#include <stdio.h>
#include <stdlib.h>
#include <GL/glut.h>
#include "main.h"

void error(const char *file, int line)
{
	fprintf(stderr, "%s %d\n", file, line);
	exit(1);
}

void init(void)
{
	glPixelStorei(GL_UNPACK_ALIGNMENT, 1);
	glClearColor(0.0, 0.0, 0.5, 1.0);
}

void grid(int x, int y, int w, int h, int m, int n)
{
	int i;

	glBegin(GL_LINES);
	for (i = 0; i <= n; ++i) {
		glVertex2d(x, 0.5 + y + i * h);
		glVertex2d(1.0 + x + m * w, 0.5 + y + i * h);
	}
	for (i = 0; i <= m; ++i) {
		glVertex2d(0.5 + x + i * w, y);
		glVertex2d(0.5 + x + i * w, 1.0 + y + n * h);
	}
	glEnd();
}

void rect(int x, int y, int w, int h)
{
	glBegin(GL_QUADS);
	glVertex2i(x, y);
	glVertex2i(x, y + h);
	glVertex2i(x + w, y + h);
	glVertex2i(x + w, y);
	glEnd();
}

static int row = 0;

void display(void)
{
	int i;
	const unsigned char *p;

	glClear(GL_COLOR_BUFFER_BIT);

	glColor3d(0.0, 1.0, 0.0);
	grid(0, 0, 16, 16, 16, 6);
	grid(0, 100, 16, 16, 16, 6);

	if (row) {
		glColor3d(0.7, 0.0, 0.0);
		rect((row - 0xa0) % 16 * 16 + 1, (row - 0xa0) / 16 * 16 + 1, 15, 15);
	}

	glColor3d(1.0, 1.0, 1.0);
	glRasterPos2i(16, 0);
	for (i = 0x21; i < 0x7f; ++i) {
		if (!(i & 0xf)) {
			glRasterPos2i(0, 16 * (i / 16 - 2));
		}
		glBitmap(7, 14, -1.0, 15.0, 16.0, 0.0, ascii(i));
	}
	if (row) {
		glRasterPos2i(16, 100);
		for (i = 0xa1; i < 0xff; ++i) {
			if (!(i & 0xf)) {
				glRasterPos2i(0, 100 + 16 * (i / 16 - 10));
			}
			if ((p = kanji(row, i)) != NULL) {
				glBitmap(14, 14, -1.0, 15.0, 16.0, 0.0, p);
			} else {
				unsigned char c = 0;
				glBitmap(1, 1, 0.0, 0.0, 16.0, 0.0, &c);
			}
		}
	}

	glFlush();
}

void mouse(int button, int state, int x, int y)
{
	if (button == GLUT_RIGHT_BUTTON && state == GLUT_UP) {
		exit(0);
	} else if (button == GLUT_LEFT_BUTTON && state == GLUT_DOWN) {
		x /= 16; y /= 16;
		if (x == 0 && y == 0) {
			row = 0;
			glutPostRedisplay();
		} else if (!(x == 15 && y == 5) && x < 16 && y < 6) {
			row = y * 16 + x + 0xa0;
			glutPostRedisplay();
		}
	}
}