OpenGL入门笔记（十五）
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GLvoid COpenGLDemoView::glPrint(GLint x, GLint y, char *string, int set) // Custom GL "Print" Routine
{
if (set>1)
{
set=1;
}
glBindTexture(GL_TEXTURE_2D, texture[0]); // Select Our Font Texture
glDisable(GL_DEPTH_TEST); // Disables Depth Testing
glMatrixMode(GL_PROJECTION); // Select The Projection Matrix
glPushMatrix(); // Store The Projection Matrix
glLoadIdentity(); // Reset The Projection Matrix
glOrtho(0,640,0,480,-1,1); // Set Up An Ortho Screen
glMatrixMode(GL_MODELVIEW); // Select The Modelview Matrix
glPushMatrix(); // Store The Modelview Matrix
glLoadIdentity(); // Reset The Modelview Matrix
glTranslated(x,y,0); // Position The Text (0,0 - Bottom Left)
glListBase(base-32+(128*set)); // Choose The Font Set (0 or 1)
glCallLists(strlen(string),GL_UNSIGNED_BYTE,string);// Write The Text To The Screen
glMatrixMode(GL_PROJECTION); // Select The Projection Matrix
glPopMatrix(); // Restore The Old Projection Matrix
glMatrixMode(GL_MODELVIEW); // Select The Modelview Matrix
glPopMatrix(); // Restore The Old Projection Matrix
glEnable(GL_DEPTH_TEST); // Enables Depth Testing // Pops The Display List Bits
}
GLvoid COpenGLDemoView::BuildFont(GLvoid)
{
float cx; // Holds Our X Character Coord
float cy; // Holds Our Y Character Coord
base=glGenLists(256); // Creating 256 Display Lists
glBindTexture(GL_TEXTURE_2D, texture[0]); // Select Our Font Texture
for (int i =0; i<256; i++) // Loop Through All 256 Lists
{
cx=float(i%16)/16.0f; // X Position Of Current Character
cy=float(i/16)/16.0f; // Y Position Of Current Character
glNewList(base+i,GL_COMPILE); // Start Building A List
glBegin(GL_QUADS); // Use A Quad For Each Character
glTexCoord2f(cx,1-cy-0.0625f); // Texture Coord (Bottom Left)
glVertex2i(0,0); // Vertex Coord (Bottom Left)
glTexCoord2f(cx+0.0625f,1-cy-0.0625f); // Texture Coord (Bottom Right)
glVertex2i(16,0); // Vertex Coord (Bottom Right)
glTexCoord2f(cx+0.0625f,1-cy); // Texture Coord (Top Right)
glVertex2i(16,16); // Vertex Coord (Top Right)
glTexCoord2f(cx,1-cy); // Texture Coord (Top Left)
glVertex2i(0,16); // Vertex Coord (Top Left)
glEnd(); // Done Building Our Quad (Character)
glTranslated(10,0,0); // Move To The Right Of The Character
glEndList(); // Done Building The Display List
} // Loop Until All 256 Are Built
}
int COpenGLDemoView::DrawGLScene()
{// Here's Where We Do All The Drawing
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT); // Clear The Screen And The Depth Buffer
glLoadIdentity(); // Reset The Modelview Matrix
glBindTexture(GL_TEXTURE_2D, texture[1]); // Select Our Second Texture
glTranslatef(0.0f,0.0f,-5.0f); // Move Into The Screen 5 Units
glRotatef(45.0f,0.0f,0.0f,1.0f); // Rotate On The Z Axis 45 Degrees (Clockwise)
glRotatef(cnt1*30.0f,1.0f,1.0f,0.0f); // Rotate On The X & Y Axis By cnt1 (Left To Right)
glDisable(GL_BLEND); // Disable Blending Before We Draw In 3D
glColor3f(1.0f,1.0f,1.0f); // Bright White
glBegin(GL_QUADS); // Draw Our First Texture Mapped Quad
glTexCoord2d(0.0f,0.0f); // First Texture Coord
glVertex2f(-1.0f, 1.0f); // First Vertex
glTexCoord2d(1.0f,0.0f); // Second Texture Coord
glVertex2f( 1.0f, 1.0f); // Second Vertex
glTexCoord2d(1.0f,1.0f); // Third Texture Coord
glVertex2f( 1.0f,-1.0f); // Third Vertex
glTexCoord2d(0.0f,1.0f); // Fourth Texture Coord
glVertex2f(-1.0f,-1.0f); // Fourth Vertex
glEnd(); // Done Drawing The First Quad
glRotatef(90.0f,1.0f,1.0f,0.0f); // Rotate On The X & Y Axis By 90 Degrees (Left To Right)
glBegin(GL_QUADS); // Draw Our Second Texture Mapped Quad
glTexCoord2d(0.0f,0.0f); // First Texture Coord
glVertex2f(-1.0f, 1.0f); // First Vertex
glTexCoord2d(1.0f,0.0f); // Second Texture Coord
glVertex2f( 1.0f, 1.0f); // Second Vertex
glTexCoord2d(1.0f,1.0f); // Third Texture Coord
glVertex2f( 1.0f,-1.0f); // Third Vertex
glTexCoord2d(0.0f,1.0f); // Fourth Texture Coord
glVertex2f(-1.0f,-1.0f); // Fourth Vertex
glEnd(); // Done Drawing Our Second Quad
glEnable(GL_BLEND); // Enable Blending
glLoadIdentity(); // Reset The View
// Pulsing Colors Based On Text Position
glColor3f(1.0f*float(cos(cnt1)),1.0f*float(sin(cnt2)),1.0f-0.5f*float(cos(cnt1+cnt2)));
glPrint(int((280+250*cos(cnt1))),int(235+200*sin(cnt2)),"China",0); // Print GL Text To The Screen
glColor3f(1.0f*float(sin(cnt2)),1.0f-0.5f*float(cos(cnt1+cnt2)),1.0f*float(cos(cnt1)));
glPrint(int((280+230*cos(cnt2))),int(235+200*sin(cnt1)),"OpenGL",1); // Print GL Text To The Screen
glColor3f(0.0f,0.0f,1.0f); // Set Color To Blue
glPrint(int(240+200*cos((cnt2+cnt1)/5)),2,"phinecos",0);
glColor3f(1.0f,1.0f,1.0f); // Set Color To White
glPrint(int(242+200*cos((cnt2+cnt1)/5)),2,"phinecos",0);
return TRUE; // Everything Went OK}
}
BOOL COpenGLDemoView::InitGL(GLvoid) // All Setup For OpenGL Goes Here
{
if (!LoadGLTextures()) // Jump To Texture Loading Routine ( NEW )
{
return FALSE; // If Texture Didn't Load Return FALSE
}
BuildFont(); // Build The Font
glClearColor(0.0f, 0.0f, 0.0f, 0.0f); // Clear The Background Color To Black
glClearDepth(1.0); // Enables Clearing Of The Depth Buffer
glDepthFunc(GL_LEQUAL); // The Type Of Depth Test To Do
glBlendFunc(GL_SRC_ALPHA,GL_ONE); // Select The Type Of Blending
glShadeModel(GL_SMOOTH); // Enables Smooth Color Shading
glEnable(GL_TEXTURE_2D); // Enable 2D Texture Mapping
return TRUE; // Initialization Went OK
}
