/*
* 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-3.0-compliant.
+ * OpenGL-3.1-compliant.
* A smooth shaded polygon is drawn in a 2-D projection.
*/
#include <GL/freeglut.h>
#include <stdlib.h>
#include <stdio.h>
+#include <stddef.h>
#include <string.h>
/* report GL errors, if any, to stderr */
typedef ptrdiff_t ourGLsizeiptr;
typedef char ourGLchar;
-typedef void (*PFNGLGENBUFFERSPROC) (GLsizei n, GLuint *buffers);
-PFNGLGENBUFFERSPROC gl_GenBuffers;
+#ifndef APIENTRY
+#define APIENTRY
+#endif
-typedef void (*PFNGLBINDBUFFERPROC) (GLenum target, GLuint buffer);
-PFNGLBINDBUFFERPROC gl_BindBuffer;
-typedef void (*PFNGLBUFFERDATAPROC) (GLenum target, ourGLsizeiptr size,
- const GLvoid *data, GLenum usage);
-PFNGLBUFFERDATAPROC gl_BufferData;
+#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
-typedef GLuint (*PFNGLCREATESHADERPROC) (GLenum type);
+PFNGLGENVERTEXARRAYSPROC gl_GenVertexArrays;
+PFNGLBINDVERTEXARRAYPROC gl_BindVertexArray;
+PFNGLGENBUFFERSPROC gl_GenBuffers;
+PFNGLBINDBUFFERPROC gl_BindBuffer;
+PFNGLBUFFERDATAPROC gl_BufferData;
PFNGLCREATESHADERPROC gl_CreateShader;
-
-typedef void (*PFNGLSHADERSOURCEPROC)
- (GLuint shader, GLsizei count, const ourGLchar **string, const GLint *length);
PFNGLSHADERSOURCEPROC gl_ShaderSource;
-
-typedef void (*PFNGLCOMPILESHADERPROC) (GLuint shader);
PFNGLCOMPILESHADERPROC gl_CompileShader;
-
-typedef GLuint (*PFNGLCREATEPROGRAMPROC) (void);
PFNGLCREATEPROGRAMPROC gl_CreateProgram;
-
-typedef void (*PFNGLATTACHSHADERPROC) (GLuint program, GLuint shader);
PFNGLATTACHSHADERPROC gl_AttachShader;
-
-typedef void (*PFNGLLINKPROGRAMPROC) (GLuint program);
PFNGLLINKPROGRAMPROC gl_LinkProgram;
-
-typedef void (*PFNGLUSEPROGRAMPROC) (GLuint program);
PFNGLUSEPROGRAMPROC gl_UseProgram;
-
-typedef void (*PFNGLGETSHADERIVPROC) (GLuint shader, GLenum pname, GLint *params);
PFNGLGETSHADERIVPROC gl_GetShaderiv;
-
-typedef void (*PFNGLGETSHADERINFOLOGPROC)
- (GLuint shader, GLsizei bufSize, GLsizei *length, ourGLchar *infoLog);
PFNGLGETSHADERINFOLOGPROC gl_GetShaderInfoLog;
-
-typedef void (*PFNGLGETPROGRAMIVPROC) (GLenum target, GLenum pname, GLint *params);
PFNGLGETPROGRAMIVPROC gl_GetProgramiv;
-
-typedef void (*PFNGLGETPROGRAMINFOLOGPROC)
- (GLuint program, GLsizei bufSize, GLsizei *length, ourGLchar *infoLog);
PFNGLGETPROGRAMINFOLOGPROC gl_GetProgramInfoLog;
-
-typedef GLint (*PFNGLGETATTRIBLOCATIONPROC) (GLuint program, const ourGLchar *name);
PFNGLGETATTRIBLOCATIONPROC gl_GetAttribLocation;
-
-typedef void (*PFNGLVERTEXATTRIBPOINTERPROC)
- (GLuint index, GLint size, GLenum type, GLboolean normalized, GLsizei stride,
- const GLvoid *pointer);
PFNGLVERTEXATTRIBPOINTERPROC gl_VertexAttribPointer;
-
-typedef void (*PFNGLENABLEVERTEXATTRIBARRAYPROC) (GLuint index);
PFNGLENABLEVERTEXATTRIBARRAYPROC gl_EnableVertexAttribArray;
-
-typedef GLint (*PFNGLGETUNIFORMLOCATIONPROC) (GLuint program, const ourGLchar *name);
PFNGLGETUNIFORMLOCATIONPROC gl_GetUniformLocation;
-
-typedef void (*PFNGLUNIFORMMATRIX4FVPROC)
- (GLint location, GLsizei count, GLboolean transpose, const GLfloat *value);
PFNGLUNIFORMMATRIX4FVPROC gl_UniformMatrix4fv;
-void initExtensionEntries(void)
+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_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
/* 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);
}
const ourGLchar *vertexShaderSource[] = {
- "#version 130\n",
+ "#version 140\n",
"uniform mat4 fg_ProjectionMatrix;\n",
"in vec4 fg_Color;\n",
"in vec4 fg_Vertex;\n",
- "void main(void)\n",
+ "smooth out vec4 fg_SmoothColor;\n",
+ "void main()\n",
"{\n",
- " gl_FrontColor = fg_Color;\n",
+ " fg_SmoothColor = fg_Color;\n",
" gl_Position = fg_ProjectionMatrix * fg_Vertex;\n",
"}\n"
};
const ourGLchar *fragmentShaderSource[] = {
- "#version 130\n",
+ "#version 140\n",
+ "smooth in vec4 fg_SmoothColor;\n",
"out vec4 fg_FragColor;\n",
"void main(void)\n",
"{\n",
- " fg_FragColor = gl_Color;\n",
+ " fg_FragColor = fg_SmoothColor;\n",
"}\n"
};
void initRendering(void)
{
glClearColor (0.0, 0.0, 0.0, 0.0);
- glShadeModel (GL_SMOOTH);
checkError ("initRendering");
}
{
glViewport (0, 0, (GLsizei) w, (GLsizei) h);
if (w <= h) {
- loadOrtho2Df (projectionMatrix, 0.0, 30.0, 0.0, 30.0 * (GLfloat) h/(GLfloat) w);
+ loadOrtho2Df (projectionMatrix, 0.0f, 30.0f, 0.0f, 30.0f * (GLfloat) h/(GLfloat) w);
} else {
- loadOrtho2Df (projectionMatrix, 0.0, 30.0 * (GLfloat) w/(GLfloat) h, 0.0, 30.0);
+ loadOrtho2Df (projectionMatrix, 0.0f, 30.0f * (GLfloat) w/(GLfloat) h, 0.0f, 30.0f);
}
checkError ("reshape");
}
{
glutInit(&argc, argv);
glutInitDisplayMode (GLUT_SINGLE | GLUT_RGB);
- /* add command line argument "classic" for a pre-3.0 context */
+ /* add command line argument "classic" for a pre-3.x context */
if ((argc != 2) || (strcmp (argv[1], "classic") != 0)) {
- glutInitContextVersion (3, 0);
+ glutInitContextVersion (3, 1);
glutInitContextFlags (GLUT_FORWARD_COMPATIBLE | GLUT_DEBUG);
}
glutInitWindowSize (500, 500);