void display() {
glClear(GL_COLOR_BUFFER_BIT);
glRasterPos2i(0, 0);
glDrawPixels(checkImageWidth, checkImageHeight, GL_RGB, GL_UNSIGNED_BYTE, checkImage);
int i;
GLushort values[histogram_size][3];
glGetHistogram(GL_HISTOGRAM, GL_TRUE, GL_RGB, GL_UNSIGNED_SHORT, values);
glBegin(GL_LINE_STRIP);
glColor3f(1.0, 0.0, 0.0);
for (i = 0; i < histogram_size; i++)
glVertex2s(i, values[i][0]);
glEnd();
glBegin(GL_LINE_STRIP);
glColor3f(0.0, 1.0, 0.0);
for (i = 0; i < histogram_size; i++)
glVertex2s(i, values[i][1]);
glEnd();
glBegin(GL_LINE_STRIP);
glColor3f(0.0, 0.0, 1.0);
for (i = 0; i < histogram_size; i++)
glVertex2s(i, values[i][2]);
glEnd();
glFlush();
}
void display(void)
{
int i;
GLushort values[HISTOGRAM_SIZE][3];
glClear(GL_COLOR_BUFFER_BIT);
glRasterPos2i(1, 1);
glDrawPixels(width, height, GL_RGB, GL_UNSIGNED_BYTE, pixels);
glGetHistogram(GL_HISTOGRAM, GL_TRUE, GL_RGB, GL_UNSIGNED_SHORT, values);
/* Plot histogram */
glBegin(GL_LINE_STRIP);
glColor3f(1.0, 0.0, 0.0);
for ( i = 0; i < HISTOGRAM_SIZE; i++ )
glVertex2s(i, values[i][0]);
glEnd();
glBegin(GL_LINE_STRIP);
glColor3f(0.0, 1.0, 0.0);
for ( i = 0; i < HISTOGRAM_SIZE; i++ )
glVertex2s(i, values[i][1]);
glEnd();
glBegin(GL_LINE_STRIP);
glColor3f(0.0, 0.0, 1.0);
for ( i = 0; i < HISTOGRAM_SIZE; i++ )
glVertex2s(i, values[i][2]);
glEnd();
glFlush();
}
static int
GetHistogram(__GLXclientState * cl, GLbyte * pc, GLXContextTag tag)
{
GLint compsize;
GLenum format, type, target;
GLboolean swapBytes, reset;
__GLXcontext *cx;
ClientPtr client = cl->client;
int error;
__GLX_DECLARE_SWAP_VARIABLES;
char *answer, answerBuffer[200];
GLint width = 0;
xGLXSingleReply reply = { 0, };
cx = __glXForceCurrent(cl, tag, &error);
if (!cx) {
return error;
}
__GLX_SWAP_INT(pc + 0);
__GLX_SWAP_INT(pc + 4);
__GLX_SWAP_INT(pc + 8);
format = *(GLenum *) (pc + 4);
type = *(GLenum *) (pc + 8);
target = *(GLenum *) (pc + 0);
swapBytes = *(GLboolean *) (pc + 12);
reset = *(GLboolean *) (pc + 13);
glGetHistogramParameteriv(target, GL_HISTOGRAM_WIDTH, &width);
/*
* The one query above might fail if we're in a state where queries
* are illegal, but then width would still be zero anyway.
*/
compsize = __glGetTexImage_size(target, 1, format, type, width, 1, 1);
if (compsize < 0)
return BadLength;
glPixelStorei(GL_PACK_SWAP_BYTES, !swapBytes);
__GLX_GET_ANSWER_BUFFER(answer, cl, compsize, 1);
__glXClearErrorOccured();
glGetHistogram(target, reset, format, type, answer);
if (__glXErrorOccured()) {
__GLX_BEGIN_REPLY(0);
__GLX_SWAP_REPLY_HEADER();
}
else {
__GLX_BEGIN_REPLY(compsize);
__GLX_SWAP_REPLY_HEADER();
__GLX_SWAP_INT(&width);
((xGLXGetHistogramReply *) &reply)->width = width;
__GLX_SEND_VOID_ARRAY(compsize);
}
return Success;
}
JNIEXPORT void JNICALL Java_org_lwjgl_opengl_ARBImaging_nglGetHistogramBO(JNIEnv *env, jclass clazz, jint target, jboolean reset, jint format, jint type, jlong values_buffer_offset, jlong function_pointer) {
GLvoid *values_address = (GLvoid *)(intptr_t)offsetToPointer(values_buffer_offset);
glGetHistogramPROC glGetHistogram = (glGetHistogramPROC)((intptr_t)function_pointer);
glGetHistogram(target, reset, format, type, values_address);
}
///////////////////////////////////////////////////////////////////////
// Called to draw scene
void RenderScene(void)
{
GLint i; // Looping variable
GLint iViewport[4]; // Viewport
GLint iLargest; // Largest histogram value
static GLubyte invertTable[256][3];// Inverted color table
// Do a black and white scaling
static GLfloat lumMat[16] = { 0.30f, 0.30f, 0.30f, 0.0f,
0.59f, 0.59f, 0.59f, 0.0f,
0.11f, 0.11f, 0.11f, 0.0f,
0.0f, 0.0f, 0.0f, 1.0f };
static GLfloat mSharpen[3][3] = { // Sharpen convolution kernel
{0.0f, -1.0f, 0.0f},
{-1.0f, 5.0f, -1.0f },
{0.0f, -1.0f, 0.0f }};
static GLfloat mEmboss[3][3] = { // Emboss convolution kernel
{ 2.0f, 0.0f, 0.0f },
{ 0.0f, -1.0f, 0.0f },
{ 0.0f, 0.0f, -1.0f }};
static GLint histoGram[256]; // Storeage for histogram statistics
// Clear the window with current clearing color
glClear(GL_COLOR_BUFFER_BIT);
// Current Raster Position always at bottom left hand corner of window
glRasterPos2i(0, 0);
glGetIntegerv(GL_VIEWPORT, iViewport);
glPixelZoom((GLfloat) iViewport[2] / (GLfloat)iWidth, (GLfloat) iViewport[3] / (GLfloat)iHeight);
if(bHistogram == GL_TRUE) // Collect Historgram data
{
// We are collecting luminance data, use our conversion formula
// instead of OpenGL's (which just adds color components together)
glMatrixMode(GL_COLOR);
glLoadMatrixf(lumMat);
glMatrixMode(GL_MODELVIEW);
// Start collecting histogram data, 256 luminance values
glHistogram(GL_HISTOGRAM, 256, GL_LUMINANCE, GL_FALSE);
glEnable(GL_HISTOGRAM);
}
// Do image operation, depending on rendermode index
switch(iRenderMode)
{
case 5: // Sharpen image
glConvolutionFilter2D(GL_CONVOLUTION_2D, GL_RGB, 3, 3, GL_LUMINANCE, GL_FLOAT, mSharpen);
glEnable(GL_CONVOLUTION_2D);
break;
case 4: // Emboss image
glConvolutionFilter2D(GL_CONVOLUTION_2D, GL_RGB, 3, 3, GL_LUMINANCE, GL_FLOAT, mEmboss);
glEnable(GL_CONVOLUTION_2D);
glMatrixMode(GL_COLOR);
glLoadMatrixf(lumMat);
glMatrixMode(GL_MODELVIEW);
break;
case 3: // Invert Image
for(i = 0; i < 255; i++)
{
invertTable[i][0] = (GLubyte)(255 - i);
invertTable[i][1] = (GLubyte)(255 - i);
invertTable[i][2] = (GLubyte)(255 - i);
}
glColorTable(GL_COLOR_TABLE, GL_RGB, 256, GL_RGB, GL_UNSIGNED_BYTE, invertTable);
glEnable(GL_COLOR_TABLE);
break;
case 2: // Brighten Image
glMatrixMode(GL_COLOR);
glScalef(1.25f, 1.25f, 1.25f);
glMatrixMode(GL_MODELVIEW);
break;
case 1: // Just do a plain old image copy
default:
// This line intentially left blank
break;
}
// Do the pixel draw
glDrawPixels(iWidth, iHeight, eFormat, GL_UNSIGNED_BYTE, pImage);
// Fetch and draw histogram?
if(bHistogram == GL_TRUE)
{
// Read histogram data into buffer
glGetHistogram(GL_HISTOGRAM, GL_TRUE, GL_LUMINANCE, GL_INT, histoGram);
// Find largest value for scaling graph down
iLargest = 0;
for(i = 0; i < 255; i++)
if(iLargest < histoGram[i])
iLargest = histoGram[i];
// White lines
glColor3f(1.0f, 1.0f, 1.0f);
glBegin(GL_LINE_STRIP);
for(i = 0; i < 255; i++)
glVertex2f((GLfloat)i, (GLfloat)histoGram[i] / (GLfloat) iLargest * 128.0f);
glEnd();
bHistogram = GL_FALSE;
glDisable(GL_HISTOGRAM);
}
// Reset everyting to default
glMatrixMode(GL_COLOR);
glLoadIdentity();
glMatrixMode(GL_MODELVIEW);
glDisable(GL_CONVOLUTION_2D);
glDisable(GL_COLOR_TABLE);
// Show our hard work...
glutSwapBuffers();
}
