From 7b554099ac39caf1ff135615d5453135d5c3dab4 Mon Sep 17 00:00:00 2001
From: John Tsiombikas <nuclear@mutantstargoat.com>
Date: Fri, 3 Feb 2017 07:31:30 +0200
Subject: [PATCH] tile generator

---
 .gitignore               |    1 +
 tools/tilegen/Makefile   |   13 ++++
 tools/tilegen/src/main.c |  179 ++++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 193 insertions(+)
 create mode 100644 tools/tilegen/Makefile
 create mode 100644 tools/tilegen/src/main.c

diff --git a/.gitignore b/.gitignore
index 499a618..c85b0ea 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,2 +1,3 @@
 *.o
 *.swp
+tilegen
diff --git a/tools/tilegen/Makefile b/tools/tilegen/Makefile
new file mode 100644
index 0000000..84a1e68
--- /dev/null
+++ b/tools/tilegen/Makefile
@@ -0,0 +1,13 @@
+src = $(wildcard src/*.c)
+obj = $(src:.c=.o)
+bin = tilegen
+
+CFLAGS = -pedantic -Wall -g
+LDFLAGS = -lGL -lGLU -lglut
+
+$(bin): $(obj)
+	$(CC) -o $@ $(obj) $(LDFLAGS)
+
+.PHONY: clean
+clean:
+	rm -f $(obj) $(bin)
diff --git a/tools/tilegen/src/main.c b/tools/tilegen/src/main.c
new file mode 100644
index 0000000..5468d6c
--- /dev/null
+++ b/tools/tilegen/src/main.c
@@ -0,0 +1,179 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <GL/glut.h>
+#include <assert.h>
+
+struct vec3 {
+	float x, y, z;
+};
+
+void disp(void);
+void draw_field(int xcells, int ycells);
+void draw_tile(int col, int row, int xcells, int ycells);
+void set_view_matrix(int eye, float ipd);
+void set_proj_matrix(int eye, float ipd);
+void reshape(int x, int y);
+void keyb(unsigned char key, int x, int y);
+
+static int win_width = 320;
+static int win_height = 640;
+static float aspect;
+static int view = 0;
+static float eye_dist = 1.4;
+
+int main(int argc, char **argv)
+{
+	glutInit(&argc, argv);
+	glutInitDisplayMode(GLUT_RGB | GLUT_DOUBLE);
+	glutInitWindowSize(win_width, win_height);
+	glutCreateWindow("tilegen");
+
+	glutDisplayFunc(disp);
+	glutReshapeFunc(reshape);
+	glutKeyboardFunc(keyb);
+
+	glClearColor(0.05, 0.05, 0.05, 1);
+	glEnable(GL_CULL_FACE);
+	glShadeModel(GL_FLAT);
+
+	glutMainLoop();
+	return 0;
+}
+
+void disp(void)
+{
+	glClear(GL_COLOR_BUFFER_BIT);
+
+	glColorMask(1, 0, 0, 0);
+
+	set_proj_matrix(-1, eye_dist);
+	set_view_matrix(-1, eye_dist);
+	glTranslatef(0, 0, -1);
+
+	draw_field(10, 20);
+
+	glColorMask(0, 1, 1, 0);
+
+	set_proj_matrix(1, eye_dist);
+	set_view_matrix(1, eye_dist);
+	glTranslatef(0, 0, -1);
+
+	draw_field(10, 20);
+
+	glColorMask(1, 1, 1, 1);
+
+	glutSwapBuffers();
+	assert(glGetError() == GL_NO_ERROR);
+}
+
+void draw_field(int xcells, int ycells)
+{
+	int i, j;
+
+	for(i=0; i<ycells; i++) {
+		for(j=0; j<xcells; j++) {
+			draw_tile(j, i, xcells, ycells);
+		}
+	}
+
+	/*
+	glBegin(GL_LINES);
+	glColor3f(1, 0, 0);
+	glVertex2f(-100, 0);
+	glVertex2f(100, 0);
+	glColor3f(0, 1, 0);
+	glVertex2f(0, -100);
+	glVertex2f(0, 100);
+	glEnd();
+	*/
+}
+
+#define DX	0.4
+#define DZ	0.3
+
+static struct vec3 tileverts[] = {
+	{-1, -1, 0}, {1, -1, 0}, {1, 1, 0}, {-1, 1, 0},
+	{-1 + DX, -1 + DX, DZ}, {1 - DX, -1 + DX, DZ},
+	{1 - DX, 1 - DX, DZ}, {-1 + DX, 1 - DX, DZ}
+};
+static struct vec3 tilecol[] = {
+	{0.8, 0.8, 0.8},	/* left */
+	{0.2, 0.2, 0.2},	/* bottom */
+	{0.4, 0.4, 0.4},	/* right */
+	{1.0, 1.0, 1.0},	/* top */
+	{0.7, 0.7, 0.7},	/* front */
+	{0, 0, 0}, {0, 0, 0}, {0, 0, 0}
+};
+static uint16_t tileidx[] = { /* 3 +---------+ 2 */
+	4, 7, 3, 0,               /*   |\ 7   6 /|   */
+	5, 4, 0, 1,               /*   | +-----+ |   */
+	6, 5, 1, 2,               /*   | |     | |   */
+	7, 6, 2, 3,               /*   | +-----+ |   */
+	5, 6, 7, 4                /*   |/ 4   5 \|   */
+};                            /* 0 +---------+ 1 */
+
+void draw_tile(int col, int row, int xcells, int ycells)
+{
+	int ncells = xcells > ycells ? xcells : ycells;
+	float cellsz = 2.0 / ncells;
+
+	glPushMatrix();
+	glTranslatef((col - xcells / 2.0 + 0.5) * cellsz, (row - ycells / 2.0 + 0.5) * cellsz, 0);
+	glScalef(cellsz * 0.5, cellsz * 0.5, cellsz * 0.5);
+
+	glEnableClientState(GL_VERTEX_ARRAY);
+	glEnableClientState(GL_COLOR_ARRAY);
+	glVertexPointer(3, GL_FLOAT, 0, tileverts);
+	glColorPointer(3, GL_FLOAT, 0, tilecol);
+	glDrawElements(GL_QUADS, 20, GL_UNSIGNED_SHORT, tileidx);
+	glDisableClientState(GL_VERTEX_ARRAY);
+	glDisableClientState(GL_COLOR_ARRAY);
+
+	glPopMatrix();
+}
+
+void set_view_matrix(int eye, float ipd)
+{
+	const float offs[] = {0.5, 0.0, -0.5};
+
+	glMatrixMode(GL_MODELVIEW);
+	glLoadIdentity();
+	glTranslatef(offs[eye + 1] * ipd, 0, 0);
+}
+
+void set_proj_matrix(int eye, float ipd)
+{
+	const float offs[] = {1.0, 0.0, -1.0};
+	float vpsz = 0.5;
+
+	float right = aspect * vpsz;
+	float top = vpsz;
+	float shift = offs[eye + 1] * ipd * 0.25; /* 0.25 -> 0.5 * znear */
+
+	glMatrixMode(GL_PROJECTION);
+	glLoadIdentity();
+	glFrustum(-right + shift, right + shift, -top, top, 0.5, 500.0);
+}
+
+void reshape(int x, int y)
+{
+	win_width = x;
+	win_height = y;
+	aspect = (float)win_width / (float)win_height;
+	glViewport(0, 0, x, y);
+}
+
+void keyb(unsigned char key, int x, int y)
+{
+	switch(key) {
+	case 27:
+		exit(0);
+
+	case '1':
+	case '2':
+	case '3':
+		view = key - '2';
+		glutPostRedisplay();
+		break;
+	}
+}
-- 
1.7.10.4