// callback function. 視窗大小改變時會被呼叫, 并傳入新的視窗大小.
void ResizeWindowOpenGL(int width, int height)
{
// 使用新的視窗大小做為新的繪圖解析度
glViewport(0, 0, width, height);
// 投影矩陣, 重設水平跟垂直方向的視角.
float aspect = (float) height / (float) width;
g_fOrthoWidth = g_fOrthoSize;
g_fOrthoHeight = g_fOrthoSize;
if ( aspect > 1.0f )
g_fOrthoHeight *= aspect;
else
g_fOrthoWidth /= aspect;
g_proj_matrix = GutMatrixOrthoRH_OpenGL(g_fOrthoWidth, g_fOrthoHeight, 0.1f, 100.0f);
}
void CGutFontOpenGL::Render(void)
{
if ( m_iNumCharacters==0 )
return;
glPushClientAttrib(GL_CLIENT_VERTEX_ARRAY_BIT);
// 套用字型貼圖
sModelMaterial_OpenGL mtl;
mtl.m_bCullFace = false;
mtl.m_Textures[0] = m_FontTexture;
mtl.Submit(NULL);
// 開啟alpha test
glEnable(GL_ALPHA_TEST);
glAlphaFunc(GL_GREATER, 0.5f);
// 使用平行視角
Matrix4x4 proj_matrix = GutMatrixOrthoRH_OpenGL(m_fWidth, m_fHeight, 0.0f, 1.0f);
Matrix4x4 view_matrix; view_matrix.Identity();
view_matrix[3].Set(-m_fWidth/2.0f, -m_fHeight/2.0f, 0.0f, 1.0f);
// 套用轉換矩陣
glMatrixMode(GL_PROJECTION);
glPushMatrix();
glLoadMatrixf( (float *) &proj_matrix);
glMatrixMode(GL_MODELVIEW);
glPushMatrix();
glLoadMatrixf( (float *) &view_matrix);
// 設定vertex array來源
glEnableClientState(GL_VERTEX_ARRAY);
glEnableClientState(GL_TEXTURE_COORD_ARRAY);
glVertexPointer(3, GL_FLOAT, sizeof(_FontVertex), &m_pVertexArray[0].m_Position);
glTexCoordPointer(2, GL_FLOAT, sizeof(_FontVertex), &m_pVertexArray[0].m_Texcoord);
// 畫出所有文字
glDrawElements(GL_TRIANGLES, m_iNumCharacters * 6, GL_UNSIGNED_SHORT, m_pIndexArray);
glMatrixMode(GL_PROJECTION);
glPopMatrix();
glMatrixMode(GL_MODELVIEW);
glPopMatrix();
glPopClientAttrib();
}
bool InitResourceOpenGL(void)
{
// 投影矩陣
g_proj_matrix = GutMatrixOrthoRH_OpenGL(g_fOrthoWidth, g_fOrthoHeight, 0.1f, 100.0f);
//g_proj_matrix = GutMatrixPerspectiveRH_OpenGL(60.0f, 1.0f, 0.1f, 100.0f);
glMatrixMode(GL_PROJECTION);
glLoadMatrixf( (float *) &g_proj_matrix);
Vector4 a(0.0f, 0.0f, -0.1f, 1.0f);
Vector4 b(0.0f, 0.0f, -100.0f, 1.0f);
Vector4 ta = a * g_proj_matrix;
Vector4 tb = b * g_proj_matrix;
// 載入貼圖
g_Texture0_ID = GutLoadTexture_OpenGL("../../textures/brickwall.tga");
// 套用Trilinear Filter
glBindTexture(GL_TEXTURE_2D, g_Texture0_ID);
glTexParameteri( GL_TEXTURE_2D,GL_TEXTURE_MAG_FILTER, GL_LINEAR );
glTexParameteri( GL_TEXTURE_2D,GL_TEXTURE_MIN_FILTER, GL_LINEAR_MIPMAP_LINEAR );
// 載入貼圖
g_Texture1_ID = GutLoadTexture_OpenGL("../../textures/spotlight_effect.tga");
// 套用Trilinear Filter
glBindTexture(GL_TEXTURE_2D, g_Texture1_ID);
glTexParameteri( GL_TEXTURE_2D,GL_TEXTURE_MAG_FILTER, GL_LINEAR );
glTexParameteri( GL_TEXTURE_2D,GL_TEXTURE_MIN_FILTER, GL_LINEAR_MIPMAP_LINEAR );
glBindTexture(GL_TEXTURE_2D, g_Texture1_ID);
// 把正向跟反向的面都畫出來
glDisable(GL_CULL_FACE);
// 啟動2D貼圖功能
glEnable(GL_TEXTURE_2D);
// 啟動zbuffer隱藏面測試
glEnable(GL_DEPTH_TEST);
return true;
}
void __InitParticleDrawing()
{
srand(0);
m_pParticleVertices = new Vector4[PARTICLE_LINE_NUMBER * 3];
m_pVelocities = new Vector4[PARTICLE_LINE_NUMBER * 3];
for (int i = 0; i < PARTICLE_LINE_NUMBER; ++i)
{
m_pParticleVertices[i].SetX(0);
m_pParticleVertices[i].SetY(0);
m_pParticleVertices[i].SetZ(-1.83);
m_pParticleVertices[i].SetW(1);
m_pVelocities[i].SetX((RANDOM * 2 - 1) * 0.05);
m_pVelocities[i].SetY((RANDOM * 2 - 1) * 0.05);
m_pVelocities[i].SetZ(0.93 + RANDOM * 0.02);
m_pVelocities[i].SetW(1);
}
glClearColor(0.0, 0.0, 0.0, 1.0);
glClearDepth(1.0);
//glEnable(GL_DEPTH_TEST);
glEnable(GL_BLEND);
glDisable(GL_DEPTH_TEST);
glBlendFunc(GL_SRC_ALPHA, GL_ONE);
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
//glEnable(GL_ALPHA_TEST);
glEnable(GL_LINE_SMOOTH);
glColor4f(0.24, 0.51, 0.18, 0.04);
Matrix4x4 view_matrix = Matrix4x4::IdentityMatrix();
//Matrix4x4 view_matrix = GutMatrixLookAtRH(g_eye, g_lookat, g_up);
//Matrix4x4 perspective_matrix = GutMatrixPerspectiveRH_OpenGL(30.0f, g_ratio, 1.0f, 10000.0f);
//Matrix4x4 perspective_matrix = Matrix4x4::IdentityMatrix();
//float fieldOfView = 30.0;
//float aspectRatio = g_ratio;
//float nearPlane = 1.0;
//float farPlane = 10000.0;
//float top = nearPlane * tan(fieldOfView * PI / 360.0);
//float bottom = -1 * top;
//float right = top * aspectRatio;
//float left = -1 * right;
//float a = (right + left) / (right - left);
//float b = (top + bottom) / (top - bottom);
//float c = (farPlane + nearPlane) / (farPlane - nearPlane);
//float d = (2 * farPlane * nearPlane) / (farPlane - nearPlane);
//float x = (2 * nearPlane) / (right - left);
//float y = (2 * nearPlane) / (top - bottom);
//perspective_matrix[0][0] = x;
//perspective_matrix[1][1] = y;
//perspective_matrix[2][2] = c;
//perspective_matrix[3][3] = 0;
//perspective_matrix[2][0] = a;
//perspective_matrix[2][1] = b;
//perspective_matrix[3][2] = d;
//perspective_matrix[2][3] = -1;
Matrix4x4 perspective_matrix = GutMatrixOrthoRH_OpenGL(2, 2, 1, 10000);
Matrix4x4 view_perspective_matrix = view_matrix * perspective_matrix;
glLoadMatrixf((float *) &view_perspective_matrix);
m_bIsTouch = false;
m_fTouchX = 0;
m_fTouchY = 0;
}
// 使用OpenGL來繪圖
void RenderFrameOpenGL(void)
{
// `取得視窗大小`
int w, h;
GutGetWindowSize(w, h);
// `清除畫面`
glClearColor(0.4f, 0.4f, 0.4f, 1.0f);
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
Vector4 camera_lookat(0.0f, 0.0f, 0.0f);
Matrix4x4 ortho_proj = GutMatrixOrthoRH_OpenGL(20.0f, 20.0f, 0.1f, 100.0f);
{
// `前視圖`
glViewport(0, h/2, w/2, h/2);
// view matrix
Vector4 camera_pos(0.0f, -20.0f, 0.0f);
Vector4 camera_up(0.0f, 0.0f, 1.0f);
g_view_matrix = GutMatrixLookAtRH(camera_pos, camera_lookat, camera_up);
// projection matrix
glMatrixMode(GL_PROJECTION);
glLoadMatrixf(&ortho_proj[0][0]);
// render objects
RenderSolarSystemOpenGL();
}
{
// `上視圖`
glViewport(w/2, h/2, w/2, h/2);
// view matrix
Vector4 camera_pos(0.0f, 0.0f, 20.0f);
Vector4 camera_up(0.0f, 1.0f, 0.0f);
g_view_matrix = GutMatrixLookAtRH(camera_pos, camera_lookat, camera_up);
// projection matrix
glMatrixMode(GL_PROJECTION);
glLoadMatrixf(&ortho_proj[0][0]);
// render objects
RenderSolarSystemOpenGL();
}
{
// `右視圖`
glViewport(0, 0, w/2, h/2);
// view matrix
Vector4 camera_pos(20.0f, 0.0f, 0.0f);
Vector4 camera_up(0.0f, 0.0f, 1.0f);
g_view_matrix = GutMatrixLookAtRH(camera_pos, camera_lookat, camera_up);
// projection matrix
glMatrixMode(GL_PROJECTION);
glLoadMatrixf(&ortho_proj[0][0]);
// render objects
RenderSolarSystemOpenGL();
}
{
// `使用者視角`
glViewport(w/2, 0, w/2, h/2);
// object * view matrix
Matrix4x4 object_matrix = g_Control.GetObjectMatrix();
Matrix4x4 view_matrix = g_Control.GetViewMatrix();
g_view_matrix = object_matrix * view_matrix;
// projection matrix
glMatrixMode(GL_PROJECTION);
glLoadMatrixf(&g_projection_matrix[0][0]);
// render objects
RenderSolarSystemOpenGL();
}
{
// `畫出viewport的邊界`
glViewport(0, 0, w, h);
glPushClientAttrib(GL_CLIENT_VERTEX_ARRAY_BIT);
glEnableClientState(GL_VERTEX_ARRAY);
// projection matrix
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
// worldview matrix
glMatrixMode(GL_MODELVIEW);
glLoadIdentity();
// `畫邊界`
glColor4f(1.0f, 1.0f, 1.0f, 1.0f);
glVertexPointer(3, GL_FLOAT, sizeof(Vertex_VC), g_Border);
glDrawArrays(GL_LINES, 0, 4);
glPopClientAttrib();
}
// `把背景backbuffer的畫面呈現出來`
GutSwapBuffersOpenGL();
}