Final changes to make the example fully OpenGL-3.0-compliant:

* Use vertex attribute arrays.

 * Use our own projection matrix.

 * Do not use deprecated vertex/fragment shader variables.


git-svn-id: https://svn.code.sf.net/p/freeglut/code/trunk@778 7f0cb862-5218-0410-a997-914c9d46530a
This commit is contained in:
spanne 2009-02-15 21:12:25 +00:00
parent 3d7236a470
commit cf85aaefef

View File

@ -58,6 +58,14 @@ void checkError(const char *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_VERTEX_SHADER
#define GL_VERTEX_SHADER 0x8B31
#endif
@ -92,7 +100,7 @@ typedef GLuint (*PFNGLCREATESHADERPROC) (GLenum type);
PFNGLCREATESHADERPROC gl_CreateShader;
typedef void (*PFNGLSHADERSOURCEPROC)
(GLuint shader, GLsizei count, const GLchar **string, const GLint *length);
(GLuint shader, GLsizei count, const GLchar **string, const GLint *length);
PFNGLSHADERSOURCEPROC gl_ShaderSource;
typedef void (*PFNGLCOMPILESHADERPROC) (GLuint shader);
@ -114,16 +122,34 @@ typedef void (*PFNGLGETSHADERIVPROC) (GLuint shader, GLenum pname, GLint *params
PFNGLGETSHADERIVPROC gl_GetShaderiv;
typedef void (*PFNGLGETSHADERINFOLOGPROC)
(GLuint shader, GLsizei bufSize, GLsizei *length, GLchar *infoLog);
(GLuint shader, GLsizei bufSize, GLsizei *length, GLchar *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, GLchar *infoLog);
(GLuint program, GLsizei bufSize, GLsizei *length, GLchar *infoLog);
PFNGLGETPROGRAMINFOLOGPROC gl_GetProgramInfoLog;
typedef GLint (*PFNGLGETATTRIBLOCATIONPROC) (GLuint program, const GLchar *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 GLchar *name);
PFNGLGETUNIFORMLOCATIONPROC gl_GetUniformLocation;
typedef void (*PFNGLUNIFORMMATRIX4FVPROC)
(GLint location, GLsizei count, GLboolean transpose, const GLfloat *value);
PFNGLUNIFORMMATRIX4FVPROC gl_UniformMatrix4fv;
void initExtensionEntries(void)
{
gl_GenBuffers = (PFNGLGENBUFFERSPROC) glutGetProcAddress ("glGenBuffers");
@ -140,6 +166,11 @@ void initExtensionEntries(void)
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");
}
/* vertex array data for a colored 2D triangle, consisting of RGB color values
@ -171,25 +202,27 @@ void initBuffer(void)
gl_GenBuffers (1, &vertexBufferName);
gl_BindBuffer (GL_ARRAY_BUFFER, vertexBufferName);
gl_BufferData (GL_ARRAY_BUFFER, sizeof(varray), varray, GL_STATIC_DRAW);
glEnableClientState (GL_COLOR_ARRAY);
glEnableClientState (GL_VERTEX_ARRAY);
checkError ("initBuffer");
}
const GLchar *vertexShaderSource[] = {
"#version 120\n",
"#version 130\n",
"uniform mat4 fg_ProjectionMatrix;\n",
"in vec4 fg_Color;\n",
"in vec4 fg_Vertex;\n",
"void main(void)\n",
"{\n",
" gl_FrontColor = gl_Color;\n",
" gl_Position = ftransform();\n",
" gl_FrontColor = fg_Color;\n",
" gl_Position = fg_ProjectionMatrix * fg_Vertex;\n",
"}\n"
};
const GLchar *fragmentShaderSource[] = {
"#version 120\n",
"#version 130\n",
"out vec4 fg_FragColor;\n",
"void main(void)\n",
"{\n",
" gl_FragColor = gl_Color;\n",
" fg_FragColor = gl_Color;\n",
"}\n"
};
@ -237,15 +270,19 @@ GLuint createProgram(GLuint vertexShader, GLuint fragmentShader)
{
GLuint program = gl_CreateProgram ();
if (vertexShader != 0) {
gl_AttachShader (program, vertexShader);
gl_AttachShader (program, vertexShader);
}
if (fragmentShader != 0) {
gl_AttachShader (program, fragmentShader);
gl_AttachShader (program, fragmentShader);
}
linkAndCheck (program);
return program;
}
GLuint fgProjectionMatrixIndex;
GLuint fgColorIndex;
GLuint fgVertexIndex;
void initShader(void)
{
const GLsizei vertexShaderLines = sizeof(vertexShaderSource) / sizeof(GLchar*);
@ -257,7 +294,17 @@ void initShader(void)
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");
}
@ -290,12 +337,17 @@ 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);
glColorPointer (numColorComponents, GL_FLOAT, stride, bufferObjectPtr (0));
glVertexPointer(numVertexComponents, GL_FLOAT, stride,
bufferObjectPtr (sizeof(GLfloat) * numColorComponents));
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");
}
@ -339,16 +391,12 @@ void loadOrtho2Df(GLfloat *m, GLfloat l, GLfloat r, GLfloat b, GLfloat t)
void reshape (int w, int h)
{
GLfloat m[16];
glViewport (0, 0, (GLsizei) w, (GLsizei) h);
glMatrixMode (GL_PROJECTION);
if (w <= h) {
loadOrtho2Df (m, 0.0, 30.0, 0.0, 30.0 * (GLfloat) h/(GLfloat) w);
loadOrtho2Df (projectionMatrix, 0.0, 30.0, 0.0, 30.0 * (GLfloat) h/(GLfloat) w);
} else {
loadOrtho2Df (m, 0.0, 30.0 * (GLfloat) w/(GLfloat) h, 0.0, 30.0);
loadOrtho2Df (projectionMatrix, 0.0, 30.0 * (GLfloat) w/(GLfloat) h, 0.0, 30.0);
}
glLoadMatrixf (m);
glMatrixMode (GL_MODELVIEW);
checkError ("reshape");
}