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 /* extension #defines, types and entries, avoiding a dependency on additional
libraries like GLEW or the GL/glext.h header */ 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 #ifndef GL_VERTEX_SHADER
#define GL_VERTEX_SHADER 0x8B31 #define GL_VERTEX_SHADER 0x8B31
#endif #endif
@ -124,6 +132,24 @@ typedef void (*PFNGLGETPROGRAMINFOLOGPROC)
(GLuint program, GLsizei bufSize, GLsizei *length, GLchar *infoLog); (GLuint program, GLsizei bufSize, GLsizei *length, GLchar *infoLog);
PFNGLGETPROGRAMINFOLOGPROC gl_GetProgramInfoLog; 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) void initExtensionEntries(void)
{ {
gl_GenBuffers = (PFNGLGENBUFFERSPROC) glutGetProcAddress ("glGenBuffers"); gl_GenBuffers = (PFNGLGENBUFFERSPROC) glutGetProcAddress ("glGenBuffers");
@ -140,6 +166,11 @@ void initExtensionEntries(void)
gl_GetShaderInfoLog = (PFNGLGETSHADERINFOLOGPROC) glutGetProcAddress ("glGetShaderInfoLog"); gl_GetShaderInfoLog = (PFNGLGETSHADERINFOLOGPROC) glutGetProcAddress ("glGetShaderInfoLog");
gl_GetProgramiv = (PFNGLGETPROGRAMIVPROC) glutGetProcAddress ("glGetProgramiv"); gl_GetProgramiv = (PFNGLGETPROGRAMIVPROC) glutGetProcAddress ("glGetProgramiv");
gl_GetProgramInfoLog = (PFNGLGETPROGRAMINFOLOGPROC) glutGetProcAddress ("glGetProgramInfoLog"); 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 /* 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_GenBuffers (1, &vertexBufferName);
gl_BindBuffer (GL_ARRAY_BUFFER, vertexBufferName); gl_BindBuffer (GL_ARRAY_BUFFER, vertexBufferName);
gl_BufferData (GL_ARRAY_BUFFER, sizeof(varray), varray, GL_STATIC_DRAW); gl_BufferData (GL_ARRAY_BUFFER, sizeof(varray), varray, GL_STATIC_DRAW);
glEnableClientState (GL_COLOR_ARRAY);
glEnableClientState (GL_VERTEX_ARRAY);
checkError ("initBuffer"); checkError ("initBuffer");
} }
const GLchar *vertexShaderSource[] = { 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", "void main(void)\n",
"{\n", "{\n",
" gl_FrontColor = gl_Color;\n", " gl_FrontColor = fg_Color;\n",
" gl_Position = ftransform();\n", " gl_Position = fg_ProjectionMatrix * fg_Vertex;\n",
"}\n" "}\n"
}; };
const GLchar *fragmentShaderSource[] = { const GLchar *fragmentShaderSource[] = {
"#version 120\n", "#version 130\n",
"out vec4 fg_FragColor;\n",
"void main(void)\n", "void main(void)\n",
"{\n", "{\n",
" gl_FragColor = gl_Color;\n", " fg_FragColor = gl_Color;\n",
"}\n" "}\n"
}; };
@ -246,6 +279,10 @@ GLuint createProgram(GLuint vertexShader, GLuint fragmentShader)
return program; return program;
} }
GLuint fgProjectionMatrixIndex;
GLuint fgColorIndex;
GLuint fgVertexIndex;
void initShader(void) void initShader(void)
{ {
const GLsizei vertexShaderLines = sizeof(vertexShaderSource) / sizeof(GLchar*); const GLsizei vertexShaderLines = sizeof(vertexShaderSource) / sizeof(GLchar*);
@ -257,7 +294,17 @@ void initShader(void)
compileShaderSource (GL_FRAGMENT_SHADER, fragmentShaderLines, fragmentShaderSource); compileShaderSource (GL_FRAGMENT_SHADER, fragmentShaderLines, fragmentShaderSource);
GLuint program = createProgram (vertexShader, fragmentShader); GLuint program = createProgram (vertexShader, fragmentShader);
gl_UseProgram (program); 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"); checkError ("initShader");
} }
@ -290,12 +337,17 @@ const GLvoid *bufferObjectPtr (GLsizei index)
return (const GLvoid *) (((char *) NULL) + index); return (const GLvoid *) (((char *) NULL) + index);
} }
GLfloat projectionMatrix[16];
void triangle(void) void triangle(void)
{ {
gl_UniformMatrix4fv (fgProjectionMatrixIndex, 1, GL_FALSE, projectionMatrix);
gl_BindBuffer (GL_ARRAY_BUFFER, vertexBufferName); gl_BindBuffer (GL_ARRAY_BUFFER, vertexBufferName);
glColorPointer (numColorComponents, GL_FLOAT, stride, bufferObjectPtr (0)); gl_VertexAttribPointer (fgColorIndex, numColorComponents, GL_FLOAT, GL_FALSE,
glVertexPointer(numVertexComponents, GL_FLOAT, stride, stride, bufferObjectPtr (0));
bufferObjectPtr (sizeof(GLfloat) * numColorComponents)); gl_VertexAttribPointer (fgVertexIndex, numVertexComponents, GL_FLOAT, GL_FALSE,
stride, bufferObjectPtr (sizeof(GLfloat) * numColorComponents));
glDrawArrays(GL_TRIANGLES, 0, numElements); glDrawArrays(GL_TRIANGLES, 0, numElements);
checkError ("triangle"); checkError ("triangle");
} }
@ -339,16 +391,12 @@ void loadOrtho2Df(GLfloat *m, GLfloat l, GLfloat r, GLfloat b, GLfloat t)
void reshape (int w, int h) void reshape (int w, int h)
{ {
GLfloat m[16];
glViewport (0, 0, (GLsizei) w, (GLsizei) h); glViewport (0, 0, (GLsizei) w, (GLsizei) h);
glMatrixMode (GL_PROJECTION);
if (w <= h) { 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 { } 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"); checkError ("reshape");
} }