//global includes

#include <GL/glew.h>

#include <GL/gl.h>

#include "SDL.h"

//local includes

#include "globaldefs.h"

#include "sdlstuff.h" //todo something this

#include "shaderstuff.h"

#include "glstuff.h"

//local vars

GLuint texid2, texid1;

GLuint fbid2, fbid1;

GLuint fsvbo, fsivbo, fsvao;

int which = FALSE;

int count = 0;

float aspect = 0;

//float fsverts[] = {-1.0, -1.0, -0.5, 0.0, 0.0,

// 1.0, -1.0, -0.5, 1.0, 0.0,

// 1.0, 1.0, -0.5, 1.0, 1.0,

// -1.0, 1.0, -0.5, 0.0, 1.0};

float fsverts[] = {-1.0, -1.0, 0.0, 0.0,

1.0, -1.0, 1.0, 0.0,

1.0, 1.0, 1.0, 1.0,

-1.0, 1.0, 0.0, 1.0};

GLuint fsindices[] = {0,1,2, 2,3,0};

//functions

extern void glDrawScreen();

int initFB(void){

if(playwidth ==0) playwidth = 1;

if(playheight ==0) playheight = 1;

aspect = (float)screenWidth/(float)screenHeight;

glGenTextures(1, &texid1);

glBindTexture(GL_TEXTURE_2D, texid1);

//may need to change gl_int to byte or something fo speed

glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);

glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);

glTexImage2D(GL_TEXTURE_2D, 0, GL_RED, playwidth, playheight, 0, GL_RED, GL_UNSIGNED_BYTE, NULL);

glBindTexture(GL_TEXTURE_2D, 0);

glGenFramebuffers(1, &fbid1);

glBindFramebuffer(GL_FRAMEBUFFER, fbid1);

glFramebufferTexture2D(GL_FRAMEBUFFER,GL_COLOR_ATTACHMENT0,GL_TEXTURE_2D, texid1, 0);

glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

glBindFramebuffer(GL_FRAMEBUFFER, 0);//unbind

if(debugmode) printf("DEBUG -- Bound framebuffer1 to: %i and texture to : %i \n", fbid1, texid1);

glGenTextures(1, &texid2);

glBindTexture(GL_TEXTURE_2D, texid2);

//may need to change gl_int to byte or something fo speed

glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);

glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);

glTexImage2D(GL_TEXTURE_2D, 0, GL_RED, playwidth, playheight, 0, GL_RED, GL_UNSIGNED_BYTE, NULL);

glBindTexture(GL_TEXTURE_2D, 0);

glGenFramebuffers(1, &fbid2);

glBindFramebuffer(GL_FRAMEBUFFER, fbid2);

glFramebufferTexture2D(GL_FRAMEBUFFER,GL_COLOR_ATTACHMENT0,GL_TEXTURE_2D, texid2, 0);

glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

glBindFramebuffer(GL_FRAMEBUFFER, 0);//unbind

if(debugmode) printf("DEBUG -- Bound framebuffer2 to: %i and texture to : %i \n", fbid2, texid2);

//todo error detection

return TRUE;

}

int initVBO(void){

glGenVertexArrays(1, &fsvao);

glGenBuffers(1, &fsvbo);

glGenBuffers(1, &fsivbo);

glBindVertexArray(fsvao);

glBindBuffer(GL_ARRAY_BUFFER, fsvbo);

glBufferData(GL_ARRAY_BUFFER, sizeof(fsverts),fsverts, GL_STATIC_DRAW);

glEnableClientState(GL_VERTEX_ARRAY);

glVertexPointer(2, GL_FLOAT, 4*sizeof(GLfloat), NULL);

glEnableClientState(GL_TEXTURE_COORD_ARRAY);

glTexCoordPointer(2, GL_FLOAT, 4*sizeof(GLfloat), ((char*)NULL)+2*sizeof(GLfloat) );

glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, fsivbo);

glBufferData(GL_ELEMENT_ARRAY_BUFFER, sizeof(fsindices),fsindices, GL_STATIC_DRAW);

return TRUE;

}

int glInit(void){

if(debugmode) printf("DEBUG -- Initialising OpenGL \n");

GLenum glewError = glewInit();

if( glewError != GLEW_OK ){

printf( "Error initializing GLEW! %s\n", glewGetErrorString( glewError ) );

return FALSE;

}

glDisable(GL_DEPTH_TEST);

glClearColor(0.0f, 0.0f, 0.0f, 0.5f);

glEnable(GL_TEXTURE_2D);

//todo move this stuff

glViewport(0, 0, playwidth, playheight);

glMatrixMode(GL_PROJECTION);// Select The Projection Matrix

glLoadIdentity();// Reset The Projection Matrix

glOrtho(-1.0f, 1.0f, -1.0f, 1.0f, 0.1f, 100.0f); //maybe change

glMatrixMode(GL_MODELVIEW); // Select The Modelview Matrix

glLoadIdentity(); // Reset The Modelview Matrix

glColor3f(1.0f, 1.0f, 1.0f); //wont need this much longer

//todo error checkelecking

if(!initShader()) return FALSE;

if(!initFB()) return FALSE;

// glUseProgram(programobject);

initVBO();

return TRUE;

}

void drawfsquad(void){

/* glBegin(GL_QUADS);

glTexCoord2f(0.0f, 0.0f);glVertex3f(-1.0f,-1.0f, -0.5f);

glTexCoord2f(1.0f, 0.0f);glVertex3f( 1.0f,-1.0f, -0.5f);

glTexCoord2f(1.0f, 1.0f);glVertex3f( 1.0f, 1.0f, -0.5f);

glTexCoord2f(0.0f, 1.0f);glVertex3f(-1.0f, 1.0f, -0.5f);

glEnd();

*/

/*

glBegin(GL_QUADS);

glTexCoord2f(0.0f, 0.0f);glVertex2f(-1.0f,-1.0f);

glTexCoord2f(1.0f, 0.0f);glVertex2f( 1.0f,-1.0f);

glTexCoord2f(1.0f, 1.0f);glVertex2f( 1.0f, 1.0f);

glTexCoord2f(0.0f, 1.0f);glVertex2f(-1.0f, 1.0f);

glEnd();

*/

glDrawElements(GL_TRIANGLES, 6, GL_UNSIGNED_INT, 0);

}

void drawsmallquad(const float sizex, const float sizey){

glBegin(GL_QUADS);

glTexCoord2f(0.0f, 0.0f);glVertex3f(-sizex,-sizey, -0.5f);

glTexCoord2f(1.0f, 0.0f);glVertex3f( sizex,-sizey, -0.5f);

glTexCoord2f(1.0f, 1.0f);glVertex3f( sizex, sizey, -0.5f);

glTexCoord2f(0.0f, 1.0f);glVertex3f(-sizex, sizey, -0.5f);

glEnd();

}

void drawposquad(const float sizex, const float sizey, const float xpos, const float ypos){ //todo maybe calculate these when changes occour instead of every frame?

glBegin(GL_QUADS);

glTexCoord2f(0.0f, 0.0f);glVertex3f(xpos-sizex,ypos-sizey, -0.5f);

glTexCoord2f(1.0f, 0.0f);glVertex3f(xpos+sizex,ypos-sizey, -0.5f);

glTexCoord2f(1.0f, 1.0f);glVertex3f(xpos+sizex,ypos+sizey, -0.5f);

glTexCoord2f(0.0f, 1.0f);glVertex3f(xpos-sizex,ypos+sizey, -0.5f);

glEnd();

}

int loadTexture(const char * filename){

//todo make texture struct

void * data;

int width, height;

GLuint texture;

sdlImportImage(filename, &height, &width, &data);

glGenTextures(1, &texture);

glBindTexture(GL_TEXTURE_2D, texture);

glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB, width, height, 0, GL_BGR, GL_UNSIGNED_BYTE, data);

glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);

glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);

glBindFramebuffer(GL_FRAMEBUFFER,fbid2);

glBindTexture(GL_TEXTURE_2D, texture);

glUseProgram(0);

drawsmallquad((float)width/(float)playwidth, (float)height/(float)playheight); //i forgot the casting rules for int division

glDeleteTextures( 1, &texture);

glDrawScreen(FALSE);

glUseProgram(programobject);

return TRUE;

}

void startsmall(void){

glBindFramebuffer(GL_FRAMEBUFFER, fbid2);

glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

glColor3f(1.0f, 1.0f, 1.0f); //wont need this much longer

drawsmallquad(0.5f, 0.5f);

}

int glRender(void){

// glUseProgram(programobject);

if(which){ // this is a fraction of a fraction of a percent faster... theoretically

glBindFramebuffer(GL_FRAMEBUFFER,fbid2);

glBindTexture(GL_TEXTURE_2D, texid1);

// glFramebufferTexture2D(GL_FRAMEBUFFER,GL_COLOR_ATTACHMENT0,GL_TEXTURE_2D, texid2, 0);

} else {

glBindFramebuffer(GL_FRAMEBUFFER,fbid1);

glBindTexture(GL_TEXTURE_2D, texid2);

// glFramebufferTexture2D(GL_FRAMEBUFFER,GL_COLOR_ATTACHMENT0,GL_TEXTURE_2D, texid1, 0);

}

drawfsquad();

if(count > skip){

glDrawScreen(FALSE);

count = 0;

}

which = !which;

count++;

//todo errorcheckin

return TRUE;

}

void glDrawScreen(int redraw){

glViewport(0, 0, screenWidth, screenHeight);

glMatrixMode(GL_PROJECTION);// Select The Projection Matrix

glLoadIdentity();// Reset The Projection Matrix

glOrtho(-aspect, aspect, -1.0f, 1.0f, 0.1f, 100.0f); //maybe change

// glMatrixMode(GL_MODELVIEW); // Select The Modelview Matrix

// glLoadIdentity(); // Reset The Modelview Matrix

if(which)glBindTexture(GL_TEXTURE_2D, texid1);

else glBindTexture(GL_TEXTURE_2D, texid2);

glBindFramebuffer(GL_FRAMEBUFFER, 0);

glUseProgram(0);

if(redraw) glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

drawposquad(zoom, zoom, viewposx, viewposy);

// glBlitFramebuffer(0,0,1000,1000,0,0,1000,1000, GL_COLOR_BUFFER_BIT,GL_LINEAR);

//todo make this cleaner

SDL_GL_SwapBuffers();

glViewport(0, 0, playwidth, playheight);

glMatrixMode(GL_PROJECTION);// Select The Projection Matrix

glLoadIdentity();// Reset The Projection Matrix

glOrtho(-1.0f, 1.0f, -1.0f, 1.0f, 0.1f, 100.0f); //maybe change

// glMatrixMode(GL_MODELVIEW); // Select The Modelview Matrix

// glLoadIdentity(); // Reset The Modelview Matrix

glUseProgram(programobject);

}