:" << __LINE__ << endl;
glfwTerminate();
exit(EXIT_FAILURE);
}
glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 4);
glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 6);
glfwWindowHint(GLFW_OPENGL_CORE_PROFILE, GLFW_OPENGL_PROFILE);
glfwWindowHint(GLFW_RESIZABLE, GL_TRUE);
GLFWwindow* window = glfwCreateWindow(screenWidth, screenHeight, "Texture plus normal", nullptr, nullptr);
if (!window)
{
cout << "GLFW create window failed,invoke glfwCreateWindow()......Error file:" << __FILE__ << "......Error line:" << __LINE__ << endl;
glfwTerminate();
exit(EXIT_FAILURE);
}
glfwMakeContextCurrent(window);
glfwSetWindowSizeCallback(window, window_size_callback);
int glewState = glewInit();
if (GLEW_OK != glewState)
{
cout << "GLEW initialize failed, invoke glewInit()......Error file:" << __FILE__ << "......Error line:" << __LINE__ << endl;
glfwTerminate();
exit(EXIT_FAILURE);
}
glfwSwapInterval(1);
init(window);
while (!glfwWindowShouldClose(window))
{
display(window, glfwGetTime());
glfwSwapBuffers(window);
glfwPollEvents();
}
glfwDestroyWindow(window);
glfwTerminate();
exit(EXIT_SUCCESS);
return 0;
}
2.glew调用失败原因
确实glfw上下文：
glfwMakeContextCurrent(window);
着色器
1.顶点着色器
#version 460 core
layout(location = 0) in vec3 vertPos;
layout(location = 1) in vec2 texCoords;
layout(location = 2) in vec3 vertNormal;
layout(location = 3) in vec3 vertTangent;
out vec3 varyingLightDir;
out vec3 varyingLightPos;
out vec3 varyingVertPos;
out vec3 varyingNormal;
out vec3 varyingTangent;
out vec3 originalVertex;
out vec2 tc;
layout(binding = 0) uniform sampler2D s;
layout(binding = 1) uniform sampler2D t;
struct PositionalLight
{
vec4 ambient;
vec4 diffuse;
vec4 specular;
vec3 position;
};
struct Material
{
vec4 ambient;
vec4 diffuse;
vec4 specular;
float shininess;
};
uniform vec4 globalAmbient;
uniform PositionalLight light;
uniform Material material;
uniform mat4 mv_matrix;
uniform mat4 proj_matrix;
uniform mat4 norm_matrix;
void main(void)
{
varyingVertPos = vec3(mv_matrix * vec4(vertPos, 1.f)).xyz;
varyingLightDir = light.position - varyingVertPos;
tc = texCoords;
originalVertex = vertPos;
varyingNormal = vec3(norm_matrix * vec4(vertNormal, 1.f)).xyz;
varyingTangent = vec3(norm_matrix * vec4(vertTangent, 1.f)).xyz;
gl_Position = proj_matrix * mv_matrix * vec4(vertPos, 1.f);
}
2.片元着色器
#version 460 core
in vec3 varyingLightDir;
in vec3 varyingVertPos;
in vec3 varyingNormal;
in vec3 varyingTangent;
in vec3 originalVertex;
in vec2 tc;
out vec4 fragColor;
layout(binding = 0) uniform sampler2D s;
layout(binding = 1) uniform sampler2D t;
struct PositionalLight
{
vec4 ambient;
vec4 diffuse;
vec4 specular;
vec3 position;
};
struct Material
{
vec4 ambient;
vec4 diffuse;
vec4 specular;
float shininess;
};
uniform vec4 globalAmbient;
uniform PositionalLight light;
uniform Material material;
uniform mat4 mv_matrix;
uniform mat4 proj_matrix;
uniform mat4 norm_matrix;
vec3 calcNewNormal()
{
vec3 normal = normalize(varyingNormal);
vec3 tangent = normalize(varyingTangent);
tangent = normalize(tangent - dot(tangent, normal) * normal);
vec3 bitangent = cross(tangent, normal);
mat3 tbn = mat3(tangent, bitangent, normal);
vec3 retrivedNormal = texture(s, tc).xyz;
retrivedNormal = retrivedNormal * 2.f - 1.f;
vec3 newNormal = tbn * retrivedNormal;
newNormal = normalize(newNormal);
return newNormal;
}
void main(void)
{
// normalize the light, normal, and view vectors:
vec3 L = normalize(varyingLightDir);
vec3 V = normalize(-varyingVertPos);
vec3 N = calcNewNormal();
// get the angle between the light and surface normal:
float cosTheta = dot(L, N);
// compute light reflection vector, with respect N:
vec3 R = normalize(reflect(-L, N)); //以表面顶点为基准，入射光和反射光方向一致
// angle between the view vector and reflected light:
float cosPhi = dot(V, R);
vec4 texC = texture(t, tc);
// compute ADS contributions with surface texture image:
fragColor = globalAmbient + light.ambient * texC
+ light.diffuse * texC * max(cosTheta, 0.f)
+ light.specular *texC * pow(max(cosPhi, 0.f), material.shininess);
}
运行结果
标签：glewInit,glm,openGL,float,renderingProgram,vec4,调用,vec3,GL 来源： https://blog.csdn.net/web15185420056/article/details/123628110
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