This repository has been archived on 2024-06-25. You can view files and clone it, but cannot push or open issues or pull requests.
FreeGLUT-Vita/progs/demos/smooth_opengl3/smooth_opengl3.c
2020-10-29 22:28:16 +03:00

470 lines
16 KiB
C

/*
* 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;
}