舊版OpenGL紋理立方體

Question

我正在嘗試在舊版OpenGL中紋理長方體。 不管我先渲染長方體的哪一側，都不能像其他所有面一樣正確地對這一面進行正確的紋理化。 我嘗試過先渲染多維數據集的不同面。

這是繪制包含紋理坐標的多維數據集的代碼：

void Objects::cuboidTextured(float width, float height, float depth, float xpos, float ypos, float zpos, float r, float g, float b){
    glMatrixMode(GL_MODELVIEW);

    glPushMatrix();
    glTranslatef(xpos, ypos, zpos);

    glColor3f(r, g, b);

    glBegin(GL_QUADS);
    glVertex3f(  width, -height, depth );
    glTexCoord2f(1,0);
    glVertex3f(  width,  height, depth );
    glTexCoord2f(1,1);
    glVertex3f( -width,  height, depth );
    glTexCoord2f(0,1);
    glVertex3f( -width, -height, depth );
    glTexCoord2f(0,0);
    glEnd();

    glBegin(GL_QUADS);
    glVertex3f( width, -height, -depth );
    glTexCoord2f(1,0);
    glVertex3f( width,  height, -depth );
    glTexCoord2f(1,1);
    glVertex3f( width,  height,  depth );
    glTexCoord2f(0,1);
    glVertex3f( width, -height,  depth );
    glTexCoord2f(0,0);
    glEnd();

    glBegin(GL_QUADS);
    glVertex3f( -width, -height, depth );
    glTexCoord2f(1,0);
    glVertex3f( -width,  height, depth );
    glTexCoord2f(1,1);
    glVertex3f( -width,  height, -depth );
    glTexCoord2f(0,1);
    glVertex3f( -width, -height, -depth );
    glTexCoord2f(0,0);
    glEnd();

    glBegin(GL_QUADS);
    glVertex3f(  width,  height,  depth );
    glTexCoord2f(1,0);
    glVertex3f(  width,  height, -depth );
    glTexCoord2f(1,1);
    glVertex3f( -width,  height, -depth );
    glTexCoord2f(0,1);
    glVertex3f( -width,  height,  depth );
    glTexCoord2f(0,0);
    glEnd();

    glBegin(GL_QUADS);
    glVertex3f(  width, -height, -depth );
    glTexCoord2f(0,1);
    glVertex3f(  width, -height,  depth );
    glTexCoord2f(0,0);
    glVertex3f( -width, -height,  depth );
    glTexCoord2f(1,1);
    glVertex3f( -width, -height, -depth );
    glTexCoord2f(1,0);
    glEnd();

    glBegin(GL_QUADS);
    glVertex3f( -width, -height, -depth);       
    glTexCoord2f(1,0);
    glVertex3f( -width,  height, -depth);      
    glTexCoord2f(1,1);
    glVertex3f(  width,  height, -depth);      
    glTexCoord2f(0,1);
    glVertex3f(  width, -height, -depth); 
    glTexCoord2f(0,0);
    glEnd();

    glPopMatrix();
}

Answer 1

您正在向后做，在glTexCoord()之前調用glVertex() glTexCoord() 。

glVertex ：

glVertex命令用於glBegin / glEnd對中，以指定點，線和面的頂點。 調用glVertex時，當前顏色，法線，紋理坐標和霧坐標與該頂點關聯。

因此，通過glTexCoord()和朋友設置所有頂點狀態， 然后調用glVertex() ：

glBegin(GL_QUADS);
glTexCoord2f(1,0);
glVertex3f( width, -height, -depth );
glTexCoord2f(1,1);
glVertex3f( width,  height, -depth );
glTexCoord2f(0,1);
glVertex3f( width,  height,  depth );
glTexCoord2f(0,0);
glVertex3f( width, -height,  depth );
glEnd();

否則， glVertex()將使用最后設置的任何隨機紋理坐標。