Source

gltut / Tut 05 Objects in Depth / DepthFighting.cpp

Jason McKesson 7187ac0 

Jason McKesson cc7015a 


Jason McKesson b741697 
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Jason McKesson cc7015a 
Jason McKesson da7c819 
Jason McKesson b741697 


Jason McKesson 74c4b9b 
Jason McKesson cc7015a 











































Jason McKesson 9e0f8fd 
Jason McKesson cc7015a 






Jason McKesson 7187ac0 

Jason McKesson cc7015a 



Jason McKesson 7187ac0 

Jason McKesson cc7015a 






















































Jason McKesson c689e4d 



Jason McKesson cc7015a 








Jason McKesson 8618f34 
Jason McKesson cc7015a 



Jason McKesson b741697 
Jason McKesson fb24a18 

Jason McKesson cc7015a 

Jason McKesson 7187ac0 
Jason McKesson cc7015a 





Jason McKesson b741697 

Jason McKesson 9e0f8fd 

Jason McKesson cc7015a 

Jason McKesson b741697 

Jason McKesson cc7015a 











Jason McKesson b741697 

Jason McKesson cc7015a 





Jason McKesson b741697 



































































Jason McKesson cc7015a 















Jason McKesson 7187ac0 
Jason McKesson cc7015a 









Jason McKesson b741697 
Jason McKesson 9e0f8fd 



Jason McKesson b741697 
Jason McKesson 9e0f8fd 

Jason McKesson fb24a18 
















































Jason McKesson cc7015a 
Jason McKesson fb24a18 

Jason McKesson b741697 
Jason McKesson cc7015a 

Jason McKesson f314aea 
#include <string>
#include <vector>
#include <map>
#include <stdio.h>
#include <math.h>
#include <string.h>
#include <iostream>
#include <fstream>
#include <sstream>
#include <glload/gl_3_3.h>
#include <GL/freeglut.h>
#include "../framework/framework.h"

#define ARRAY_COUNT( array ) (sizeof( array ) / (sizeof( array[0] ) * (sizeof( array ) != sizeof(void*) || sizeof( array[0] ) <= sizeof(void*))))

GLuint theProgram;

GLuint offsetUniform;
GLuint perspectiveMatrixUnif;

float perspectiveMatrix[16];
const float fFrustumScale = 1.0f;

void InitializeProgram()
{
	std::vector<GLuint> shaderList;

	shaderList.push_back(Framework::LoadShader(GL_VERTEX_SHADER, "Standard.vert"));
	shaderList.push_back(Framework::LoadShader(GL_FRAGMENT_SHADER, "Standard.frag"));

	theProgram = Framework::CreateProgram(shaderList);

	offsetUniform = glGetUniformLocation(theProgram, "offset");

	perspectiveMatrixUnif = glGetUniformLocation(theProgram, "perspectiveMatrix");

	float fzNear = 1.0f; float fzFar = 100000.0f;

	memset(perspectiveMatrix, 0, sizeof(float) * 16);

	perspectiveMatrix[0] = fFrustumScale;
	perspectiveMatrix[5] = fFrustumScale;
	perspectiveMatrix[10] = (fzFar + fzNear) / (fzNear - fzFar);
	perspectiveMatrix[14] = (2 * fzFar * fzNear) / (fzNear - fzFar);
	perspectiveMatrix[11] = -1.0f;

	glUseProgram(theProgram);
	glUniformMatrix4fv(perspectiveMatrixUnif, 1, GL_FALSE, perspectiveMatrix);
	glUseProgram(0);
}

const int numberOfVertices = 8;

#define GREEN_COLOR 0.0f, 1.0f, 0.0f, 1.0f
#define BLUE_COLOR 	0.0f, 0.0f, 1.0f, 1.0f
#define RED_COLOR 1.0f, 0.0f, 0.0f, 1.0f

const float Z_OFFSET = 0.5f;

const float vertexData[] = {
	//Front face positions
	-400.0f,		 400.0f,			0.0f,
	400.0f,		 400.0f,			0.0f,
	400.0f,		-400.0f,			0.0f,
	-400.0f,		-400.0f,			0.0f,

	//Rear face positions
	-200.0f,		 600.0f,			-Z_OFFSET,
	600.0f,		 600.0f,			0.0f - Z_OFFSET,
	600.0f,		-200.0f,			0.0f - Z_OFFSET,
	-200.0f,		-200.0f,			-Z_OFFSET,

	//Front face colors.
	GREEN_COLOR,
	GREEN_COLOR,
	GREEN_COLOR,
	GREEN_COLOR,

	//Rear face colors.
	RED_COLOR,
	RED_COLOR,
	RED_COLOR,
	RED_COLOR,
};

const GLshort indexData[] =
{
	0, 1, 3,
	1, 2, 3,

	4, 5, 7,
	5, 6, 7,
};

GLuint vertexBufferObject;
GLuint indexBufferObject;
GLuint vao;


void InitializeVertexBuffer()
{
	glGenBuffers(1, &vertexBufferObject);

	glBindBuffer(GL_ARRAY_BUFFER, vertexBufferObject);
	glBufferData(GL_ARRAY_BUFFER, sizeof(vertexData), vertexData, GL_STATIC_DRAW);
	glBindBuffer(GL_ARRAY_BUFFER, 0);

	glGenBuffers(1, &indexBufferObject);

	glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, indexBufferObject);
	glBufferData(GL_ELEMENT_ARRAY_BUFFER, sizeof(indexData), indexData, GL_STATIC_DRAW);
	glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, 0);
}

//Called after the window and OpenGL are initialized. Called exactly once, before the main loop.
void init()
{
	InitializeProgram();
	InitializeVertexBuffer();

	glGenVertexArrays(1, &vao);
	glBindVertexArray(vao);

	size_t colorDataOffset = sizeof(float) * 3 * numberOfVertices;
	glBindBuffer(GL_ARRAY_BUFFER, vertexBufferObject);
	glEnableVertexAttribArray(0);
	glEnableVertexAttribArray(1);
	glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 0, 0);
	glVertexAttribPointer(1, 4, GL_FLOAT, GL_FALSE, 0, (void*)colorDataOffset);
	glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, indexBufferObject);

	glBindVertexArray(0);

	glEnable(GL_CULL_FACE);
	glCullFace(GL_BACK);
	glFrontFace(GL_CW);

	glEnable(GL_DEPTH_TEST);
	glDepthMask(GL_TRUE);
	glDepthFunc(GL_LEQUAL);
	glDepthRange(0.0f, 1.0f);
}

float fStart = 2534.0f;
float fDelta = 0.0f;

float CalcZOFfset()
{
	const float fLoopDuration = 5.0f;
	const float fScale = 3.14159f * 2.0f / fLoopDuration;

	float fElapsedTime = glutGet(GLUT_ELAPSED_TIME) / 1000.0f;

	float fCurrTimeThroughLoop = fmodf(fElapsedTime, fLoopDuration);

	//float fRet = cosf(fCurrTimeThroughLoop * fScale) * 500.0f - fStart;
	float fRet = fDelta - fStart;

	return fRet;
}

volatile bool bReadBuffer = false;

//Called to update the display.
//You should call glutSwapBuffers after all of your rendering to display what you rendered.
//If you need continuous updates of the screen, call glutPostRedisplay() at the end of the function.
void display()
{
	glClearColor(0.0f, 0.0f, 0.0f, 0.0f);
	glClearDepth(1.0f);
	glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

	glUseProgram(theProgram);
	glBindVertexArray(vao);

	float fZOffset = CalcZOFfset();
	glUniform3f(offsetUniform, 0.0f, 0.0f, fZOffset);
	glDrawElements(GL_TRIANGLES, ARRAY_COUNT(indexData), GL_UNSIGNED_SHORT, 0);

	glBindVertexArray(0);
	glUseProgram(0);

	glutSwapBuffers();

	//Read the backbuffer.
	if(bReadBuffer)
	{
		bReadBuffer = false;

		GLuint *pBuffer = new GLuint[500*500];
		glReadPixels(0, 0, 500, 500, GL_DEPTH_STENCIL, GL_UNSIGNED_INT_24_8, pBuffer);

		GLuint error = glGetError();

		std::string strOutput;
		strOutput.reserve(500*500*2 + (500));

		std::map<GLuint, char> charMap;

		GLuint *pBufferLoc = pBuffer;
		for(int y = 0; y < 500; y++)
		{
			for(int x = 0; x < 500; x++)
			{
				GLuint iValue = *pBufferLoc >> 8;
				iValue = iValue & 0x00FFFFFF;

				if(charMap.find(iValue) == charMap.end())
				{
					if(charMap.size())
						charMap[iValue] = static_cast<char>(65 + charMap.size() - 1);
					else
						charMap[iValue] = '.';
				}

				strOutput.push_back(charMap[iValue]);
				strOutput.push_back(' ');

				++pBufferLoc;
			}

			strOutput.push_back('\n');
		}

		delete[] pBuffer;

		{
			static int iFile = 0;
			std::ostringstream temp;
			temp << "test" << iFile << ".txt";
			std::string strFilename = temp.str();

			std::ofstream shaderFile(strFilename.c_str());
			shaderFile << "Offset: " << fZOffset << std::endl;
			for(std::map<GLuint, char>::const_iterator startIt = charMap.begin();
				startIt != charMap.end();
				++startIt)
			{
				shaderFile << startIt->first << "->\'" << startIt->second << "\'" << std::endl;
			}

			shaderFile << strOutput;

			printf("finished\n");

			iFile++;
		}


//		printf(strOutput.c_str());
	}
}

//Called whenever the window is resized. The new window size is given, in pixels.
//This is an opportunity to call glViewport or glScissor to keep up with the change in size.
void reshape (int w, int h)
{
	perspectiveMatrix[0] = fFrustumScale * (h / (float)w);
	perspectiveMatrix[5] = fFrustumScale;

	glUseProgram(theProgram);
	glUniformMatrix4fv(perspectiveMatrixUnif, 1, GL_FALSE, perspectiveMatrix);
	glUseProgram(0);

	glViewport(0, 0, (GLsizei) w, (GLsizei) h);
}


//Called whenever a key on the keyboard was pressed.
//The key is given by the ''key'' parameter, which is in ASCII.
//It's often a good idea to have the escape key (ASCII value 27) call glutLeaveMainLoop() to 
//exit the program.
void keyboard(unsigned char key, int x, int y)
{
	switch (key)
	{
	case 27:
		glutLeaveMainLoop();
		return;
	case 32:
		{
			float fValue = CalcZOFfset();
			printf("%f\n", fValue);
			bReadBuffer = true;
		}
		break;
		//Hundreds
	case 0x51:	//q
	case 0x71:
		fDelta += 100.0f;
		break;
	case 0x41:	//a
	case 0x61:
		fDelta -= 100.0f;
		break;

		//Tens
	case 0x57:	//w
	case 0x77:
		fDelta += 10.0f;
		break;
	case 0x53:	//s
	case 0x73:
		fDelta -= 10.0f;
		break;

		//Ones
	case 0x45:	//e
	case 0x65:
		fDelta += 1.0f;
		break;
	case 0x44:	//d	
	case 0x64:
		fDelta -= 1.0f;
		break;

		//Tenths
	case 0x52:	//r
	case 0x72:
		fDelta += 0.1f;
		break;
	case 0x46:	//f
	case 0x66:
		fDelta -= 0.1f;
		break;

		//Hundreths
	case 0x54:	//t
	case 0x74:
		fDelta += 0.01f;
		break;
	case 0x47:	//g
	case 0x67:
		fDelta -= 0.01f;
		break;
	}

	printf("%f\n", fDelta);
	glutPostRedisplay();
}

unsigned int defaults(unsigned int displayMode, int &width, int &height) {return displayMode;}
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