NeHeチュートリアルQt実装-lesson 17
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NeHeシリーズチュートリアルの14:2 Dテクスチャフォント
英文教程住所:lesson 17
このレッスンでは、2 Dテクスチャ生成フォントについて説明します.
まず、フォントライブラリの作成および関連文字出力関数です.
次に、フォントテクスチャのロードを行います.
初期化:
描画:
効果図を実行します.
英文教程住所:lesson 17
このレッスンでは、2 Dテクスチャ生成フォントについて説明します.
まず、フォントライブラリの作成および関連文字出力関数です.
namespace {
GLuint texture[2]; // Storage For Our Font Texture
GLuint loop; // Generic Loop Variable
GLfloat cnt1; // 1st Counter Used To Move Text & For Coloring
GLfloat cnt2; // 2nd Counter Used To Move Text & For Coloring
struct FyjBitmapChar
{
QVector<QVector2D> texCoords;
int right; //
int height;//
int ascillValue;
};
struct FyjBitmapFont
{
char *name;
int quality;
FyjBitmapChar *characters;
};
static FyjBitmapChar chars1[128];
static FyjBitmapChar chars2[128];
const FyjBitmapFont font1 = {"standard", 128, chars1};
const FyjBitmapFont font2 = {"Itatic", 128, chars2};
void buildFont()
{
float cx; // Holds Our X Character Coord
float cy; // Holds Our Y Character Coord
glBindTexture(GL_TEXTURE_2D, texture[0]);
for (loop = 0; loop < 256; loop++) {
cx = float(loop%16)/16.0f; // x
cy = float(loop/16)/16.0f; // y
if (loop < 128) {
chars1[loop].texCoords<<QVector2D(cx, cy + 0.0625f)
<<QVector2D(cx+0.0625f, cy+0.0625f)
<<QVector2D(cx+0.0625f, cy)
<<QVector2D(cx, cy);
chars1[loop].height = 16;
chars1[loop].right = 10;
chars1[loop].ascillValue = loop+32;
} else {
chars2[loop-128].texCoords<<QVector2D(cx, cy + 0.0625f)
<<QVector2D(cx+0.0625f, cy+0.0625f)
<<QVector2D(cx+0.0625f, cy)
<<QVector2D(cx, cy);
chars2[loop-128].height = 12;
chars2[loop-128].right = 10;
chars2[loop-128].ascillValue = loop-128+32;
}
}
}
void renderBitmapCharacter(FyjBitmapChar c, int fontSize)
{
Q_ASSERT_X(c.ascillValue >= 32 && c.ascillValue <= 127,
"renderBitmapCharacter", "unspported char");
glEnableClientState(GL_VERTEX_ARRAY);
glEnableClientState(GL_TEXTURE_COORD_ARRAY);
QVector<QVector2D> vertices;
vertices<<QVector2D(0, 0)
<<QVector2D(fontSize, 0)
<<QVector2D(fontSize, fontSize)
<<QVector2D(0, fontSize);
glVertexPointer(2, GL_FLOAT, 0, vertices.constData());
glTexCoordPointer(2, GL_FLOAT, 0, c.texCoords.constData());
glDrawArrays(GL_QUADS, 0, 4);
glDisableClientState(GL_VERTEX_ARRAY);
glDisableClientState(GL_TEXTURE_COORD_ARRAY);
}
void renderBitmapString(GLint x, GLint y, QString string, int set, int fontSize)
{
int numOfReturnChar = 0;
if (string.isNull() || string.isEmpty())
return;
if (set > 1)
set = 1;
FyjBitmapFont currentFont;
if (set == 0)
currentFont = font1;
else
currentFont = font2;
glBindTexture(GL_TEXTURE_2D, texture[0]);
glDisable(GL_DEPTH_TEST);
glMatrixMode(GL_PROJECTION);
glPushMatrix();
glLoadIdentity();
glOrtho(0,640,0,480,-1,1);
glMatrixMode(GL_MODELVIEW);
glPushMatrix();
glLoadIdentity();
glTranslated(x, y, 0);
for(int i = 0; i < string.length(); i++) {
char c = string.at(i).toAscii();
if (c == '
') {
numOfReturnChar++;
glLoadIdentity();
glTranslated(x, y - numOfReturnChar * currentFont.characters[0].height, 0);
continue;
}
renderBitmapCharacter(currentFont.characters[c-32], fontSize);
glTranslated(currentFont.characters[c-32].right * fontSize/16, 0, 0);
}
glMatrixMode(GL_PROJECTION);
glPopMatrix();
glMatrixMode(GL_MODELVIEW);
glPopMatrix();
glEnable(GL_DEPTH_TEST);
}
void glPrint(GLint x, GLint y, int set, int fontSize, const char *fmt, ...)
{
char text[256]; // Holds Our String
va_list ap; // Pointer To List Of Arguments
if (fmt == NULL) // If There's No Text
return; // Do Nothing
va_start(ap, fmt); // Parses The String For Variables
vsprintf(text, fmt, ap); // And Converts Symbols To Actual Numbers
va_end(ap); // Results Are Stored In Text
renderBitmapString(x, y, QString(text), set, fontSize);
}
void drawTextureMappedQuad()
{
QVector<QVector2D> vertices;
QVector<QVector2D> texCoords;
glEnableClientState(GL_VERTEX_ARRAY);
glEnableClientState(GL_TEXTURE_COORD_ARRAY);
vertices<<QVector2D(-1.0f, 1.0f)
<<QVector2D(1.0f, 1.0f)
<<QVector2D(1.0f,-1.0f)
<<QVector2D(-1.0f,-1.0f);
texCoords<<QVector2D(0.0f,0.0f)
<<QVector2D(1.0f,0.0f)
<<QVector2D(1.0f,1.0f)
<<QVector2D(0.0f,1.0f);
glTexCoordPointer(2, GL_FLOAT, 0, texCoords.constData());
glVertexPointer(2, GL_FLOAT, 0, vertices.constData());
glDrawArrays(GL_QUADS, 0, 4);
glDisableClientState(GL_VERTEX_ARRAY);
glDisableClientState(GL_TEXTURE_COORD_ARRAY);
}
}次に、フォントテクスチャのロードを行います.
void MyGLWidget::loadTextures()
{
texture[0] = bindTexture(QString(":/Font.bmp"),
GL_TEXTURE_2D,
GL_RGBA,
QGLContext::LinearFilteringBindOption);
// Create Nearest Filtered Texture
glBindTexture(GL_TEXTURE_2D, texture[0]);
texture[1] = bindTexture(QString(":/Bumps.bmp"),
GL_TEXTURE_2D,
GL_RGBA,
QGLContext::LinearFilteringBindOption);
// Create Linear Filtered Texture
glBindTexture(GL_TEXTURE_2D, texture[1]);
}初期化:
void MyGLWidget::initializeGL()
{
loadTextures();
glEnable(GL_TEXTURE_2D);
buildFont();
glBlendFunc(GL_SRC_ALPHA,GL_ONE);
glShadeModel(GL_SMOOTH); // Enables Smooth Shading
glClearColor(0.0f, 0.0f, 0.0f, 0.0f); // Black Background
glClearDepth(1.0f); // Depth Buffer Setup
glEnable(GL_DEPTH_TEST); // Enables Depth Testing
glDepthFunc(GL_LEQUAL); // The Type Of Depth Test To Do
glHint(GL_PERSPECTIVE_CORRECTION_HINT, GL_NICEST); // Really Nice Perspective Calculations
}描画:
void MyGLWidget::paintGL()
{
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT); // Clear The Screen And The Depth Buffer
glLoadIdentity(); // Reset The Current Modelview Matrix
glBindTexture(GL_TEXTURE_2D, texture[1]);
glTranslatef(0.0f,0.0f,-5.0f);
glRotatef(45.0f,0.0f,0.0f,1.0f);
glRotatef(cnt1*30.0f,1.0f,1.0f,0.0f);
glDisable(GL_BLEND);
glColor3f(1.0f,1.0f,1.0f);
drawTextureMappedQuad();
glRotatef(90.0f,1.0f,1.0f,0.0f);
drawTextureMappedQuad();
glEnable(GL_BLEND);
glLoadIdentity();
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)),0, 16, "NeHe");
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)), 1, 24, "OpenGL");
glColor3f(0.0f,0.0f,1.0f);
glPrint(int(240+200*cos((cnt2+cnt1)/5)),2, 0, 16, "Giuseppe D'Agata");
glColor3f(1.0f,1.0f,1.0f);
glPrint(int(242+200*cos((cnt2+cnt1)/5)),2, 0, 16, "Giuseppe D'Agata");
cnt1+=0.01f;
cnt2+=0.0081f;
}効果図を実行します.