#include <stdio.h> // Standard C/C++ Input-Output (NEW)
#include <windows.h> // Standard Header For MSWindows Applications
#include <gl/glut.h> // The GL Utility Toolkit (GLUT) Header
// The Following Directive Fixes The Problem With Extra Console Window
#pragma comment(linker, "/subsystem:\"windows\" /entry:\"mainCRTStartup\"")
#define TEXTURES_NUM 1 // We Have 1 Texture (NEW)
#define CUBE_TEX 0 // Our Cube Texture Index (NEW)
// A Structure For RGB Bitmaps
typedef struct _RGBIMG {
GLuint w; // Image's Width
GLuint h; // Image's Height
GLubyte* data; // Image's Data (Pixels)
} RGBIMG;
// Global Variables
bool g_gamemode; // GLUT GameMode ON/OFF
bool g_fullscreen; // Fullscreen Mode ON/OFF (When g_gamemode Is OFF)
GLfloat g_xrot = 0.0f; // X Rotation (NEW)
GLfloat g_yrot = 0.0f; // Y Rotation (NEW)
GLfloat g_zrot = 0.0f; // Z Rotation (NEW)
GLuint g_texid[TEXTURES_NUM]; // Our Textures' Id List (NEW)
// Loads A RGB Raw Image From A Disk File And Updates Our Image Reference
// Returns true On Success, False On Fail.
bool load_rgb_image(const char* file_name, int w, int h, RGBIMG* refimg)
{
GLuint sz; // Our Image's Data Field Length In Bytes
FILE* file; // The Image's File On Disk
long fsize; // File Size In Bytes
GLubyte* p; // Helper Pointer
// Update The Image's Fields
refimg->w = (GLuint) w;
refimg->h = (GLuint) h;
sz = (((3*refimg->w+3)>>2)<<2)*refimg->h;
refimg->data = new GLubyte [sz];
if (refimg->data == NULL) return false;
// Open The File And Read The Pixels
file = fopen(file_name , "rb");
if (!file) return false;
fseek(file, 0L, SEEK_END);
fsize = ftell(file);
if (fsize != (long)sz) {
fclose(file);
return false;
}
fseek(file, 0L, SEEK_SET);
p = refimg->data;
while (fsize > 0) {
fread(p, 1, 1, file);
p++;
fsize--;
}
fclose(file);
return true;
}
// Setup Our Textures. Returns true On Success, false On Fail
bool setup_textures()
{
RGBIMG img;
// Create The Textures' Id List
glGenTextures(TEXTURES_NUM, g_texid);
// Load The Image From A Disk File
if (!load_rgb_image("swirl_256x256.raw", 256, 256, &img)) return false;
// Typical Texture Generation Using Data From The Image
glBindTexture(GL_TEXTURE_2D, g_texid[CUBE_TEX]);
glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_MIN_FILTER,GL_LINEAR);
glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_MAG_FILTER,GL_LINEAR);
glTexImage2D(GL_TEXTURE_2D, 0, 3, img.w, img.h, 0, GL_RGB, GL_UNSIGNED_BYTE, img.data);
// Finished With Our Image, Free The Allocated Data
delete img.data;
return true;
}
// Our GL Specific Initializations. Returns true On Success, false On Fail.
bool init(void)
{
glShadeModel(GL_SMOOTH); // Enable Smooth Shading
glClearColor(0.0f, 0.0f, 0.0f, 0.5f); // Black Background
glClearDepth(1.0f); // Depth Buffer Setup
glEnable(GL_DEPTH_TEST); // Enables Depth Testing
glDepthFunc(GL_LEQUAL); // The Type Of Depth Testing To Do
if (!setup_textures()) return false;
glEnable(GL_TEXTURE_2D); // Enable Texture Mapping (NEW)
glPixelStorei(GL_UNPACK_ALIGNMENT, 1); // Pixel Storage Mode To Byte Alignment (NEW)
glEnable(GL_CULL_FACE); // Cull Polygons (NEW)
glHint(GL_PERSPECTIVE_CORRECTION_HINT, GL_NICEST);
return true;
}
// Our Rendering Is Done Here
void render(void)
{
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
glLoadIdentity();
glTranslatef(0.0f,0.0f,-5.0f);
glRotatef(g_xrot,1.0f,0.0f,0.0f);
glRotatef(g_yrot,0.0f,1.0f,0.0f);
glRotatef(g_zrot,0.0f,0.0f,1.0f);
// Say Here What Texture Do You Want To Use
glBindTexture(GL_TEXTURE_2D, g_texid[CUBE_TEX]);
glBegin(GL_QUADS);
// Front Face
glTexCoord2f(0.0f, 0.0f); glVertex3f(-1.0f, -1.0f, 1.0f);
glTexCoord2f(1.0f, 0.0f); glVertex3f( 1.0f, -1.0f, 1.0f);
glTexCoord2f(1.0f, 1.0f); glVertex3f( 1.0f, 1.0f, 1.0f);
glTexCoord2f(0.0f, 1.0f); glVertex3f(-1.0f, 1.0f, 1.0f);
// Back Face
glTexCoord2f(1.0f, 0.0f); glVertex3f(-1.0f, -1.0f, -1.0f);
glTexCoord2f(1.0f, 1.0f); glVertex3f(-1.0f, 1.0f, -1.0f);
glTexCoord2f(0.0f, 1.0f); glVertex3f( 1.0f, 1.0f, -1.0f);
glTexCoord2f(0.0f, 0.0f); glVertex3f( 1.0f, -1.0f, -1.0f);
// Top Face
glTexCoord2f(0.0f, 1.0f); glVertex3f(-1.0f, 1.0f, -1.0f);
glTexCoord2f(0.0f, 0.0f); glVertex3f(-1.0f, 1.0f, 1.0f);
glTexCoord2f(1.0f, 0.0f); glVertex3f( 1.0f, 1.0f, 1.0f);
glTexCoord2f(1.0f, 1.0f); glVertex3f( 1.0f, 1.0f, -1.0f);
// Bottom Face
glTexCoord2f(1.0f, 1.0f); glVertex3f(-1.0f, -1.0f, -1.0f);
glTexCoord2f(0.0f, 1.0f); glVertex3f( 1.0f, -1.0f, -1.0f);
glTexCoord2f(0.0f, 0.0f); glVertex3f( 1.0f, -1.0f, 1.0f);
glTexCoord2f(1.0f, 0.0f); glVertex3f(-1.0f, -1.0f, 1.0f);
// Right face
glTexCoord2f(1.0f, 0.0f); glVertex3f( 1.0f, -1.0f, -1.0f);
glTexCoord2f(1.0f, 1.0f); glVertex3f( 1.0f, 1.0f, -1.0f);
glTexCoord2f(0.0f, 1.0f); glVertex3f( 1.0f, 1.0f, 1.0f);
glTexCoord2f(0.0f, 0.0f); glVertex3f( 1.0f, -1.0f, 1.0f);
// Left Face
glTexCoord2f(0.0f, 0.0f); glVertex3f(-1.0f, -1.0f, -1.0f);
glTexCoord2f(1.0f, 0.0f); glVertex3f(-1.0f, -1.0f, 1.0f);
glTexCoord2f(1.0f, 1.0f); glVertex3f(-1.0f, 1.0f, 1.0f);
glTexCoord2f(0.0f, 1.0f); glVertex3f(-1.0f, 1.0f, -1.0f);
glEnd();
g_xrot += 0.3f;
g_yrot += 0.2f;
g_zrot += 0.4f;
// Swap The Buffers To Become Our Rendering Visible
glutSwapBuffers ( );
}
// Our Reshaping Handler (Required Even In Fullscreen-Only Modes)
void reshape(int w, int h)
{
glViewport(0, 0, w, h);
glMatrixMode(GL_PROJECTION); // Select The Projection Matrix
glLoadIdentity(); // Reset The Projection Matrix
// Calculate The Aspect Ratio And Set The Clipping Volume
if (h == 0) h = 1;
gluPerspective(80, (float)w/(float)h, 1.0, 5000.0);
glMatrixMode(GL_MODELVIEW); // Select The Modelview Matrix
glLoadIdentity(); // Reset The Modelview Matrix
}
// Our Keyboard Handler (Normal Keys)
void keyboard(unsigned char key, int x, int y)
{
switch (key) {
case 27: // When Escape Is Pressed...
exit(0); // Exit The Program
break; // Ready For Next Case
default: // Now Wrap It Up
break;
}
}
// Our Keyboard Handler For Special Keys (Like Arrow Keys And Function Keys)
void special_keys(int a_keys, int x, int y)
{
switch (a_keys) {
case GLUT_KEY_F1:
// We Can Switch Between Windowed Mode And Fullscreen Mode Only
if (!g_gamemode) {
g_fullscreen = !g_fullscreen; // Toggle g_fullscreen Flag
if (g_fullscreen) glutFullScreen(); // We Went In Fullscreen Mode
else glutReshapeWindow(500, 500); // We Went In Windowed Mode
}
break;
default:
break;
}
}
// Ask The User If He Wish To Enter GameMode Or Not
void ask_gamemode()
{
int answer;
// Use Windows MessageBox To Ask The User For Game Or Windowed Mode
answer = MessageBox(NULL, "Do you want to enter game mode?", "Question",
MB_ICONQUESTION | MB_YESNO);
g_gamemode = (answer == IDYES);
// If Not Game Mode Selected, Use Windowed Mode (User Can Change That With F1)
g_fullscreen = false;
}
// Main Function For Bringing It All Together.
int main(int argc, char** argv)
{
ask_gamemode(); // Ask For Fullscreen Mode
glutInit(&argc, argv); // GLUT Initializtion
glutInitDisplayMode(GLUT_DEPTH | GLUT_RGB | GLUT_DOUBLE); // (CHANGED)
if (g_gamemode) {
glutGameModeString("640x480:16"); // Select The 640x480 In 16bpp Mode
if (glutGameModeGet(GLUT_GAME_MODE_POSSIBLE))
glutEnterGameMode(); // Enter Full Screen
else g_gamemode = false; // Cannot Enter Game Mode, Switch To Windowed
}
if (!g_gamemode) {
glutInitWindowSize(500, 500); // Window Size If We Start In Windowed Mode
glutCreateWindow("NeHe's OpenGL Framework"); // Window Title
}
if (!init()) { // Our Initialization
MessageBox(NULL,"Cannot initialize textures.","Error",MB_ICONSTOP);
return -1;
}
glutDisplayFunc(render); // Register The Display Function
glutReshapeFunc(reshape); // Register The Reshape Handler
glutKeyboardFunc(keyboard); // Register The Keyboard Handler
glutSpecialFunc(special_keys); // Register Special Keys Handler
glutIdleFunc(render); // We Render In Idle Time
glutMainLoop(); // Go To GLUT Main Loop
return 0;
}
NeHe tutorial help (HELP BADLY NEEDED)
Author
Does anyone know how to edit the code for the NeHe tutorial (#6 Texture mapping) so that it loads .bmp files instead of .raw ones i posted the code for the NeHe tutorial below
/*
NeHe (nehe.gamedev.net) OpenGL tutorial series
GLUT port.in 2001 by milix (milix_gr@hotmail.com)
Most comments are from the original tutorials found in NeHe.
For VC++ users, create a Win32 Console project and link
the program with glut32.lib, glu32.lib, opengl32.lib
*/
[Edited by - voldemort62442 on May 26, 2008 8:55:41 PM]
Plz edit your post and either replace that source code with a link to the tutorial, or at least wrap it in [source] [/source] tags ;)
The easiest way to get support for other image formats (IMO) is to use a loading library like DevIL or SOIL.
The easiest way to get support for other image formats (IMO) is to use a loading library like DevIL or SOIL.
[edit] Ah, beaten to the punch. Ah well, this post may yet have merit, so I leave it here.
A note: my suggestion to the original question is a fairly simplistic one, I'd say - in general, the one that Hodgman gives is probably better. [/edit]
First of all, I suspect that posting pieces of code over a few lines' length might discourage potential respondents. Since the code already exists on the NeHe website, surely a link might have sufficed? If you do, either in this or another thread, want to post longer sections of code, however, I recommend placing it within [ source][ /source] tags (without the addition spaces within the tags, of course); source tags should also preserve indentation, thus potentially increasing legibility. The result should look something like this:
As to your request, a quick search of the site turned up this article in the results, perhaps it will be of use: How to Load a Bitmap. If not, try the search and ignore that result (which was the first when I searched, as I recall) - something else may prove useful.
A note: my suggestion to the original question is a fairly simplistic one, I'd say - in general, the one that Hodgman gives is probably better. [/edit]
First of all, I suspect that posting pieces of code over a few lines' length might discourage potential respondents. Since the code already exists on the NeHe website, surely a link might have sufficed? If you do, either in this or another thread, want to post longer sections of code, however, I recommend placing it within [ source][ /source] tags (without the addition spaces within the tags, of course); source tags should also preserve indentation, thus potentially increasing legibility. The result should look something like this:
//Code hereAs to your request, a quick search of the site turned up this article in the results, perhaps it will be of use: How to Load a Bitmap. If not, try the search and ignore that result (which was the first when I searched, as I recall) - something else may prove useful.
I use SDL_image to load my images. It supports .png, .bmp, .tga, and way more. I can't seems to locate any tutorials so just google SDL, SDL_image, or IMG_Load
The only difference i believe in loading a RAW is that a raw image is that it doesn't have any headers to worry about.
When you load a file such as TGA or a BMP i believe they have headers inside of them that contains information about the image. Here is some info, it will let you know what is in a BMP, which is literally a header and RBG info.
http://en.wikipedia.org/wiki/BMP_file_format
So really you only have to modify your RAW loader a little to compensate for some headers in the BMP file format.
For example here are a couple of searches in mine, written in c
For every file format that isn't compressed the same kind of rule applies, in TGA loaders though you will need to allow a bit in your data array to take in alpha values.
When you load a file such as TGA or a BMP i believe they have headers inside of them that contains information about the image. Here is some info, it will let you know what is in a BMP, which is literally a header and RBG info.
http://en.wikipedia.org/wiki/BMP_file_format
So really you only have to modify your RAW loader a little to compensate for some headers in the BMP file format.
For example here are a couple of searches in mine, written in c
/* seek through the bmp header, up to the width/height: */ fseek(file, 18, SEEK_CUR); /* seek past the rest of the bitmap header. */ fseek(file, 24, SEEK_CUR);For every file format that isn't compressed the same kind of rule applies, in TGA loaders though you will need to allow a bit in your data array to take in alpha values.
This topic is closed to new replies.
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