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refactor: extract gfx functions

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ktyl 2023-08-06 15:49:59 +02:00
parent 37025fbb09
commit 4795d88b91
3 changed files with 103 additions and 105 deletions
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88
src/gfx.cpp
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@ -2,8 +2,52 @@
#include <iostream>
#include "glm/glm.hpp"
#include "glm/gtc/matrix_transform.hpp"
#include "io.hpp"
const int WIDTH = 640;
const int HEIGHT = 480;
const float ASPECT = (float)WIDTH / (float)HEIGHT;
// Initialize GLFW, OpenGL and GLEW, open a window and make it the current context.
// Returns 0 for success, and -1 for any failure.
// Failures are printed to STDERR.
int initGraphics(GLFWwindow** window, const std::string& title)
{
// Set up GLFW, OpenGL and GLEW.
if (!glfwInit())
{
std::cerr << "Failed to initialize GLFW" << std::endl;
return -1;
}
glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 3);
glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 3);
glfwWindowHint(GLFW_OPENGL_PROFILE, GLFW_OPENGL_CORE_PROFILE);
*window = glfwCreateWindow(WIDTH, HEIGHT, title.c_str(), NULL, NULL);
if (!window)
{
glfwTerminate();
std::cerr << "Failed to open window with GLFW" << std::endl;
return -1;
}
glfwMakeContextCurrent(*window);
glewExperimental = GL_TRUE;
if (glewInit() != GLEW_OK)
{
std::cerr << "Failed to initialize GLEW" << std::endl;
return -1;
}
glEnable(GL_DEPTH_TEST);
return 0;
}
GLuint compileShader(const std::string& shaderPath, GLenum shaderType)
{
GLuint shader;
@ -56,3 +100,47 @@ GLuint compileShaderProgram(const std::string& fragShaderPath)
return shaderProgram;
}
void updateProjectionMatrix(GLuint shaderProgram)
{
float left = -ASPECT, right = ASPECT, bottom = -1.0, top = 1.0, near = -1.0, far = 1.0;
glm::mat4 projection = glm::ortho(left, right, bottom, top, near, far);
GLint projectionLocation = getShaderUniformLocation(shaderProgram, "_Projection");
glUniformMatrix4fv(projectionLocation, 1, GL_FALSE, &projection[0][0]);
}
void updateModelMatrix(GLuint shaderProgram, float time)
{
constexpr float angle = glm::radians(10.0);
glm::vec3 axis = glm::vec3(0.0, 1.0, 0.0);
glm::mat4 model = glm::rotate(glm::mat4(1.0), angle * time, axis);
GLint modelLocation = getShaderUniformLocation(shaderProgram, "_Model");
glUniformMatrix4fv(modelLocation, 1, GL_FALSE, &model[0][0]);
}
void updateViewMatrix(GLuint shaderProgram)
{
glm::mat4 view = glm::mat4(1.0);
GLint viewLocation = getShaderUniformLocation(shaderProgram, "_View");
glUniformMatrix4fv(viewLocation, 1, GL_FALSE, &view[0][0]);
}
void updateModelViewProjectionMatrix(GLuint shaderProgram, float time)
{
// Calculate matrices
updateProjectionMatrix(shaderProgram);
updateModelMatrix(shaderProgram, time);
updateViewMatrix(shaderProgram);
}
GLint getShaderUniformLocation(GLuint shaderProgram, const std::string& uniformName)
{
GLint location = glGetUniformLocation(shaderProgram, uniformName.c_str());
if (location == -1)
{
std::cerr << "Could not find uniform: " << uniformName << std::endl;
return -1;
}
return location;
}

13
src/gfx.hpp
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@ -3,6 +3,19 @@
#include <string>
#include "GL/glew.h"
#include <GLFW/glfw3.h>
extern const int WIDTH;
extern const int HEIGHT;
extern const float ASPECT;
int initGraphics(GLFWwindow** window, const std::string& title);
GLuint compileShaderProgram(const std::string& fragShaderPath);
GLuint compileShader(const std::string& shaderPath, GLenum shaderType);
GLint getShaderUniformLocation(GLuint shaderProgram, const std::string& uniformName);
void updateProjectionMatrix(GLuint shaderProgram);
void updateModelMatrix(GLuint shaderProgram, float time);
void updateViewMatrix(GLuint shaderProgram);
void updateModelViewProjectionMatrix(GLuint shaderProgram, float time);

105
src/main.cpp
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@ -35,120 +35,17 @@
// cmake ..
// cmake --build .
#include "glm/glm.hpp"
#include "glm/gtc/matrix_transform.hpp"
#include <GL/glew.h>
#include <GLFW/glfw3.h>
#include <iostream>
#include <string>
#include "gfx.hpp"
#include "icosphere.hpp"
#include "orbit.hpp"
#include <cmath>
#include "astro/twoBodyMethods.hpp"
const int WIDTH = 640;
const int HEIGHT = 480;
const float ASPECT = (float)WIDTH / (float)HEIGHT;
// Initialize GLFW, OpenGL and GLEW, open a window and make it the current context.
// Returns 0 for success, and -1 for any failure.
// Failures are printed to STDERR.
int initGraphics(GLFWwindow** window)
{
// Set up GLFW, OpenGL and GLEW.
if (!glfwInit())
{
std::cerr << "Failed to initialize GLFW" << std::endl;
return -1;
}
glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 3);
glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 3);
glfwWindowHint(GLFW_OPENGL_PROFILE, GLFW_OPENGL_CORE_PROFILE);
*window = glfwCreateWindow(WIDTH, HEIGHT, "Hello Astro", NULL, NULL);
if (!window)
{
glfwTerminate();
std::cerr << "Failed to open window with GLFW" << std::endl;
return -1;
}
glfwMakeContextCurrent(*window);
glewExperimental = GL_TRUE;
if (glewInit() != GLEW_OK)
{
std::cerr << "Failed to initialize GLEW" << std::endl;
return -1;
}
glEnable(GL_DEPTH_TEST);
return 0;
}
GLint getShaderUniformLocation(GLuint shaderProgram, const std::string& uniformName)
{
GLint location = glGetUniformLocation(shaderProgram, uniformName.c_str());
if (location == -1)
{
std::cerr << "Could not find uniform: " << uniformName << std::endl;
return -1;
}
return location;
}
void updateProjectionMatrix(GLuint shaderProgram)
{
float left = -ASPECT, right = ASPECT, bottom = -1.0, top = 1.0, near = -1.0, far = 1.0;
glm::mat4 projection = glm::ortho(left, right, bottom, top, near, far);
GLint projectionLocation = getShaderUniformLocation(shaderProgram, "_Projection");
glUniformMatrix4fv(projectionLocation, 1, GL_FALSE, &projection[0][0]);
}
void updateModelMatrix(GLuint shaderProgram, float time)
{
constexpr float angle = glm::radians(10.0);
glm::vec3 axis = glm::vec3(0.0, 1.0, 0.0);
glm::mat4 model = glm::rotate(glm::mat4(1.0), angle * time, axis);
GLint modelLocation = getShaderUniformLocation(shaderProgram, "_Model");
glUniformMatrix4fv(modelLocation, 1, GL_FALSE, &model[0][0]);
}
void updateViewMatrix(GLuint shaderProgram)
{
glm::mat4 view = glm::mat4(1.0);
GLint viewLocation = getShaderUniformLocation(shaderProgram, "_View");
glUniformMatrix4fv(viewLocation, 1, GL_FALSE, &view[0][0]);
}
void updateModelViewProjectionMatrix(GLuint shaderProgram, float time)
{
// Calculate matrices
updateProjectionMatrix(shaderProgram);
updateModelMatrix(shaderProgram, time);
updateViewMatrix(shaderProgram);
}
int main()
{
// Calculate period of ISS orbit around the Earth
const float semiMajorAxis = 6738000;
const float gravitationalParameter = 3.986e14;
float period = astro::computeKeplerOrbitalPeriod(semiMajorAxis, gravitationalParameter);
period /= 60.0;
std::cout << period << std::endl;
glm::vec3 v(0.0, 1.0, 2.0);
std::cout << "(" << v.x << ", " << v.y << ", " << v.z << ")" << std::endl;
GLFWwindow* window = nullptr;
if (initGraphics(&window) != 0)
if (initGraphics(&window, "Hello Astro") != 0)
return -1;
GLuint litProgram = compileShaderProgram("./frag_lit.glsl");