mode7 style tilemap X11+GL (require a 32x32 ./sprite.bmp)

main.c

//c99 main.c -o ../main -lX11 -lGL -lGLU && cd .. && ./main
#include <stdio.h>
#include <stdlib.h>
#include <X11/X.h>
#include <GL/gl.h>
#include <GL/glx.h>

GLuint texture[1];
int initGL(GLfloat width,GLfloat height){
	typedef uint8_t Sprite[32*32*3];
	Sprite pixels[2];
	FILE*f=fopen("sprite.bmp","rb");
	fseek(f,122,SEEK_SET);
	fread(pixels,1,sizeof(pixels),f);
	fclose(f);
	
	glGenTextures(1, &texture[0]);
	glBindTexture(GL_TEXTURE_2D, texture[0]);
	glTexImage2D(GL_TEXTURE_2D, 0, 3, 32, 64, 0, GL_BGR, GL_UNSIGNED_BYTE, pixels);
	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);

	glEnable(GL_TEXTURE_2D);
	glShadeModel(GL_SMOOTH);
	glClearColor(0.0f, 0.0f, 0.0f, 0.5f);
	glClearDepth(1.0f);
	glEnable(GL_DEPTH_TEST);
	glDepthFunc(GL_LEQUAL);
	glHint(GL_PERSPECTIVE_CORRECTION_HINT, GL_NICEST);
	
	GLfloat ratio = (GLfloat)width / (GLfloat)height;
	glViewport(0, 0, (GLint)width, (GLint)height);
	glMatrixMode(GL_PROJECTION);
	glLoadIdentity();
	GLdouble fH = 0.06854;//tan(fovY/360*pi)*zNear;
	GLdouble fW = fH * ratio;
	glFrustum( -fW, fW, -fH, fH, 0.1f, 100.0f );
	glMatrixMode(GL_MODELVIEW);
	glLoadIdentity();
	return 1;
}

GLfloat xpos=.0,ypos=.0,zpos=-3.,xrot=.0,yrot=.0,zrot=.0;
int drawGLScene(GLvoid){
	glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
	glLoadIdentity();
	glTranslatef(xpos, ypos, zpos);
	glRotatef(xrot*10,0,1,0);
	glBindTexture(GL_TEXTURE_2D, texture[0]);
	glBegin(GL_QUADS);
	typedef struct{float tx,ty,vx,vy,vz;}Node;
	Node nodes[2][4]={{
		{0, 0,-.5,-.5, .5},
		{1, 0, .5,-.5, .5},
		{1,.5, .5,-.5,-.5},
		{0,.5,-.5,-.5,-.5},
	},{
		{0,.5,-.5,-.5, .5},
		{1,.5, .5,-.5, .5},
		{1, 1, .5,-.5,-.5},
		{0, 1,-.5,-.5,-.5},
	}};
	int tex[]={
		1,1,1,1,
		1,0,0,1,
		1,0,0,1,
		1,1,1,1,
	};
	for(int i=0;i<16;i++){
		for(Node*n=nodes[tex[i]];n<nodes[tex[i]]+(sizeof(nodes[tex[i]])/sizeof(**nodes));n++){
			glTexCoord2f(n->tx, n->ty),glVertex3f(n->vx+(i%4), n->vy, n->vz+(i/4));
		}
	}
	glEnd();
	return(1);
}

int main(int argc, char *argv[]) {
#define SCREEN_WIDTH  640
#define SCREEN_HEIGHT 480
	Display*dpy = XOpenDisplay(NULL);
	Window root = DefaultRootWindow(dpy);
	XVisualInfo*vi = glXChooseVisual(dpy, 0, (GLint[]){GLX_RGBA, GLX_DEPTH_SIZE, 24, GLX_DOUBLEBUFFER, None});
	XSetWindowAttributes swa={
		.colormap = XCreateColormap(dpy, root, vi->visual, AllocNone),
		.event_mask = ExposureMask | KeyPressMask
	};
	Window win = XCreateWindow(dpy, root, 0, 0, SCREEN_WIDTH, SCREEN_HEIGHT, 0, vi->depth, InputOutput, vi->visual, CWColormap | CWEventMask, &swa);
	XMapWindow(dpy, win);
	GLXContext glc = glXCreateContext(dpy, vi, NULL, GL_TRUE);
	glXMakeCurrent(dpy, win, glc);
	initGL(SCREEN_WIDTH,SCREEN_HEIGHT);
	while(1){
		XEvent xev;
		if(XCheckWindowEvent(dpy, win, KeyPressMask, &xev)){
			if(xev.type == KeyPress){
				if(xev.xkey.keycode==9)break;
				if(xev.xkey.keycode>=110 && xev.xkey.keycode<=117)
					*((GLfloat*[]){&xrot,&zpos,&ypos,&xpos,&xpos,&xrot,&zpos,&ypos}[xev.xkey.keycode-110])+=xev.xkey.keycode&1?.1f:-.1f;
				else
					printf("unk code %i\n",xev.xkey.keycode);
				printf("pos<%.2f %.2f %.2f> rot<%.2f %.2f %.2f>\n",xpos,ypos,zpos,xrot,yrot,zrot);
			}else if(xev.type == Expose){
				XWindowAttributes gwa;
				XGetWindowAttributes(dpy, win, &gwa);
			}
		}
		drawGLScene();
		glXSwapBuffers(dpy, win);
	}
	glXMakeCurrent(dpy, None, NULL);
	glXDestroyContext(dpy, glc);
	XDestroyWindow(dpy, win);
	XCloseDisplay(dpy);
	return 0;
}