--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/mupdf-source/thirdparty/freeglut/progs/demos/smooth_opengl3/smooth_opengl3.c	Mon Sep 15 11:43:07 2025 +0200
@@ -0,0 +1,469 @@
+/*
+ * smooth_opengl3.c, based on smooth.c, which is (c) by SGI, see below.
+ * This program demonstrates smooth shading in a way which is fully
+ * OpenGL-3.1-compliant.
+ * A smooth shaded polygon is drawn in a 2-D projection.
+ */
+
+/*
+ * Original copyright notice from smooth.c:
+ *
+ * License Applicability. Except to the extent portions of this file are
+ * made subject to an alternative license as permitted in the SGI Free
+ * Software License B, Version 1.1 (the "License"), the contents of this
+ * file are subject only to the provisions of the License. You may not use
+ * this file except in compliance with the License. You may obtain a copy
+ * of the License at Silicon Graphics, Inc., attn: Legal Services, 1600
+ * Amphitheatre Parkway, Mountain View, CA 94043-1351, or at:
+ * 
+ * http://oss.sgi.com/projects/FreeB
+ * 
+ * Note that, as provided in the License, the Software is distributed on an
+ * "AS IS" basis, with ALL EXPRESS AND IMPLIED WARRANTIES AND CONDITIONS
+ * DISCLAIMED, INCLUDING, WITHOUT LIMITATION, ANY IMPLIED WARRANTIES AND
+ * CONDITIONS OF MERCHANTABILITY, SATISFACTORY QUALITY, FITNESS FOR A
+ * PARTICULAR PURPOSE, AND NON-INFRINGEMENT.
+ * 
+ * Original Code. The Original Code is: OpenGL Sample Implementation,
+ * Version 1.2.1, released January 26, 2000, developed by Silicon Graphics,
+ * Inc. The Original Code is Copyright (c) 1991-2000 Silicon Graphics, Inc.
+ * Copyright in any portions created by third parties is as indicated
+ * elsewhere herein. All Rights Reserved.
+ * 
+ * Additional Notice Provisions: The application programming interfaces
+ * established by SGI in conjunction with the Original Code are The
+ * OpenGL(R) Graphics System: A Specification (Version 1.2.1), released
+ * April 1, 1999; The OpenGL(R) Graphics System Utility Library (Version
+ * 1.3), released November 4, 1998; and OpenGL(R) Graphics with the X
+ * Window System(R) (Version 1.3), released October 19, 1998. This software
+ * was created using the OpenGL(R) version 1.2.1 Sample Implementation
+ * published by SGI, but has not been independently verified as being
+ * compliant with the OpenGL(R) version 1.2.1 Specification.
+ *
+ */
+
+#include <GL/freeglut.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <stddef.h>
+#include <string.h>
+
+/* report GL errors, if any, to stderr */
+void checkError(const char *functionName)
+{
+   GLenum error;
+   while (( error = glGetError() ) != GL_NO_ERROR) {
+      fprintf (stderr, "GL error 0x%X detected in %s\n", error, functionName);
+   }
+}
+
+/* extension #defines, types and entries, avoiding a dependency on additional
+   libraries like GLEW or the GL/glext.h header */
+#ifndef GL_ARRAY_BUFFER
+#define GL_ARRAY_BUFFER 0x8892
+#endif
+
+#ifndef GL_STATIC_DRAW
+#define GL_STATIC_DRAW 0x88E4
+#endif
+
+#ifndef GL_FRAGMENT_SHADER
+#define GL_FRAGMENT_SHADER 0x8B30
+#endif
+
+#ifndef GL_VERTEX_SHADER
+#define GL_VERTEX_SHADER 0x8B31
+#endif
+
+#ifndef GL_SHADING_LANGUAGE_VERSION
+#define GL_SHADING_LANGUAGE_VERSION 0x8B8C
+#endif
+
+#ifndef GL_COMPILE_STATUS
+#define GL_COMPILE_STATUS 0x8B81
+#endif
+
+#ifndef GL_LINK_STATUS
+#define GL_LINK_STATUS 0x8B82
+#endif
+
+#ifndef GL_INFO_LOG_LENGTH
+#define GL_INFO_LOG_LENGTH 0x8B84
+#endif
+
+typedef ptrdiff_t ourGLsizeiptr;
+typedef char ourGLchar;
+
+#ifndef APIENTRY
+#define APIENTRY
+#endif
+
+
+#ifndef GL_ARB_vertex_array_object
+typedef void (APIENTRY *PFNGLGENVERTEXARRAYSPROC) (GLsizei n, GLuint *arrays);
+typedef void (APIENTRY *PFNGLBINDVERTEXARRAYPROC) (GLuint array);
+#endif
+#ifndef GL_VERSION_1_5
+typedef void (APIENTRY *PFNGLGENBUFFERSPROC) (GLsizei n, GLuint *buffers);
+typedef void (APIENTRY *PFNGLBINDBUFFERPROC) (GLenum target, GLuint buffer);
+typedef void (APIENTRY *PFNGLBUFFERDATAPROC) (GLenum target, ourGLsizeiptr size, const GLvoid *data, GLenum usage);
+#endif
+#ifndef GL_VERSION_2_0
+typedef GLuint (APIENTRY *PFNGLCREATESHADERPROC) (GLenum type);
+typedef void (APIENTRY *PFNGLSHADERSOURCEPROC) (GLuint shader, GLsizei count, const ourGLchar **string, const GLint *length);
+typedef void (APIENTRY *PFNGLCOMPILESHADERPROC) (GLuint shader);
+typedef GLuint (APIENTRY *PFNGLCREATEPROGRAMPROC) (void);
+typedef void (APIENTRY *PFNGLATTACHSHADERPROC) (GLuint program, GLuint shader);
+typedef void (APIENTRY *PFNGLLINKPROGRAMPROC) (GLuint program);
+typedef void (APIENTRY *PFNGLUSEPROGRAMPROC) (GLuint program);
+typedef void (APIENTRY *PFNGLGETSHADERIVPROC) (GLuint shader, GLenum pname, GLint *params);
+typedef void (APIENTRY *PFNGLGETSHADERINFOLOGPROC) (GLuint shader, GLsizei bufSize, GLsizei *length, ourGLchar *infoLog);
+typedef void (APIENTRY *PFNGLGETPROGRAMIVPROC) (GLenum target, GLenum pname, GLint *params);
+typedef void (APIENTRY *PFNGLGETPROGRAMINFOLOGPROC) (GLuint program, GLsizei bufSize, GLsizei *length, ourGLchar *infoLog);
+typedef GLint (APIENTRY *PFNGLGETATTRIBLOCATIONPROC) (GLuint program, const ourGLchar *name);
+typedef void (APIENTRY *PFNGLVERTEXATTRIBPOINTERPROC) (GLuint index, GLint size, GLenum type, GLboolean normalized, GLsizei stride, const GLvoid *pointer);
+typedef void (APIENTRY *PFNGLENABLEVERTEXATTRIBARRAYPROC) (GLuint index);
+typedef GLint (APIENTRY *PFNGLGETUNIFORMLOCATIONPROC) (GLuint program, const ourGLchar *name);
+typedef void (APIENTRY *PFNGLUNIFORMMATRIX4FVPROC) (GLint location, GLsizei count, GLboolean transpose, const GLfloat *value);
+#endif
+
+PFNGLGENVERTEXARRAYSPROC gl_GenVertexArrays;
+PFNGLBINDVERTEXARRAYPROC gl_BindVertexArray;
+PFNGLGENBUFFERSPROC gl_GenBuffers;
+PFNGLBINDBUFFERPROC gl_BindBuffer;
+PFNGLBUFFERDATAPROC gl_BufferData;
+PFNGLCREATESHADERPROC gl_CreateShader;
+PFNGLSHADERSOURCEPROC gl_ShaderSource;
+PFNGLCOMPILESHADERPROC gl_CompileShader;
+PFNGLCREATEPROGRAMPROC gl_CreateProgram;
+PFNGLATTACHSHADERPROC gl_AttachShader;
+PFNGLLINKPROGRAMPROC gl_LinkProgram;
+PFNGLUSEPROGRAMPROC gl_UseProgram;
+PFNGLGETSHADERIVPROC gl_GetShaderiv;
+PFNGLGETSHADERINFOLOGPROC gl_GetShaderInfoLog;
+PFNGLGETPROGRAMIVPROC gl_GetProgramiv;
+PFNGLGETPROGRAMINFOLOGPROC gl_GetProgramInfoLog;
+PFNGLGETATTRIBLOCATIONPROC gl_GetAttribLocation;
+PFNGLVERTEXATTRIBPOINTERPROC gl_VertexAttribPointer;
+PFNGLENABLEVERTEXATTRIBARRAYPROC gl_EnableVertexAttribArray;
+PFNGLGETUNIFORMLOCATIONPROC gl_GetUniformLocation;
+PFNGLUNIFORMMATRIX4FVPROC gl_UniformMatrix4fv;
+
+void initExtensionEntries(void)
+{
+   gl_GenVertexArrays = (PFNGLGENVERTEXARRAYSPROC) glutGetProcAddress ("glGenVertexArrays");
+   gl_BindVertexArray = (PFNGLBINDVERTEXARRAYPROC) glutGetProcAddress ("glBindVertexArray");
+   if (!gl_GenVertexArrays || !gl_BindVertexArray)
+   {
+       fprintf (stderr, "glGenVertexArrays or glBindVertexArray not found");
+       exit(1);
+   }
+   gl_GenBuffers = (PFNGLGENBUFFERSPROC) glutGetProcAddress ("glGenBuffers");
+   gl_BindBuffer = (PFNGLBINDBUFFERPROC) glutGetProcAddress ("glBindBuffer");
+   gl_BufferData = (PFNGLBUFFERDATAPROC) glutGetProcAddress ("glBufferData");
+   if (!gl_GenBuffers || !gl_BindBuffer || !gl_BufferData)
+   {
+       fprintf (stderr, "glGenBuffers, glBindBuffer or glBufferData not found");
+       exit(1);
+   }
+   gl_CreateShader = (PFNGLCREATESHADERPROC) glutGetProcAddress ("glCreateShader");
+   gl_ShaderSource = (PFNGLSHADERSOURCEPROC) glutGetProcAddress ("glShaderSource");
+   gl_CompileShader = (PFNGLCOMPILESHADERPROC) glutGetProcAddress ("glCompileShader");
+   gl_CreateProgram = (PFNGLCREATEPROGRAMPROC) glutGetProcAddress ("glCreateProgram");
+   gl_AttachShader = (PFNGLATTACHSHADERPROC) glutGetProcAddress ("glAttachShader");
+   gl_LinkProgram = (PFNGLLINKPROGRAMPROC) glutGetProcAddress ("glLinkProgram");
+   gl_UseProgram = (PFNGLUSEPROGRAMPROC) glutGetProcAddress ("glUseProgram");
+   gl_GetShaderiv = (PFNGLGETSHADERIVPROC) glutGetProcAddress ("glGetShaderiv");
+   gl_GetShaderInfoLog = (PFNGLGETSHADERINFOLOGPROC) glutGetProcAddress ("glGetShaderInfoLog");
+   gl_GetProgramiv = (PFNGLGETPROGRAMIVPROC) glutGetProcAddress ("glGetProgramiv");
+   gl_GetProgramInfoLog = (PFNGLGETPROGRAMINFOLOGPROC) glutGetProcAddress ("glGetProgramInfoLog");
+   gl_GetAttribLocation = (PFNGLGETATTRIBLOCATIONPROC) glutGetProcAddress ("glGetAttribLocation");
+   gl_VertexAttribPointer = (PFNGLVERTEXATTRIBPOINTERPROC) glutGetProcAddress ("glVertexAttribPointer");
+   gl_EnableVertexAttribArray = (PFNGLENABLEVERTEXATTRIBARRAYPROC) glutGetProcAddress ("glEnableVertexAttribArray");
+   gl_GetUniformLocation = (PFNGLGETUNIFORMLOCATIONPROC) glutGetProcAddress ("glGetUniformLocation");
+   gl_UniformMatrix4fv = (PFNGLUNIFORMMATRIX4FVPROC) glutGetProcAddress ("glUniformMatrix4fv");
+   if (!gl_CreateShader || !gl_ShaderSource || !gl_CompileShader || !gl_CreateProgram || !gl_AttachShader || !gl_LinkProgram || !gl_UseProgram || !gl_GetShaderiv || !gl_GetShaderInfoLog || !gl_GetProgramiv || !gl_GetProgramInfoLog || !gl_GetAttribLocation || !gl_VertexAttribPointer || !gl_EnableVertexAttribArray || !gl_GetUniformLocation || !gl_UniformMatrix4fv)
+   {
+       fprintf (stderr, "glCreateShader, glShaderSource, glCompileShader, glCreateProgram, glAttachShader, glLinkProgram, glUseProgram, glGetShaderiv, glGetShaderInfoLog, glGetProgramiv, glGetProgramInfoLog, glGetAttribLocation, glVertexAttribPointer, glEnableVertexAttribArray, glGetUniformLocation or glUniformMatrix4fv not found");
+       exit(1);
+   }
+}
+
+/* vertex array data for a colored 2D triangle, consisting of RGB color values
+   and XY coordinates */
+const GLfloat varray[] = {
+   1.0f, 0.0f, 0.0f, /* red */
+   5.0f, 5.0f,       /* lower left */
+
+   0.0f, 1.0f, 0.0f, /* green */
+   25.0f, 5.0f,      /* lower right */
+
+   0.0f, 0.0f, 1.0f, /* blue */
+   5.0f, 25.0f       /* upper left */
+};
+
+/* ISO C somehow enforces this silly use of 'enum' for compile-time constants */
+enum {
+  numColorComponents = 3,
+  numVertexComponents = 2,
+  stride = sizeof(GLfloat) * (numColorComponents + numVertexComponents),
+  numElements = sizeof(varray) / stride
+};
+
+/* the name of the vertex buffer object */
+GLuint vertexBufferName;
+GLuint vertexArrayName;
+
+void initBuffer(void)
+{
+   /* Need to setup a vertex array as otherwise invalid operation errors can
+    * occur when accessing vertex buffer (OpenGL 3.3 has no default zero named
+    * vertex array) 
+    */
+   gl_GenVertexArrays(1, &vertexArrayName);
+   gl_BindVertexArray(vertexArrayName);
+
+   gl_GenBuffers (1, &vertexBufferName);
+   gl_BindBuffer (GL_ARRAY_BUFFER, vertexBufferName);
+   gl_BufferData (GL_ARRAY_BUFFER, sizeof(varray), varray, GL_STATIC_DRAW);
+   checkError ("initBuffer");
+}
+
+const ourGLchar *vertexShaderSource[] = {
+   "#version 140\n",
+   "uniform mat4 fg_ProjectionMatrix;\n",
+   "in vec4 fg_Color;\n",
+   "in vec4 fg_Vertex;\n",
+   "smooth out vec4 fg_SmoothColor;\n",
+   "void main()\n",
+   "{\n",
+   "   fg_SmoothColor = fg_Color;\n",
+   "   gl_Position = fg_ProjectionMatrix * fg_Vertex;\n",
+   "}\n"
+};
+
+const ourGLchar *fragmentShaderSource[] = {
+   "#version 140\n",
+   "smooth in vec4 fg_SmoothColor;\n",
+   "out vec4 fg_FragColor;\n",
+   "void main(void)\n",
+   "{\n",
+   "   fg_FragColor = fg_SmoothColor;\n",
+   "}\n"
+};
+
+void compileAndCheck(GLuint shader)
+{
+   GLint status;
+   gl_CompileShader (shader);
+   gl_GetShaderiv (shader, GL_COMPILE_STATUS, &status);
+   if (status == GL_FALSE) {
+     GLint infoLogLength;
+     ourGLchar *infoLog;
+     gl_GetShaderiv (shader, GL_INFO_LOG_LENGTH, &infoLogLength);
+     infoLog = (ourGLchar*) malloc (infoLogLength);
+     gl_GetShaderInfoLog (shader, infoLogLength, NULL, infoLog);
+     fprintf (stderr, "compile log: %s\n", infoLog);
+     free (infoLog);
+   }
+}
+
+GLuint compileShaderSource(GLenum type, GLsizei count, const ourGLchar **string)
+{
+   GLuint shader = gl_CreateShader (type);
+   gl_ShaderSource (shader, count, string, NULL);
+   compileAndCheck (shader);
+   return shader;
+}
+
+void linkAndCheck(GLuint program)
+{
+   GLint status;
+   gl_LinkProgram (program);
+   gl_GetProgramiv (program, GL_LINK_STATUS, &status);
+   if (status == GL_FALSE) {
+     GLint infoLogLength;
+     ourGLchar *infoLog;
+     gl_GetProgramiv (program, GL_INFO_LOG_LENGTH, &infoLogLength);
+     infoLog = (ourGLchar*) malloc (infoLogLength);
+     gl_GetProgramInfoLog (program, infoLogLength, NULL, infoLog);
+     fprintf (stderr, "link log: %s\n", infoLog);
+     free (infoLog);
+   }
+}
+
+GLuint createProgram(GLuint vertexShader, GLuint fragmentShader)
+{
+   GLuint program = gl_CreateProgram ();
+   if (vertexShader != 0) {
+      gl_AttachShader (program, vertexShader);
+   }
+   if (fragmentShader != 0) {
+      gl_AttachShader (program, fragmentShader);
+   }
+   linkAndCheck (program);
+   return program;
+}
+
+GLuint fgProjectionMatrixIndex;
+GLuint fgColorIndex;
+GLuint fgVertexIndex;
+
+void initShader(void)
+{
+   const GLsizei vertexShaderLines = sizeof(vertexShaderSource) / sizeof(ourGLchar*);
+   GLuint vertexShader =
+     compileShaderSource (GL_VERTEX_SHADER, vertexShaderLines, vertexShaderSource);
+
+   const GLsizei fragmentShaderLines = sizeof(fragmentShaderSource) / sizeof(ourGLchar*);
+   GLuint fragmentShader =
+     compileShaderSource (GL_FRAGMENT_SHADER, fragmentShaderLines, fragmentShaderSource);
+
+   GLuint program = createProgram (vertexShader, fragmentShader);
+
+   gl_UseProgram (program);
+
+   fgProjectionMatrixIndex = gl_GetUniformLocation(program, "fg_ProjectionMatrix");
+
+   fgColorIndex = gl_GetAttribLocation(program, "fg_Color");
+   gl_EnableVertexAttribArray (fgColorIndex);
+
+   fgVertexIndex = gl_GetAttribLocation(program, "fg_Vertex");
+   gl_EnableVertexAttribArray (fgVertexIndex);
+
+   checkError ("initShader");
+}
+
+void initRendering(void)
+{
+   glClearColor (0.0, 0.0, 0.0, 0.0);
+   checkError ("initRendering");
+}
+
+void init(void) 
+{
+   initExtensionEntries ();
+   initBuffer ();
+   initShader ();
+   initRendering ();
+}
+
+void dumpInfo(void)
+{
+   printf ("Vendor: %s\n", glGetString (GL_VENDOR));
+   printf ("Renderer: %s\n", glGetString (GL_RENDERER));
+   printf ("Version: %s\n", glGetString (GL_VERSION));
+   printf ("GLSL: %s\n", glGetString (GL_SHADING_LANGUAGE_VERSION));
+   checkError ("dumpInfo");
+}
+
+const GLvoid *bufferObjectPtr (GLsizei index)
+{
+   return (const GLvoid *) (((char *) NULL) + index);
+}
+
+GLfloat projectionMatrix[16];
+
+void triangle(void)
+{
+   gl_UniformMatrix4fv (fgProjectionMatrixIndex, 1, GL_FALSE, projectionMatrix);
+
+   gl_BindBuffer (GL_ARRAY_BUFFER, vertexBufferName);
+   gl_VertexAttribPointer (fgColorIndex, numColorComponents, GL_FLOAT, GL_FALSE,
+                           stride, bufferObjectPtr (0));
+   gl_VertexAttribPointer (fgVertexIndex, numVertexComponents, GL_FLOAT, GL_FALSE,
+                           stride, bufferObjectPtr (sizeof(GLfloat) * numColorComponents));
+   glDrawArrays(GL_TRIANGLES, 0, numElements);
+   checkError ("triangle");
+}
+
+void display(void)
+{
+   glClear (GL_COLOR_BUFFER_BIT);
+   triangle ();
+   glFlush ();
+   checkError ("display");
+}
+
+void loadOrthof(GLfloat *m, GLfloat l, GLfloat r, GLfloat b, GLfloat t,
+                GLfloat n, GLfloat f)
+{
+   m[ 0] = 2.0f / (r - l);
+   m[ 1] = 0.0f;
+   m[ 2] = 0.0f;
+   m[ 3] = 0.0f;
+
+   m[ 4] = 0.0f;
+   m[ 5] = 2.0f / (t - b);
+   m[ 6] = 0.0f;
+   m[ 7] = 0.0f;
+
+   m[ 8] = 0.0f;
+   m[ 9] = 0.0f;
+   m[10] = -2.0f / (f - n);
+   m[11] = 0.0f;
+
+   m[12] = -(r + l) / (r - l);
+   m[13] = -(t + b) / (t - b);
+   m[14] = -(f + n) / (f - n);
+   m[15] = 1.0f;
+}
+
+void loadOrtho2Df(GLfloat *m, GLfloat l, GLfloat r, GLfloat b, GLfloat t)
+{
+   loadOrthof (m, l, r, b, t, -1.0f, 1.0f);
+}
+
+void reshape (int w, int h)
+{
+   glViewport (0, 0, (GLsizei) w, (GLsizei) h);
+   if (w <= h) {
+      loadOrtho2Df (projectionMatrix, 0.0f, 30.0f, 0.0f, 30.0f * (GLfloat) h/(GLfloat) w);
+   } else {
+      loadOrtho2Df (projectionMatrix, 0.0f, 30.0f * (GLfloat) w/(GLfloat) h, 0.0f, 30.0f);
+   }
+   checkError ("reshape");
+}
+
+void keyboard(unsigned char key, int x, int y)
+{
+   switch (key) {
+      case 27:
+         exit(0);
+         break;
+   }
+}
+
+void samplemenu(int menuID)
+{}
+
+int main(int argc, char** argv)
+{
+   int menuA;
+   glutInit(&argc, argv);
+   glutInitDisplayMode (GLUT_SINGLE | GLUT_RGB);
+   /* add command line argument "classic" for a pre-3.x context */
+   if ((argc != 2) || (strcmp (argv[1], "classic") != 0)) {
+      glutInitContextVersion (3, 1);
+      glutInitContextFlags (GLUT_FORWARD_COMPATIBLE | GLUT_DEBUG);
+   }
+   glutInitWindowSize (500, 500); 
+   glutInitWindowPosition (100, 100);
+   glutCreateWindow (argv[0]);
+   dumpInfo ();
+   init ();
+   glutDisplayFunc(display); 
+   glutReshapeFunc(reshape);
+   glutKeyboardFunc (keyboard);
+
+   /* Add a menu. They have their own context and should thus work with forward compatible main windows too. */
+   menuA = glutCreateMenu(samplemenu);
+   glutAddMenuEntry("Sub menu A1 (01)",1);
+   glutAddMenuEntry("Sub menu A2 (02)",2);
+   glutAddMenuEntry("Sub menu A3 (03)",3);
+   glutSetMenu(menuA);
+   glutAttachMenu(GLUT_RIGHT_BUTTON);
+
+   glutMainLoop();
+   return 0;
+}