OpenGL笔记十二之实现三角形在屏幕横向上往复运动的动画

OpenGL笔记十二之实现三角形在屏幕横向上往复运动的动画

—— 2024-07-14 晚上

bilibili赵新政老师的教程看后笔记

code review!

1.运行

2.vs

#version 330 core
layout (location = 0) in vec3 aPos;
layout (location = 1) in vec3 aColor;

uniform float time;
uniform float speed;

out vec3 color;

void main()
{
   float dx = 0.3;
   float offsetX = sin(time * speed)*dx;
   gl_Position = vec4(aPos.x + offsetX, aPos.y, aPos.z, 1.0);
   color = aColor;
}

3.fs

#version 330 core
out vec4 FragColor;

in vec3 color;

void main()
{
   FragColor = vec4(color, 1.0f);
}

4.main.cpp的关键部分

代码

void render() {
	//执行opengl画布清理操作
	GL_CALL(glClear(GL_COLOR_BUFFER_BIT));

	//1 绑定当前的program
	shader->begin();

	shader->setFloat("time", glfwGetTime());
	shader->setFloat("speed", 5.0);
	
	//2 绑定当前的vao
	GL_CALL(glBindVertexArray(vao));
	//3 发出绘制指令
	glDrawElements(GL_TRIANGLES, 3, GL_UNSIGNED_INT, 0);
	glBindVertexArray(0);
	shader->end();
}

int main() {
	if (!app->init(800, 600)) {
		return -1;
	}

	app->setResizeCallback(OnResize);
	app->setKeyBoardCallback(OnKey);

	//设置opengl视口以及清理颜色
	GL_CALL(glViewport(0, 0, 800, 600));
	GL_CALL(glClearColor(0.2f, 0.3f, 0.3f, 1.0f));

	prepareShader();
	prepareVAO();
	while (app->update()) {
		render();
	}

	app->destroy();

	return 0;
}