SDL2 简明教程（五）：OpenGL 绘制
//
// Created by user on 2/22/23.
//
#if defined(__cplusplus)
extern "C" {
#endif
#define GL_GLEXT_PROTOTYPES
#include <>
#include <SDL_opengl.h>
#if defined(__cplusplus)
};
#endif
int main() {
SDL_Init(SDL_INIT_VIDEO);
SDL_GL_SetAttribute(SDL_GL_DOUBLEBUFFER, 1);
SDL_GL_SetAttribute(SDL_GL_ACCELERATED_VISUAL, 1);
SDL_GL_SetAttribute(SDL_GL_RED_SIZE, 8);
SDL_GL_SetAttribute(SDL_GL_GREEN_SIZE, 8);
SDL_GL_SetAttribute(SDL_GL_BLUE_SIZE, 8);
SDL_GL_SetAttribute(SDL_GL_ALPHA_SIZE, 8);
SDL_GL_SetAttribute(SDL_GL_DEPTH_SIZE, 24);
SDL_GL_SetAttribute(SDL_GL_STENCIL_SIZE, 8);
SDL_GL_SetAttribute(SDL_GL_CONTEXT_MAJOR_VERSION, 3);
SDL_GL_SetAttribute(SDL_GL_CONTEXT_MINOR_VERSION, 2);
SDL_GL_SetAttribute(SDL_GL_CONTEXT_PROFILE_MASK, SDL_GL_CONTEXT_PROFILE_CORE);
static const int width = 800;
static const int height = 600;
SDL_Window *window =
SDL_CreateWindow("", SDL_WINDOWPOS_CENTERED, SDL_WINDOWPOS_CENTERED,
width, height, SDL_WINDOW_OPENGL | SDL_WINDOW_ALLOW_HIGHDPI);
SDL_GLContext gl_context = SDL_GL_CreateContext(window);
SDL_GL_MakeCurrent(window, gl_context);
SDL_GL_SetSwapInterval(1); // Enable vsync
// opengl operations
// create shaders and program
// ....
// set up vertex data(and buffer(s)) and configure vertex attributes
float vertices[] = {
-0.5f, -0.5f, 0.0f, // left
0.5f, -0.5f, 0.0f, // right
0.0f, 0.5f, 0.0f, // top
};
GLuint VBO{0};
GLuint VAO{0};
glGenVertexArrays(1, &VAO);
glGenBuffers(1, &VBO);
// bind the vertex array object first, then bind and set vertex buffers
// and then configure vertex attributes
glBindVertexArray(VAO);
glBindBuffer(GL_ARRAY_BUFFER, VBO);
glBufferData(GL_ARRAY_BUFFER, sizeof(vertices), vertices, GL_STATIC_DRAW);
glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 3 * sizeof(float), (void *)0);
glEnableVertexAttribArray(0);
glBindBuffer(GL_ARRAY_BUFFER, 0);
glBindVertexArray(0);
bool done = false;
for (; !done;) {
SDL_Event event;
while (SDL_PollEvent(&event)) {
if (event.type == SDL_QUIT)
done = true;
if (event.type == SDL_WINDOWEVENT && event.window.event == SDL_WINDOWEVENT_CLOSE && event.window.windowID == SDL_GetWindowID(window))
done = true;
}
// render
// -----
glClearColor(0.2f, 0.3f, 0.3f, 1.0f);
glClear(GL_COLOR_BUFFER_BIT);
// draw out first triangle
glUseProgram(shaderProgram);
glBindVertexArray(VAO);
glDrawArrays(GL_TRIANGLES, 0, 3);
SDL_GL_SwapWindow(window);
SDL_Delay(1);
}
SDL_DestroyWindow(window);
SDL_Quit();
return 0;
}