can now also draw the normal vectors (seems very useful for instructive

programs, something which FreeGLUT often gets used for). use the 'n' key
in the shapes demo



git-svn-id: https://svn.code.sf.net/p/freeglut/code/trunk@1403 7f0cb862-5218-0410-a997-914c9d46530a
This commit is contained in:
dcnieho 2012-11-18 15:41:03 +00:00
parent 1f1768f07e
commit 465ff5d0d1
6 changed files with 120 additions and 19 deletions

View File

@ -86,6 +86,8 @@
#define GLUT_SKIP_STALE_MOTION_EVENTS 0x0204 #define GLUT_SKIP_STALE_MOTION_EVENTS 0x0204
#define GLUT_OBJECTS_VISUALIZE_NORMALS 0x0205
/* /*
* New tokens for glutInitDisplayMode. * New tokens for glutInitDisplayMode.
* Only one GLUT_AUXn bit may be used at a time. * Only one GLUT_AUXn bit may be used at a time.

View File

@ -420,6 +420,7 @@ static float ar;
static GLboolean persProject = GL_TRUE; static GLboolean persProject = GL_TRUE;
static GLboolean animateXRot = GL_FALSE; static GLboolean animateXRot = GL_FALSE;
static GLboolean useShader = GL_FALSE; static GLboolean useShader = GL_FALSE;
static GLboolean visNormals = GL_FALSE;
/* /*
* These one-liners draw particular objects, fetching appropriate * These one-liners draw particular objects, fetching appropriate
@ -541,7 +542,7 @@ static const entry table [] =
ENTRY (Sphere), ENTRY (Sphere),
ENTRY (Cone), ENTRY (Cone),
ENTRY (Cylinder), ENTRY (Cylinder),
ENTRY (Cuboctahedron) ENTRY (Cuboctahedron) /* This one doesn't work when in shader mode and is then skipped */
}; };
#undef ENTRY #undef ENTRY
@ -659,6 +660,7 @@ static void display(void)
else else
{ {
/* fixed function pipeline */ /* fixed function pipeline */
glutSetOption(GLUT_OBJECTS_VISUALIZE_NORMALS,visNormals); /* Normals visualized or not? */
glMatrixMode(GL_PROJECTION); glMatrixMode(GL_PROJECTION);
glLoadIdentity(); glLoadIdentity();
if (persProject) if (persProject)
@ -709,6 +711,8 @@ static void display(void)
shapesPrintf (9, 1, "2D rotation (r)"); shapesPrintf (9, 1, "2D rotation (r)");
else else
shapesPrintf (9, 1, "1D rotation (r)"); shapesPrintf (9, 1, "1D rotation (r)");
if (!useShader)
shapesPrintf (10, 1, "visualizing normals: %i (n)",visNormals);
} else { } else {
/* print to command line instead */ /* print to command line instead */
printf ( "Shape %d slides %d stacks %d\n", function_index, slices, stacks ) ; printf ( "Shape %d slides %d stacks %d\n", function_index, slices, stacks ) ;
@ -757,6 +761,9 @@ key(unsigned char key, int x, int y)
case 'S': case 'S':
case 's': useShader=!useShader; break; case 's': useShader=!useShader; break;
case 'N':
case 'n': visNormals=!visNormals; break;
default: default:
break; break;
} }

View File

@ -34,20 +34,24 @@
have a nice code order below */ have a nice code order below */
#ifndef GL_ES_VERSION_2_0 #ifndef GL_ES_VERSION_2_0
static void fghDrawGeometryWire11(GLfloat *vertices, GLfloat *normals, static void fghDrawGeometryWire11(GLfloat *vertices, GLfloat *normals,
GLushort *vertIdxs, GLsizei numParts, GLsizei numVertPerPart, GLenum vertexMode, GLushort *vertIdxs, GLsizei numParts, GLsizei numVertPerPart, GLenum vertexMode,
GLushort *vertIdxs2, GLsizei numParts2, GLsizei numVertPerPart2 GLushort *vertIdxs2, GLsizei numParts2, GLsizei numVertPerPart2
); );
static void fghDrawGeometrySolid11(GLfloat *vertices, GLfloat *normals, GLsizei numVertices, static void fghDrawGeometrySolid11(GLfloat *vertices, GLfloat *normals, GLsizei numVertices,
GLushort *vertIdxs, GLsizei numParts, GLsizei numVertIdxsPerPart); GLushort *vertIdxs, GLsizei numParts, GLsizei numVertIdxsPerPart);
#endif #endif
static void fghDrawGeometryWire20(GLfloat *vertices, GLfloat *normals, GLsizei numVertices, static void fghDrawGeometryWire20(GLfloat *vertices, GLfloat *normals, GLsizei numVertices,
GLushort *vertIdxs, GLsizei numParts, GLsizei numVertPerPart, GLenum vertexMode, GLushort *vertIdxs, GLsizei numParts, GLsizei numVertPerPart, GLenum vertexMode,
GLushort *vertIdxs2, GLsizei numParts2, GLsizei numVertPerPart2, GLushort *vertIdxs2, GLsizei numParts2, GLsizei numVertPerPart2,
GLint attribute_v_coord, GLint attribute_v_normal GLint attribute_v_coord, GLint attribute_v_normal
); );
static void fghDrawGeometrySolid20(GLfloat *vertices, GLfloat *normals, GLsizei numVertices, static void fghDrawGeometrySolid20(GLfloat *vertices, GLfloat *normals, GLsizei numVertices,
GLushort *vertIdxs, GLsizei numParts, GLsizei numVertIdxsPerPart, GLushort *vertIdxs, GLsizei numParts, GLsizei numVertIdxsPerPart,
GLint attribute_v_coord, GLint attribute_v_normal); GLint attribute_v_coord, GLint attribute_v_normal);
/* declare function for generating visualization of normals */
static void fghGenerateNormalVisualization(GLfloat *vertices, GLfloat *normals, GLsizei numVertices,
GLushort *vertIdxs, GLsizei numParts, GLsizei numVertIdxsPerPart);
static void fghDrawNormalVisualization();
/* Drawing geometry: /* Drawing geometry:
* Explanation of the functions has to be separate for the polyhedra and * Explanation of the functions has to be separate for the polyhedra and
@ -116,8 +120,8 @@ static void fghDrawGeometrySolid20(GLfloat *vertices, GLfloat *normals, GLsizei
* Feel free to contribute better naming ;) * Feel free to contribute better naming ;)
*/ */
static void fghDrawGeometryWire(GLfloat *vertices, GLfloat *normals, GLsizei numVertices, static void fghDrawGeometryWire(GLfloat *vertices, GLfloat *normals, GLsizei numVertices,
GLushort *vertIdxs, GLsizei numParts, GLsizei numVertPerPart, GLenum vertexMode, GLushort *vertIdxs, GLsizei numParts, GLsizei numVertPerPart, GLenum vertexMode,
GLushort *vertIdxs2, GLsizei numParts2, GLsizei numVertPerPart2 GLushort *vertIdxs2, GLsizei numParts2, GLsizei numVertPerPart2
) )
{ {
GLint attribute_v_coord = fgStructure.CurrentWindow->Window.attribute_v_coord; GLint attribute_v_coord = fgStructure.CurrentWindow->Window.attribute_v_coord;
@ -176,8 +180,19 @@ static void fghDrawGeometrySolid(GLfloat *vertices, GLfloat *normals, GLsizei nu
attribute_v_coord, attribute_v_normal); attribute_v_coord, attribute_v_normal);
#ifndef GL_ES_VERSION_2_0 #ifndef GL_ES_VERSION_2_0
else else
{
fghDrawGeometrySolid11(vertices, normals, numVertices, fghDrawGeometrySolid11(vertices, normals, numVertices,
vertIdxs, numParts, numVertIdxsPerPart); vertIdxs, numParts, numVertIdxsPerPart);
if (fgStructure.CurrentWindow->State.VisualizeNormals)
{
/* generate normals for each vertex to be drawn as well */
fghGenerateNormalVisualization(vertices, normals, numVertices,
vertIdxs, numParts, numVertIdxsPerPart);
/* draw normals for each vertex as well */
fghDrawNormalVisualization();
}
}
#endif #endif
} }
@ -186,8 +201,8 @@ static void fghDrawGeometrySolid(GLfloat *vertices, GLfloat *normals, GLsizei nu
/* Version for OpenGL (ES) 1.1 */ /* Version for OpenGL (ES) 1.1 */
#ifndef GL_ES_VERSION_2_0 #ifndef GL_ES_VERSION_2_0
static void fghDrawGeometryWire11(GLfloat *vertices, GLfloat *normals, static void fghDrawGeometryWire11(GLfloat *vertices, GLfloat *normals,
GLushort *vertIdxs, GLsizei numParts, GLsizei numVertPerPart, GLenum vertexMode, GLushort *vertIdxs, GLsizei numParts, GLsizei numVertPerPart, GLenum vertexMode,
GLushort *vertIdxs2, GLsizei numParts2, GLsizei numVertPerPart2 GLushort *vertIdxs2, GLsizei numParts2, GLsizei numVertPerPart2
) )
{ {
int i; int i;
@ -217,7 +232,7 @@ static void fghDrawGeometryWire11(GLfloat *vertices, GLfloat *normals,
static void fghDrawGeometrySolid11(GLfloat *vertices, GLfloat *normals, GLsizei numVertices, static void fghDrawGeometrySolid11(GLfloat *vertices, GLfloat *normals, GLsizei numVertices,
GLushort *vertIdxs, GLsizei numParts, GLsizei numVertIdxsPerPart) GLushort *vertIdxs, GLsizei numParts, GLsizei numVertIdxsPerPart)
{ {
int i; int i;
@ -243,10 +258,9 @@ static void fghDrawGeometrySolid11(GLfloat *vertices, GLfloat *normals, GLsizei
/* Version for OpenGL (ES) >= 2.0 */ /* Version for OpenGL (ES) >= 2.0 */
static void fghDrawGeometryWire20(GLfloat *vertices, GLfloat *normals, GLsizei numVertices, static void fghDrawGeometryWire20(GLfloat *vertices, GLfloat *normals, GLsizei numVertices,
GLushort *vertIdxs, GLsizei numParts, GLsizei numVertPerPart, GLenum vertexMode, GLushort *vertIdxs, GLsizei numParts, GLsizei numVertPerPart, GLenum vertexMode,
GLushort *vertIdxs2, GLsizei numParts2, GLsizei numVertPerPart2, GLushort *vertIdxs2, GLsizei numParts2, GLsizei numVertPerPart2,
GLint attribute_v_coord, GLint attribute_v_normal GLint attribute_v_coord, GLint attribute_v_normal)
)
{ {
GLuint vbo_coords = 0, vbo_normals = 0, GLuint vbo_coords = 0, vbo_normals = 0,
ibo_elements = 0, ibo_elements2 = 0; ibo_elements = 0, ibo_elements2 = 0;
@ -446,6 +460,71 @@ static void fghDrawGeometrySolid20(GLfloat *vertices, GLfloat *normals, GLsizei
/**
* Generate vertex indices for visualizing the normals.
*/
static GLfloat *verticesForNormalVisualization;
static GLushort numNormalVertices = 0;
static void fghGenerateNormalVisualization(GLfloat *vertices, GLfloat *normals, GLsizei numVertices,
GLushort *vertIdxs, GLsizei numParts, GLsizei numVertIdxsPerPart)
{
GLushort i,j;
/* calc number of vertices to generate, allocate. TODO: FREE again after draw!
* two for each vertex in the input shape
*/
if (!vertIdxs)
numNormalVertices = numVertices * 2;
else
numNormalVertices = numParts * numVertIdxsPerPart * 2;
verticesForNormalVisualization = malloc(numNormalVertices*3 * sizeof(GLfloat));
/* Now generate vertices for lines to draw the normals */
if (!vertIdxs)
{
for (i=0,j=0; i<numNormalVertices*3/2; i+=3, j+=6)
{
verticesForNormalVisualization[j+0] = vertices[i+0];
verticesForNormalVisualization[j+1] = vertices[i+1];
verticesForNormalVisualization[j+2] = vertices[i+2];
verticesForNormalVisualization[j+3] = vertices[i+0] + normals[i+0]/4.f;
verticesForNormalVisualization[j+4] = vertices[i+1] + normals[i+1]/4.f;
verticesForNormalVisualization[j+5] = vertices[i+2] + normals[i+2]/4.f;
}
}
else
{
for (i=0,j=0; i<numNormalVertices/2; i++, j+=6)
{
GLushort idx = vertIdxs[i]*3;
verticesForNormalVisualization[j+0] = vertices[idx+0];
verticesForNormalVisualization[j+1] = vertices[idx+1];
verticesForNormalVisualization[j+2] = vertices[idx+2];
verticesForNormalVisualization[j+3] = vertices[idx+0] + normals[idx+0]/4.f;
verticesForNormalVisualization[j+4] = vertices[idx+1] + normals[idx+1]/4.f;
verticesForNormalVisualization[j+5] = vertices[idx+2] + normals[idx+2]/4.f;
}
}
}
static void fghDrawNormalVisualization()
{
GLfloat currentColor[4];
/* Setup draw color: (1,1,1)-shape's color */
glGetFloatv(GL_CURRENT_COLOR,currentColor);
glColor4f(1-currentColor[0],1-currentColor[1],1-currentColor[2],currentColor[3]);
glEnableClientState(GL_VERTEX_ARRAY);
glVertexPointer(3, GL_FLOAT, 0, verticesForNormalVisualization);
glDrawArrays(GL_LINES, 0, numNormalVertices);
glDisableClientState(GL_VERTEX_ARRAY);
/* Done, free memory, reset color */
free(verticesForNormalVisualization);
glColor4fv(currentColor);
}
/** /**
* Generate all combinations of vertices and normals needed to draw object. * Generate all combinations of vertices and normals needed to draw object.
* Optional shape decomposition to triangles: * Optional shape decomposition to triangles:

View File

@ -402,7 +402,9 @@ struct tagSFG_WindowState
GLboolean IsFullscreen; /* is the window fullscreen? */ GLboolean IsFullscreen; /* is the window fullscreen? */
GLboolean NeedToInitContext; /* are OpenGL context/resources loaded? */ GLboolean NeedToInitContext; /* are OpenGL context/resources loaded? */
GLboolean VisualizeNormals; /* When drawing objects, draw vectors representing the normals as well? */
}; };

View File

@ -115,6 +115,11 @@ void FGAPIENTRY glutSetOption( GLenum eWhat, int value )
fgState.SkipStaleMotion = value; fgState.SkipStaleMotion = value;
break; break;
case GLUT_OBJECTS_VISUALIZE_NORMALS:
if( fgStructure.CurrentWindow != NULL )
fgStructure.CurrentWindow->State.VisualizeNormals = value;
break;
default: default:
fgWarning( "glutSetOption(): missing enum handle %d", eWhat ); fgWarning( "glutSetOption(): missing enum handle %d", eWhat );
break; break;
@ -205,6 +210,11 @@ int FGAPIENTRY glutGet( GLenum eWhat )
case GLUT_SKIP_STALE_MOTION_EVENTS: case GLUT_SKIP_STALE_MOTION_EVENTS:
return fgState.SkipStaleMotion; return fgState.SkipStaleMotion;
case GLUT_OBJECTS_VISUALIZE_NORMALS:
if( fgStructure.CurrentWindow == NULL )
return GL_FALSE;
return fgStructure.CurrentWindow->State.VisualizeNormals;
default: default:
return fgPlatformGlutGet ( eWhat ); return fgPlatformGlutGet ( eWhat );
break; break;

View File

@ -98,6 +98,7 @@ SFG_Window* fgCreateWindow( SFG_Window* parent, const char* title,
window->State.IgnoreKeyRepeat = GL_FALSE; window->State.IgnoreKeyRepeat = GL_FALSE;
window->State.KeyRepeating = GL_FALSE; window->State.KeyRepeating = GL_FALSE;
window->State.IsFullscreen = GL_FALSE; window->State.IsFullscreen = GL_FALSE;
window->State.VisualizeNormals= GL_FALSE;
/* /*
* Open the window now. The fgOpenWindow() function is system * Open the window now. The fgOpenWindow() function is system