first sketch

1 files changed, 198 insertions, 0 deletions

diff --git a/gragl.c b/gragl.c
new file mode 100644
index 0000000..430b581
--- /dev/null
+++ b/gragl.c
@@ -0,0 +1,198 @@
+#include <stdarg.h>
+#include <GL/freeglut.h>
+#include <memory.h>
+#include <stdio.h>
+#include <math.h>
+
+#include "gragl.h"
+
+#define SUBWINDOWS 64
+
+Plot2dGroup * target = NULL;
+
+int subwindows[SUBWINDOWS];
+
+static void enable_multi_sample() {
+	glEnable(GL_MULTISAMPLE);
+	glHint(GL_MULTISAMPLE_FILTER_HINT_NV, GL_NICEST);
+}
+
+static void draw_function(double from, double to, double step, Scalar(*fun)(double)) {
+	glColor3f(0.9f, 0.5f, 0.2f);
+	glLineWidth(2);
+	glBegin(GL_LINES);
+
+	for (double i = from; i < to; i += step) {
+		Scalar current = fun(i);
+		Scalar next = fun(i + step);
+
+		if (current.valid) {
+			glVertex2f(i, current.v);
+			glVertex2f(i + step, next.v);
+		}
+	}
+
+	glEnd();
+}
+
+void draw_axis() {
+	glColor3f(1, 1, 1);
+	glLineWidth(2);
+	glBegin(GL_LINES);
+
+	glVertex2f(0, 0);
+	glVertex2f(1, 0);
+	glVertex2f(0, 0);
+	glVertex2f(0, 1);
+
+	glVertex2f(1, 0);
+	glVertex2f(0.9, 0.1);
+	glVertex2f(1, 0);
+	glVertex2f(0.9, -0.1);
+
+	glVertex2f(0, 1);
+	glVertex2f(0.1, 0.9);
+	glVertex2f(0, 1);
+	glVertex2f(-0.1, 0.9);
+
+	glEnd();
+}
+
+void draw_grid(double from, double to) {
+	glColor3f(0.2, 0.2, 0.2);
+
+	double yl = (from + to) / 2 + 1;
+
+	glLineWidth(2);
+	glBegin(GL_LINES);
+
+	for (double i = from; i < to; ++i) {
+		glVertex2f(i, yl);
+		glVertex2f(i, -yl);
+	}
+
+	for (double i = -yl; i < yl; ++i) {
+		glVertex2f(from, i);
+		glVertex2f(to, i);
+	}
+
+	glEnd();
+
+	glColor3f(0.5, 0.5, 0.5);
+	glBegin(GL_LINES);
+	glVertex2f(from, 0);
+	glVertex2f(to, 0);
+
+	glVertex2f(0, yl);
+	glVertex2f(0, -yl);
+	glEnd();
+
+	glColor3f(0.7, 0.7, 0.7);
+	glBegin(GL_LINE_LOOP);
+	glVertex2f(from, yl);
+	glVertex2f(to, yl);
+	glVertex2f(to, -yl);
+	glVertex2f(from, -yl);
+	glEnd();
+}
+
+static void update() {
+	glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
+	int window = glutGetWindow();
+	int plot_id = 0;
+
+	while (subwindows[plot_id] != window) ++plot_id;
+
+	Plot2d * plot = &(target->plots[plot_id]);
+
+	double translate = -((plot->to + plot->from) / 2);
+	double zoom = 2 / (plot->to - plot->from);
+	glScalef(zoom, zoom, zoom);
+	glTranslatef(translate, 0, 0);
+
+	draw_grid(plot->from, plot->to);
+	draw_axis();
+	draw_function(plot->from, plot->to, plot->step, plot->func);
+
+	glTranslatef(-translate, 0, 0);
+	glScalef(1/zoom, 1/zoom, 1/zoom);
+
+	glutSwapBuffers();
+}
+
+static void parent_update() {
+	glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
+	glutSwapBuffers();
+
+	int width = glutGet(GLUT_WINDOW_WIDTH);
+	int height = glutGet(GLUT_WINDOW_HEIGHT);
+	int min = width > height ? height : width;
+
+	unsigned n_plots = ((unsigned)sqrt(target->n));
+
+	int plot_dim = min / (int)n_plots - (int)target->padding / 4;
+
+	plot_dim = plot < 0 ? 1 : plot_dim;
+
+	for (unsigned i = 0; i < SUBWINDOWS && subwindows[i] > 0; ++i) {
+		glutSetWindow(subwindows[i]);
+		glutReshapeWindow(
+				plot_dim - target->padding / 2,
+				plot_dim - target->padding / 2
+		);
+		glutPositionWindow(
+				(i % n_plots) * plot_dim + target->padding / 2,
+				(i / n_plots) * plot_dim + target->padding / 2
+		);
+	}
+}
+
+void plot(Plot2dGroup * group) {
+	target = group;
+
+	char * arg[1] = { "" };
+	int argc = 1;
+
+	glutInit(&argc, arg);
+	glutInitWindowSize(500, 500);
+	glutSetOption(GLUT_MULTISAMPLE, 8);
+	glutInitDisplayMode(GLUT_RGB | GLUT_DOUBLE | GLUT_DEPTH | GLUT_MULTISAMPLE);
+	int parent = glutCreateWindow("GRAGL");
+
+	for (int i = 0; i < group->n; ++i) {
+		int id = glutCreateSubWindow(parent, 1, 1, 1, 1);
+		subwindows[i] = id;
+		glutSetWindow(id);
+		glutDisplayFunc(update);
+	}
+
+	glutSetWindow(parent);
+	glutDisplayFunc(parent_update);
+
+	enable_multi_sample();
+
+	glutMainLoop();
+}
+
+Plot2dGroup * create_plot2d_group(int num_args, ...) {
+	Plot2dGroup * group = (Plot2dGroup*)malloc(sizeof(Plot2dGroup));
+	group->plots = (Plot2d*)malloc(sizeof(Plot2d) * num_args);
+
+	group->n = num_args;
+	group->padding = 20;
+
+	va_list ap;
+	va_start(ap, num_args);
+
+	for (int i = 0; i < num_args; ++i) {
+		group->plots[i] = va_arg(ap, Plot2d);
+	}
+	va_end(ap);
+
+	return group;
+}
+
+void free_plot2d_group(Plot2dGroup * group) {
+	free(group->plots);
+	free(group);
+}