[C++] [OpenGL] 帧缓冲2

这个应该是多重渲染目标（MRT）吧，反正就这么命名了
r,g,b,d依次是red,green,blue,depth（其实是距离）
除100是因为太亮了，很容易就会达到1，而100是我视体的远平面
话说纹理竟然是反的

#version 330 core

in vec3 v_position;
in vec3 v_normal;
in vec3 v_normal2;
in vec2 v_texCoord;

layout(location = 0)out vec4 o_red;
layout(location = 1)out vec4 o_green;
layout(location = 2)out vec4 o_blue;
layout(location = 3)out vec4 o_depth;

uniform vec3 u_cameraposition;
uniform sampler2D s_sampler;

vec4 lighting()
{
	vec3 light_direction = normalize(v_position - u_cameraposition);
	vec3 view_direction = normalize(v_position - u_cameraposition);

	float ambient = 0.1;

	float diffuse = max(dot(v_normal, -light_direction), 0.0);
	float diffuse2 = max(dot(v_normal2, -light_direction), 0.0);

	vec3 reflect_direction = reflect(light_direction, v_normal);
	float specular = pow(max(dot(-view_direction, reflect_direction), 0.0), 32.0);
	vec3 reflect_direction2 = reflect(light_direction, v_normal2);
	float specular2 = pow(max(dot(-view_direction, reflect_direction2), 0.0), 32.0);

	return (ambient + diffuse + specular + diffuse2 + specular2) * texture(s_sampler,v_texCoord);
}

void main()
{
	vec4 finalColor = lighting();
	vec3 distance = (v_position - u_cameraposition) / 100.0;
	
	o_red = vec4(finalColor.r,0.0,0.0,1.0);
	o_green = vec4(0.0,finalColor.g,0.0,1.0);
	o_blue = vec4(0.0,0.0,finalColor.b,1.0);
	o_depth = vec4(distance.x,distance.y,distance.z,1.0);
}

初始化帧缓冲
p.s.其实我觉得RBO不需要

	GLFWmonitor* monitor = glfwGetPrimaryMonitor();
	const GLFWvidmode* videomode = glfwGetVideoMode(monitor);
	int width = videomode->width;
	int height = videomode->height;

	GLuint fbo;
	GLuint rbo;
	GLuint r_texture, g_texture, b_texture, d_texture;

	glGenFramebuffers(1, &fbo);
	glBindFramebuffer(GL_FRAMEBUFFER, fbo);

	glGenRenderbuffers(1, &rbo);
	glBindRenderbuffer(GL_RENDERBUFFER, rbo);
	glRenderbufferStorage(GL_RENDERBUFFER, GL_DEPTH24_STENCIL8, width, height);
	glBindRenderbuffer(GL_RENDERBUFFER, 0);

	glGenTextures(1, &r_texture);
	glBindTexture(GL_TEXTURE_2D, r_texture);
	glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB, width, height, 0, GL_RGB, GL_UNSIGNED_BYTE, nullptr);
	glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
	glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
	glBindTexture(GL_TEXTURE_2D, 0);

	glGenTextures(1, &g_texture);
	glBindTexture(GL_TEXTURE_2D, g_texture);
	glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB, width, height, 0, GL_RGB, GL_UNSIGNED_BYTE, nullptr);
	glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
	glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
	glBindTexture(GL_TEXTURE_2D, 0);

	glGenTextures(1, &b_texture);
	glBindTexture(GL_TEXTURE_2D, b_texture);
	glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB, width, height, 0, GL_RGB, GL_UNSIGNED_BYTE, nullptr);
	glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
	glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
	glBindTexture(GL_TEXTURE_2D, 0);

	glGenTextures(1, &d_texture);
	glBindTexture(GL_TEXTURE_2D, d_texture);
	glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB, width, height, 0, GL_RGB, GL_UNSIGNED_BYTE, nullptr);
	glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
	glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
	glBindTexture(GL_TEXTURE_2D, 0);

	glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, r_texture, 0);
	glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT1, GL_TEXTURE_2D, g_texture, 0);
	glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT2, GL_TEXTURE_2D, b_texture, 0);
	glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT3, GL_TEXTURE_2D, d_texture, 0);

	GLuint attachments[4] = { GL_COLOR_ATTACHMENT0, GL_COLOR_ATTACHMENT1, GL_COLOR_ATTACHMENT2, GL_COLOR_ATTACHMENT3 };
	glDrawBuffers(4, attachments);
	glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_DEPTH_STENCIL_ATTACHMENT, GL_RENDERBUFFER, rbo);
	
	if (glCheckFramebufferStatus(GL_FRAMEBUFFER) != GL_FRAMEBUFFER_COMPLETE)
	{
		std::cout << "Framebuffer is not complete." << std::endl;
		return -1;
	}

	glBindFramebuffer(GL_FRAMEBUFFER, 0);

渲染代码

		glBindFramebuffer(GL_FRAMEBUFFER, fbo);
		glClearColor(0.1f, 0.1f, 0.1f, 1.0f);
		glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
		data->program_m.useProgram();
		data->program_m.setUniform("u_projection", data->camera.getProjectionMatrix());
		data->program_m.setUniform("u_view", data->camera.getViewMatrix());
		data->program_m.setUniform("u_cameraposition", data->camera.getPosition());
		glActiveTexture(GL_TEXTURE0);
		data->texture.bindTexture();
		data->model.render(data->program_m);

		glBindFramebuffer(GL_FRAMEBUFFER, 0);
		glClearColor(0.1f, 0.1f, 0.1f, 1.0f);
		glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
		data->program_t.useProgram();
		data->program_t.setUniform("u_projection", glm::mat4(1.0f));
		data->program_t.setUniform("u_view", glm::mat4(1.0f));
		data->program_t.setUniform("u_cameraposition", data->camera.getPosition());

		data->target.setPosition(target_pos_r);
		data->program_t.setUniform("u_model", data->target.getModelMatrix());
		glBindTexture(GL_TEXTURE_2D, r_texture);
		data->target.render(data->program_t);

		data->target.setPosition(target_pos_g);
		data->program_t.setUniform("u_model", data->target.getModelMatrix());
		glBindTexture(GL_TEXTURE_2D, g_texture);
		data->target.render(data->program_t);

		data->target.setPosition(target_pos_b);
		data->program_t.setUniform("u_model", data->target.getModelMatrix());
		glBindTexture(GL_TEXTURE_2D, b_texture);
		data->target.render(data->program_t);

		data->target.setPosition(target_pos_d);
		data->program_t.setUniform("u_model", data->target.getModelMatrix());
		glBindTexture(GL_TEXTURE_2D, d_texture);
		data->target.render(data->program_t);

		glBindTexture(GL_TEXTURE_2D, 0);

最后删除缓冲区

	glDeleteFramebuffers(1, &fbo);
	glDeleteRenderbuffers(1, &rbo);
	glDeleteTextures(1, &r_texture);
	glDeleteTextures(1, &g_texture);
	glDeleteTextures(1, &b_texture);
	glDeleteTextures(1, &d_texture);

懒得放图:)