shader/scene.cpp

#include "scene.h"
#include "ggl.h"
#include "utils.h"
#include "ground.h"

GLuint vbo, ebo;
GLuint program;
GLint positionLocation, modelMatrixLocation, viewMatrixLocation, projectionMatrixLocation, colorLocation;//���㡢ģ�;�������ͼ������ͶӰ������λ��
GLint texcoordLocation, textureLocation;//������������λ�á���ͼ����λ��
GLuint texture;
glm::mat4 modelMatrix, viewMatrix, projectionMatrix;
Ground ground;

void Init() {
	/*1.��ʼ��vbo��Ϊvbo��ֵ*/
	float data[] = {
		-0.2f,-0.2f,0.0f,1.0f,  1.0f,0.0f,0.0f,1.0f, 0.0f,0.0f,
		0.2f,-0.2f,0.0f,1.0f,  0.0f,1.0f,0.0f,1.0f, 1.0f,0.0f,
		0.0f,0.2f,0.0f,1.0f,  0.0f,0.0f,1.0f,1.0f, 0.5f,1.0f
	};
	glGenBuffers(1, &vbo);//����vbo
	glBindBuffer(GL_ARRAY_BUFFER, vbo);//��������Ҫ������vbo
	glBufferData(GL_ARRAY_BUFFER, sizeof(float) * 30, data, GL_STATIC_DRAW);//����cpu���ݵ�GPU
	glBindBuffer(GL_ARRAY_BUFFER, 0);//�رհ���

	/*1.2ʹ��vbo�����滭˳��*/
	unsigned short indexes[] = { 0,1,2 };
	glGenBuffers(1, &ebo);
	glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, ebo);
	glBufferData(GL_ELEMENT_ARRAY_BUFFER, sizeof(unsigned short) * 3, indexes, GL_STATIC_DRAW);
	glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, 0);

	/*2.����shader*/
	int fileSize = 0;
	unsigned char * shaderCode = LoadFileContent("Res/test.vs", fileSize); 
	GLuint vsShader = CompileShader(GL_VERTEX_SHADER, (char*)shaderCode);//���� vertex shader
	delete shaderCode;

	shaderCode = LoadFileContent("Res/test.fs", fileSize);
	GLuint fsShader = CompileShader(GL_FRAGMENT_SHADER, (char*)shaderCode);//���� fragment shader
	delete shaderCode;

	/*3.���� vertex shader �� fragment shader*/
	program = CreateProgram(vsShader, fsShader);
	glDeleteShader(vsShader);
	glDeleteShader(fsShader);

	/*4.��ȡ���㡢ģ�;�������ͼ������ͶӰ��������GPU�е�λ�ã�������λ�ú������ܶ������и�ֵ����*/
	/*
	attribute vec4 position;
	uniform mat4 ModelMatrix;
	uniform mat4 ViewMatrix;
	uniform mat4 ProjectionMatrix;
	*/
	positionLocation = glGetAttribLocation(program, "position");
	colorLocation = glGetAttribLocation(program, "color");
	texcoordLocation = glGetAttribLocation(program, "texcoord");

	modelMatrixLocation = glGetUniformLocation(program, "ModelMatrix");
	viewMatrixLocation = glGetUniformLocation(program, "ViewMatrix");
	projectionMatrixLocation = glGetUniformLocation(program, "ProjectionMatrix");
	textureLocation = glGetUniformLocation(program, "U_Texture");
	modelMatrix = glm::translate(0.0f, 0.0f, -0.6f);

	texture = CreateTexture2DFromBMP("Res/test.bmp");

	ground.Init();
}
void SetViewPortSize(float width, float height) {
	//5.1.����ͶӰ����
	projectionMatrix = glm::perspective(60.0f, width / height, 0.1f, 1000.0f);
}
void Draw() {
	float frameTime = GetFrameTime();
	glClearColor(0.1f, 0.4f, 0.6f, 1.0f);
	glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

	ground.Draw(viewMatrix, projectionMatrix);

	glUseProgram(program);

	/*5.2.��MVP������ֵ���Կ���*/
	glUniformMatrix4fv(modelMatrixLocation, 1, GL_FALSE, glm::value_ptr(modelMatrix));//����ģ�;���
	glUniformMatrix4fv(viewMatrixLocation, 1, GL_FALSE, glm::value_ptr(viewMatrix));
	glUniformMatrix4fv(projectionMatrixLocation, 1, GL_FALSE, glm::value_ptr(projectionMatrix));
	

	/*6.���û��Ƶ�����*/
	glBindTexture(GL_TEXTURE_2D, texture);
	glUniform1i(textureLocation, 0);//������ͼ
	glBindBuffer(GL_ARRAY_BUFFER, vbo);//����vbo������1�������õļ�����������
	glEnableVertexAttribArray(positionLocation);//���ö�������
	glVertexAttribPointer(positionLocation, 4, GL_FLOAT, GL_FALSE, sizeof(float) * 10, 0);//��vbo�����������붥������
	glEnableVertexAttribArray(colorLocation);//������ɫ����
	glVertexAttribPointer(colorLocation, 4, GL_FLOAT, GL_FALSE, sizeof(float) * 10, (void*)(sizeof(float) * 4));//��vbo��ɫ����������ɫ����
	glEnableVertexAttribArray(texcoordLocation);
	glVertexAttribPointer(texcoordLocation, 2, GL_FLOAT, GL_FALSE, sizeof(float) * 10, (void*)(sizeof(float) * 8));

	glBindBuffer(GL_ARRAY_BUFFER, 0);

	/*7.����*/
	//glDrawArrays(GL_TRIANGLES, 0, 3);//˳������
	glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, ebo);
	glDrawElements(GL_TRIANGLES, 3, GL_UNSIGNED_SHORT, 0);//����ebo˳������
	glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, 0);
	
	
	/*8.��������*/
	glUseProgram(0);
}