From 659b82e6c2b06f6f14a96da383ff45a56b937d93 Mon Sep 17 00:00:00 2001
From: Wolfgang Draxinger <Wolfgang.Draxinger@draxit.de>
Date: Wed, 2 Nov 2011 22:46:06 +0100
Subject: Simplemost example for managing input with GLUT altering the state of
 the rendered scene.

---
 .../glut_input_transforms/glut_input_transforms.c  | 81 ++++++++++++++++++++++
 1 file changed, 81 insertions(+)
 create mode 100644 samples/OpenGL/glut_input_transforms/glut_input_transforms.c

diff --git a/samples/OpenGL/glut_input_transforms/glut_input_transforms.c b/samples/OpenGL/glut_input_transforms/glut_input_transforms.c
new file mode 100644
index 0000000..b23f5f0
--- /dev/null
+++ b/samples/OpenGL/glut_input_transforms/glut_input_transforms.c
@@ -0,0 +1,81 @@
+#include <math.h>
+#include <GL/gl.h>
+#include <GL/glut.h>
+
+struct {
+	float triangle_rotation;
+} scene;
+
+static const GLfloat triangle_vertices[3][3] = {
+	{-1., -1., 0.},
+	{ 1., -1., 0.},
+	{ 0., 0.732, 0.}
+};
+
+static void draw_triangle()
+{
+	glEnableClientState(GL_VERTEX_ARRAY);
+	glVertexPointer(3, GL_FLOAT, 3*sizeof(GLfloat), &triangle_vertices[0][0]);
+	glDrawArrays(GL_TRIANGLES, 0, 3);
+	glDisableClientState(GL_VERTEX_ARRAY);
+}
+
+static void display(void)
+{
+	const int window_width = glutGet(GLUT_WINDOW_WIDTH);
+	const int window_height = glutGet(GLUT_WINDOW_HEIGHT);
+	if( !window_width || !window_height )
+		return;
+	const float window_aspect = (float)window_width / (float)window_height;
+
+	glDisable(GL_SCISSOR_TEST);
+
+	glClearColor(0.4, 0.3, 0.5, 1.0);
+	glClearDepth(1.0);
+	glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
+
+	glViewport(0, 0, window_width, window_height);
+
+	glMatrixMode(GL_PROJECTION);
+	glLoadIdentity();
+	glFrustum(-window_aspect, window_aspect, -1, 1, 2, 10);
+
+	glMatrixMode(GL_MODELVIEW);
+	glLoadIdentity();
+	glTranslatef(0., 0., -5.);
+
+	glPushMatrix();
+	glRotatef(scene.triangle_rotation, 0., 1., 0.);
+	draw_triangle();
+	glPopMatrix();
+
+	glutSwapBuffers();
+}
+
+static void special_key(int key, int x, int y)
+{
+	switch(key) {
+	case GLUT_KEY_LEFT:
+		scene.triangle_rotation = fmod(scene.triangle_rotation + 5, 360);
+		break;
+	case GLUT_KEY_RIGHT:
+		scene.triangle_rotation = fmod(scene.triangle_rotation - 5, 360);
+		break;
+	default:
+		break;
+	}
+	glutPostRedisplay();
+}
+
+int main(int argc, char *argv[])
+{
+	glutInit(&argc, argv);
+
+	glutInitDisplayMode(GLUT_RGB | GLUT_DOUBLE);
+	glutCreateWindow("Simple input altering scene demo");
+	glutDisplayFunc(display);
+	glutSpecialFunc(special_key);
+
+	glutMainLoop();
+}
+
-- 
cgit v1.2.3