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/* platform.c
*
* Platform
*
*
*/
#include <SDL/SDL.h>
#include <SDL/SDL_image.h>
#include <GL/glew.h>
#include "platform.h"
/* few light arrays */
GLfloat fNoLight[] = { 0.0f, 0.0f, 0.0f, 0.0f };
GLfloat fLowLight[] = { 0.25f, 0.25f, 0.25f, 1.0f };
GLfloat fBrightLight[] = { 1.0f, 1.0f, 1.0f, 1.0f };
/* light values and coordinates */
GLfloat whiteLight[] = { 0.05f, 0.05f, 0.05f, 1.0f };
GLfloat sourceLight[] = { 0.75f, 0.75f, 0.75f, 1.0f };
GLfloat lightPos[] = { -10.f, 5.0f, 5.0f, 1.0f };
/* variables that should be already defined and declared for us by main program */
extern const unsigned int xres;
extern const unsigned int yres;
extern const unsigned int bpp;
extern const char *window_caption;
extern const char *window_icon_path;
void setup_opengl(void)
{
/* setup fog */
glEnable(GL_FOG);
glFogfv(GL_FOG_COLOR, fLowLight); /* set fog color to match background */
glFogf(GL_FOG_START, 4.0f);
glFogf(GL_FOG_END, 20.0f);
glFogi(GL_FOG_MODE, GL_LINEAR); /* fog equation */
glEnable(GL_DEPTH_TEST); /* hidden surface removal */
glFrontFace(GL_CCW); /* counter clock-wise polygons face out */
glEnable(GL_CULL_FACE); /* do not calculate inside of a pyramid */
/* setup and enable light 0 */
/* ambient RGBA intensity of the entire scene */
glLightModelfv(GL_LIGHT_MODEL_AMBIENT, whiteLight);
glLightfv(GL_LIGHT0, GL_AMBIENT, sourceLight);
glLightfv(GL_LIGHT0, GL_DIFFUSE, fBrightLight);
glLightfv(GL_LIGHT0, GL_SPECULAR, fBrightLight);
glLightfv(GL_LIGHT0, GL_POSITION, lightPos);
/* enable lighting */
glEnable(GL_LIGHTING);
glEnable(GL_LIGHT0);
/* enable color tracking */
glEnable(GL_COLOR_MATERIAL);
/* set Material properties to follow glColor values */
glColorMaterial(GL_FRONT, GL_AMBIENT_AND_DIFFUSE);
glMaterialfv(GL_FRONT, GL_SPECULAR, fBrightLight);
glMateriali(GL_FRONT, GL_SHININESS, 128);
/* turn on anti aliasing for points, lines, and polygons */
glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
glEnable(GL_BLEND);
glEnable(GL_POINT_SMOOTH);
glHint(GL_POINT_SMOOTH_HINT, GL_NICEST);
glEnable(GL_LINE_SMOOTH);
glHint(GL_LINE_SMOOTH_HINT, GL_NICEST);
/* screws up snowman */
//glEnable(GL_POLYGON_SMOOTH);
//glHint(GL_POLYGON_SMOOTH_HINT, GL_NICEST);
/* gray background */
glClearColor(0.5f, 0.5f, 0.5f, 1.0f);
/* original texture loading used to be here */
/* texture filtering, we modify default values since we don't have mipmaps */
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
/* how OpenGL combines the colors from texels with the color of the underlying
* geometry is controlled by the texture environment mode */
glTexEnvi(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_MODULATE);
/* once texture is loaded and enabled, it will applied to every primitive
* that specifies coordinates */
glEnable(GL_TEXTURE_2D);
/* multisampling for polygons, conflicts with anti-aliasing */
//glEnable(GL_MULTISAMPLE);
/* don't know about this, but why not */
glLightModeli(GL_LIGHT_MODEL_COLOR_CONTROL, GL_SEPARATE_SPECULAR_COLOR);
}
void setup_sdl(void)
{
SDL_Surface *screen;
if (SDL_Init(SDL_INIT_VIDEO | SDL_INIT_AUDIO) < 0 )
{
fprintf(stderr, "unable to init SDL: %s\n", SDL_GetError());
exit(-1);
}
atexit(SDL_Quit);
SDL_WM_SetCaption(window_caption, NULL);
SDL_WM_SetIcon(IMG_Load(window_icon_path), NULL);
SDL_GL_SetAttribute(SDL_GL_RED_SIZE, 8);
SDL_GL_SetAttribute(SDL_GL_GREEN_SIZE, 8);
SDL_GL_SetAttribute(SDL_GL_BLUE_SIZE, 8);
SDL_GL_SetAttribute(SDL_GL_ALPHA_SIZE, 8);
SDL_GL_SetAttribute(SDL_GL_DOUBLEBUFFER, 1);
SDL_GL_SetAttribute(SDL_GL_DEPTH_SIZE, 16);
if ((screen = SDL_SetVideoMode(xres, yres, bpp, SDL_OPENGL | SDL_RESIZABLE)) == NULL)
{
fprintf(stderr, "unable to set video mode: %s\n", SDL_GetError());
exit(-1);
}
SDL_EnableUNICODE(1);
/* SDL doesn't trigger off a ResizeEvent at startup, but as we need this
* for OpenGL, we do this ourselves */
SDL_Event resizeEvent;
resizeEvent.type = SDL_VIDEORESIZE;
resizeEvent.resize.w = xres;
resizeEvent.resize.h = yres;
SDL_PushEvent(&resizeEvent);
}
void setup_glew(void)
{
/* initalize glew */
GLenum glewerr = glewInit();
if (GLEW_OK != glewerr)
{
fprintf(stderr, "error: %s\n", glewGetErrorString(glewerr));
exit(-1);
}
else
fprintf(stdout, "status: using GLEW %s\n", glewGetString(GLEW_VERSION));
/* display OpenGL version */
GLint major;
GLint minor;
glGetIntegerv(GL_MAJOR_VERSION, &major);
glGetIntegerv(GL_MINOR_VERSION, &minor);
fprintf(stdout, "version: OpenGL %d.%d detected\n", major, minor);
}
inline void fps_control(const unsigned int startclock)
{
unsigned int deltaclock = SDL_GetTicks() - startclock;
if (deltaclock < 1000 / FRAMES_PER_SECOND)
SDL_Delay((1000 / FRAMES_PER_SECOND) - deltaclock);
#ifdef STAT_FPS
char buffer[30] = { 0 };
sprintf(buffer, "%s: %4d fps", window_caption,
1000 / (SDL_GetTicks() - startclock));
SDL_WM_SetCaption(buffer, NULL);
#endif
}
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