outdated: 29.Blitter Function, RAW Texture Loading
2024-06-04 21:22:57
在这篇中两个点。
一个是raw格式图片的贴图：
int ReadTextureData(char* filename, P_TEXTURE_IMAGE buffer)
{FILE* f;int done = 0;int stride = buffer->width * buffer->format;unsigned char* p = NULL;f = fopen(filename, "rb");if (f != NULL) {for (int i = buffer->height - 1; i >= 0; --i) {p = buffer->data + (i * stride);for (int j = 0; j < buffer->width; ++j) {for (int k = 0; k < buffer->format - 1; ++k, ++p, ++done) {*p = fgetc(f);}*p = 255;++p;}}fclose(f);}else {MessageBox(NULL, "Unable To Open Image File", "IMAGE ERROR", MB_OK | MB_ICONINFORMATION);}return done;
}一个双重贴图即部分覆盖，图像数据，以及两个贴图的开始部分，范围以及模式是重点：
// Copy any section of a (src) texture and paste it into a destination (dst) texture
void Blit(P_TEXTURE_IMAGE src, P_TEXTURE_IMAGE dst, int src_xstart, int src_ystart, int src_width,int src_height, int dst_xstart, int dst_ystart, int blend, int alpha)
{unsigned char* s;unsigned char* d; // Source and destination// Clamp alpha if value is out of rangeif (alpha > 255) alpha = 255;if (alpha < 0) alpha = 0;// Check for incorrect blend flag valuesif (blend < 0) blend = 0;if (blend > 1) blend = 1;// Start row-dst (row * width in pixel * bytes per pixel)d = dst->data + (dst_ystart * dst->width * dst->format);s = src->data + (src_ystart * src->width * src->format);// Start row-src (row * width in pixel * bytes per pixel)for (int i = 0; i < src_height; ++i) { s = s + (src_xstart * src->format); // Move through src data by bytes per pixeld = d + (dst_xstart * dst->format); // Move through dst data by bytes per pixelfor (int j = 0; j < src_width; ++j) {for (int k = 0; k < src->format; ++k, ++s, ++d) {if (blend) {// Multiply src data*alpha add dst data(255-alpha)*d = ((*s * alpha) + (*d * (255 - alpha))) >> 8;}else { // Keep in 0-255 range with >> 8*d = *s; // No blending just do a straight copy
}}}d = d + (dst->width - (src_width + dst_xstart)) * dst->format;s = s + (src->width - (src_width + src_xstart)) * src->format;}
}
下面为代码，同样修改部分位于双行星号内。
1 /******************************************************************************************************************************************/
2 /******************************************************************************************************************************************/
3 #include <windows.h>
4 #include <math.h>
5 #include <stdio.h>
6 #include <gl/glew.h>
7 #include <GL\glut.h>
8 #include <GL/GLUAX.H>
9 #pragma comment(lib, "legacy_stdio_definitions.lib")
10
11 /*
12 * Every OpenGL program is linked to a Rendering Context.
13 * A Rendering Context is what links OpenGL calls to the Device Context.
14 * In order for your program to draw to a Window you need to create a Device Context.
15 * The DC connects the Window to the GDI (Graphics Device Interface).
16 */
17
18 HGLRC hRC = NULL; // Permanent rendering context
19 HDC hDC = NULL; // Private GDI device context
20 HWND hWnd = NULL; // Holds our window handle
21 HINSTANCE hInstance; // Holds the instance of the application
22
23 /*
24 * It's important to make this global so that each procedure knows if
25 * the program is running in fullscreen mode or not.
26 */
27
28 bool keys[256]; // Array used for the keyboard routine
29 bool active = TRUE; // Window active flag set to TRUE by default
30 bool fullscreen = TRUE; // Fullscreen flag set to fullscreen mode by default
31
32 DEVMODE DMsaved; // Saves the previous sacreen settings
33
34 GLfloat xrot;
35 GLfloat yrot;
36 GLfloat zrot;
37
38 GLuint texture[1];
39
40 typedef struct Texture_Image {
41 int width;
42 int height;
43 int format; // Number of bytes per pixel
44 unsigned char* data;
45 } TEXTURE_IMAGE;
46
47 typedef TEXTURE_IMAGE* P_TEXTURE_IMAGE;
48
49 P_TEXTURE_IMAGE t1;
50 P_TEXTURE_IMAGE t2;
51
52
53 LRESULT CALLBACK WndProc(HWND, UINT, WPARAM, LPARAM); // Declaration for WndProc
54
55 P_TEXTURE_IMAGE AllocateTextureBuffer(GLint w, GLint h, GLint f)
56 {
57 P_TEXTURE_IMAGE ti = NULL;
58 unsigned char* c = NULL; // Pointer to block memory for image
59
60 ti = (P_TEXTURE_IMAGE)malloc(sizeof(TEXTURE_IMAGE));
61 if (ti != NULL) {
62 ti->width = w;
63 ti->height = h;
64 ti->format = f;
65 c = (unsigned char*)malloc(w * h * f);
66 if (c != NULL) {
67 ti->data = c;
68 }
69 else {
70 MessageBox(NULL, "Could Not Allocate Memory For A Texture Buffer", "BUFFER ERROR", MB_OK |
71 MB_ICONINFORMATION);
72 return NULL;
73 }
74 }
75 else {
76 MessageBox(NULL, "Could Not Allocate An Image Structure", "IMAGE STRUCTURE ERROR", MB_OK |
77 MB_ICONINFORMATION);
78 return NULL;
79 }
80 return ti;
81 }
82
83 void DeallocateTexture(P_TEXTURE_IMAGE t)
84 {
85 if (t) {
86 if (t->data) {
87 free(t->data);
88 }
89 free(t);
90 }
91 }
92
93 int ReadTextureData(char* filename, P_TEXTURE_IMAGE buffer)
94 {
95 FILE* f;
96 int done = 0;
97 int stride = buffer->width * buffer->format;
98 unsigned char* p = NULL;
99
100 f = fopen(filename, "rb");
101 if (f != NULL) {
102 for (int i = buffer->height - 1; i >= 0; --i) {
103 p = buffer->data + (i * stride);
104 for (int j = 0; j < buffer->width; ++j) {
105 for (int k = 0; k < buffer->format - 1; ++k, ++p, ++done) {
106 *p = fgetc(f);
107 }
108 *p = 255;
109 ++p;
110 }
111 }
112 fclose(f);
113 }
114 else {
115 MessageBox(NULL, "Unable To Open Image File", "IMAGE ERROR", MB_OK | MB_ICONINFORMATION);
116 }
117 return done;
118 }
119
120 void BuildTexture(P_TEXTURE_IMAGE tex)
121 {
122 glGenTextures(1, &texture[0]);
123 glBindTexture(GL_TEXTURE_2D, texture[0]);
124 glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
125 glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
126 gluBuild2DMipmaps(GL_TEXTURE_2D, GL_RGB, tex->width, tex->height, GL_RGBA, GL_UNSIGNED_BYTE,
127 tex->data);
128 }
129 // Copy any section of a (src) texture and paste it into a destination (dst) texture
130 void Blit(P_TEXTURE_IMAGE src, P_TEXTURE_IMAGE dst, int src_xstart, int src_ystart, int src_width,
131 int src_height, int dst_xstart, int dst_ystart, int blend, int alpha)
132 {
133 unsigned char* s;
134 unsigned char* d; // Source and destination
135
136 // Clamp alpha if value is out of range
137 if (alpha > 255) alpha = 255;
138 if (alpha < 0) alpha = 0;
139 // Check for incorrect blend flag values
140 if (blend < 0) blend = 0;
141 if (blend > 1) blend = 1;
142 // Start row-dst (row * width in pixel * bytes per pixel)
143 d = dst->data + (dst_ystart * dst->width * dst->format);
144 s = src->data + (src_ystart * src->width * src->format);
145 // Start row-src (row * width in pixel * bytes per pixel)
146 for (int i = 0; i < src_height; ++i) {
147 s = s + (src_xstart * src->format); // Move through src data by bytes per pixel
148 d = d + (dst_xstart * dst->format); // Move through dst data by bytes per pixel
149 for (int j = 0; j < src_width; ++j) {
150 for (int k = 0; k < src->format; ++k, ++s, ++d) {
151 if (blend) {
152 // Multiply src data*alpha add dst data(255-alpha)
153 *d = ((*s * alpha) + (*d * (255 - alpha))) >> 8;
154 }
155 else { // Keep in 0-255 range with >> 8
156 *d = *s; // No blending just do a straight copy
157 }
158 }
159 }
160 d = d + (dst->width - (src_width + dst_xstart)) * dst->format;
161 s = s + (src->width - (src_width + src_xstart)) * src->format;
162 }
163 }
164 /******************************************************************************************************************************************/
165 /******************************************************************************************************************************************/
166 GLvoid ReSizeGLScene(GLsizei width, GLsizei height) // Resize and initialize the GL window
167 {
168 if (height == 0) { // Prevent a divide by zero by
169 height = 1; // Making height equal one
170 }
171
172 glViewport(0, 0, width, height); // Reset the current viewport
173
174 /*
175 * The following lines set the screen up for a perspective view.
176 * Meaning things in the distance get smaller. This creates a realistic looking scene.
177 * The perspective is calculated with a 45 degree viewing angle based on
178 * the windows width and height. The 0.1f, 100.0f is the starting point and
179 * ending point for how deep we can draw into the screen.
180 *
181 * The projection matrix is responsible for adding perspective to our scene.
182 * glLoadIdentity() restores the selected matrix to it's original state.
183 * The modelview matrix is where our object information is stored.
184 * Lastly we reset the modelview matrix.
185 */
186
187 glMatrixMode(GL_PROJECTION); // Select the projection matrix
188 glLoadIdentity(); // Reset the projection matrix
189
190 // Calculate the aspect ratio of the window
191 gluPerspective(45.0f, (GLfloat)width / (GLfloat)height, 0.1f, 100.0f);
192 // glOrtho(0.0f, width, height, 0.0f, -1.0f, 1.0f); // Create orhto 640X480 view (0, 0, at the top)
193
194 glMatrixMode(GL_MODELVIEW); // Seclet the modelview matrix
195 glLoadIdentity(); // Reset the modelview matrix
196 }
197 /******************************************************************************************************************************************/
198 /******************************************************************************************************************************************/
199
200 int InitGL(GLvoid) // All setup for OpenGL goes here
201 {
202 t1 = AllocateTextureBuffer(256, 256, 4);
203 if (ReadTextureData("Data/Monitor.raw", t1) == 0) {
204 MessageBox(NULL, "Could Not Read 'Monitor.raw' Image Data", "TEXTURE ERROR", MB_OK | MB_ICONINFORMATION);
205 return false;
206 }
207 t2 = AllocateTextureBuffer(256, 256, 4);
208 if (ReadTextureData("Data/GL.raw", t2) == 0) {
209 MessageBox(NULL, "Could Not Read 'GL.raw' Image Data", "TEXTURE ERROR", MB_OK | MB_ICONINFORMATION);
210 return false;
211 }
212
213 // Image to blend in, original image, src start X & Y, src width & height,
214 // dst location X & Y, blend flag, alpha value
215 Blit(t2, t1, 127, 127, 128, 128, 64, 64, 1, 127);
216
217 BuildTexture(t1);
218
219 DeallocateTexture(t1);
220 DeallocateTexture(t2);
221
222 glEnable(GL_TEXTURE_2D);
223 glShadeModel(GL_SMOOTH);
224 glClearColor(0.0f, 0.0f, 0.0f, 0.0f); // Background
225 glClearDepth(1.0f); // Depth buffer setup
226 glEnable(GL_DEPTH_TEST);
227 glDepthFunc(GL_LESS);
228
229 return TRUE;
230 }
231
232 /*
233 * For now all we will do is clear the screen to the color we previously decided on,
234 * clear the depth buffer and reset the scene. We wont draw anything yet.
235 */
236 bool DrawGLScene(GLvoid) // Here's where we do all the drawing
237 {
238 glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
239
240 glLoadIdentity();
241 glTranslatef(0.0f, 0.0f, -5.0f);
242 glRotatef(xrot, 1.0f, 0.0f, 0.0f);
243 glRotatef(yrot, 1.0f, 0.0f, 0.0f);
244 glRotatef(zrot, 0.0f, 0.0f, 1.0f);
245
246 glBindTexture(GL_TEXTURE_2D, texture[0]);
247 glBegin(GL_QUADS);
248 // Front face
249 glNormal3f(0.0f, 0.0f, 1.0f);
250 glTexCoord2f(1.0f, 1.0f); glVertex3f(1.0f, 1.0f, 1.0f);
251 glTexCoord2f(0.0f, 1.0f); glVertex3f(-1.0f, 1.0f, 1.0f);
252 glTexCoord2f(0.0f, 0.0f); glVertex3f(-1.0f, -1.0f, 1.0f);
253 glTexCoord2f(1.0f, 0.0f); glVertex3f(1.0f, -1.0f, 1.0f);
254 // Back face
255 glNormal3f(0.0f, 0.0f, -1.0f);
256 glTexCoord2f(1.0f, 1.0f); glVertex3f(-1.0f, 1.0f, -1.0f);
257 glTexCoord2f(0.0f, 1.0f); glVertex3f(1.0f, 1.0f, -1.0f);
258 glTexCoord2f(0.0f, 0.0f); glVertex3f(1.0f, -1.0f, -1.0f);
259 glTexCoord2f(1.0f, 0.0f); glVertex3f(-1.0f, -1.0f, -1.0f);
260 // Top face
261 glNormal3f(0.0f, 1.0f, 0.0f);
262 glTexCoord2f(1.0f, 1.0f); glVertex3f(1.0f, 1.0f, -1.0f);
263 glTexCoord2f(0.0f, 1.0f); glVertex3f(-1.0f, 1.0f, -1.0f);
264 glTexCoord2f(0.0f, 0.0f); glVertex3f(-1.0f, 1.0f, 1.0f);
265 glTexCoord2f(1.0f, 0.0f); glVertex3f(1.0f, 1.0f, 1.0f);
266 // Bottom face
267 glNormal3f(0.0f, -1.0f, 0.0f);
268 glTexCoord2f(0.0f, 0.0f); glVertex3f(1.0f, -1.0f, 1.0f);
269 glTexCoord2f(1.0f, 0.0f); glVertex3f(-1.0f, -1.0f, 1.0f);
270 glTexCoord2f(1.0f, 1.0f); glVertex3f(-1.0f, -1.0f, -1.0f);
271 glTexCoord2f(0.0f, 1.0f); glVertex3f(1.0f, -1.0f, -1.0f);
272 // Right face
273 glNormal3f(1.0f, 0.0f, 0.0f);
274 glTexCoord2f(1.0f, 0.0f); glVertex3f(1.0f, -1.0f, -1.0f);
275 glTexCoord2f(1.0f, 1.0f); glVertex3f(1.0f, 1.0f, -1.0f);
276 glTexCoord2f(0.0f, 1.0f); glVertex3f(1.0f, 1.0f, 1.0f);
277 glTexCoord2f(0.0f, 0.0f); glVertex3f(1.0f, -1.0f, 1.0f);
278 // Left face
279 glNormal3f(-1.0f, 0.0f, 0.0f);
280 glTexCoord2f(0.0f, 0.0f); glVertex3f(-1.0f, -1.0f, -1.0f);
281 glTexCoord2f(1.0f, 0.0f); glVertex3f(-1.0f, -1.0f, 1.0f);
282 glTexCoord2f(1.0f, 1.0f); glVertex3f(-1.0f, 1.0f, 1.0f);
283 glTexCoord2f(0.0f, 1.0f); glVertex3f(-1.0f, 1.0f, -1.0f);
284 glEnd();
285
286 xrot += 0.03f;
287 yrot += 0.02f;
288 zrot += 0.04f;
289 return true;
290 }
291
292 /*
293 * The job of KillGLWindow() is to release the Rendering Context,
294 * the Device Context and finally the Window Handle.
295 */
296
297 GLvoid KillGLWindow(GLvoid) // Properly kill the window
298 {
299 if (fullscreen) { // Are we in fullscreen mode
300 if (!ChangeDisplaySettings(NULL, CDS_TEST)) { // If the shortcut doesn't work
301 ChangeDisplaySettings(NULL, CDS_RESET); // Do it anyway (to get the values out of the registry)
302 ChangeDisplaySettings(&DMsaved, CDS_RESET);
303 }
304 else {
305 ChangeDisplaySettings(NULL, CDS_RESET); // If so switch back to the desktop
306 }
307 //******************************************************************************************************************************************/
308 //******************************************************************************************************************************************/
309 /*
310 * We use ChangeDisplaySettings(NULL,0) to return us to our original desktop.
311 * After we've switched back to the desktop we make the cursor visible again.
312 */
313 ShowCursor(TRUE); // Show mouse pointer
314 }
315
316 if (hRC) { // Do we have a rendering context
317 if (!wglMakeCurrent(NULL, NULL)) { // Are we able to release the DC and RC contexts
318 MessageBox(NULL, "Release of DC and RC failed.", "SHUTDOWN ERROR", MB_OK | MB_ICONINFORMATION);
319 }
320
321 if (!wglDeleteContext(hRC)) { // Are we able to delete the RC
322 MessageBox(NULL, "Release rendering context failed.", "SHUTDOWN ERROR", MB_OK | MB_ICONINFORMATION);
323 hRC = NULL; // Set RC to NULL
324 }
325
326 if (hDC && !ReleaseDC(hWnd, hDC)) { // Are we able to release the DC
327 MessageBox(NULL, "Release device context failed.", "SHUTDOWN ERROR", MB_OK | MB_ICONINFORMATION);
328 hDC = NULL; // Set DC to NULL
329 }
330 if (hWnd && !DestroyWindow(hWnd)) { // Are we able to destroy the window
331 MessageBox(NULL, "Could not release hWnd.", "SHUTDOWN ERROR", MB_OK | MB_ICONINFORMATION);
332 hWnd = NULL; // Set hWnd to NULL
333 }
334
335 if (!UnregisterClass("OpenGL", hInstance)) { // Are we able to unregister class
336 MessageBox(NULL, "Could not register class.", "SHUTDOWN ERROR", MB_OK | MB_ICONINFORMATION);
337 hInstance = NULL; // Set hInstance to NULL
338 }
339 }
340 }
341 /*
342 * The next section of code creates our OpenGL Window.
343 */
344
345 BOOL CreateGLWindow(char* title, int width, int height, int bits, bool fullscreenflag)
346 {
347 /*
348 * Find a pixel format that matches the one we want
349 */
350 GLuint PixelFormat; // Holds the result after serching for a match
351
352 /*
353 * Before you create a window, you MUST register a Class for the window
354 */
355 WNDCLASS wc; // Windows class structure
356
357 /*
358 * dwExStyle and dwStyle will store the Extended and normal Window Style Information.
359 */
360 DWORD dwExStyle; // Window extend style
361 DWORD dwStyle; // Window style
362
363
364 RECT WindowRect; // Grabs rectangle upper left/lower right values
365 WindowRect.left = (long)0; // Set left value to 0
366 WindowRect.right = (long)width; // Set right value to requested width
367 WindowRect.top = (long)0; // Set top value to 0
368 WindowRect.bottom = (long)height; // Set bottom value to requested height
369
370 fullscreen = fullscreenflag; // Set the global fullscreen flag
371
372 /*
373 * The style CS_HREDRAW and CS_VREDRAW force the Window to redraw whenever it is resized.
374 * CS_OWNDC creates a private DC for the Window. Meaning the DC is not shared across applications.
375 * WndProc is the procedure that watches for messages in our program.
376 * No extra Window data is used so we zero the two fields. Then we set the instance.
377 * Next we set hIcon to NULL meaning we don't want an ICON in the Window,
378 * and for a mouse pointer we use the standard arrow. The background color doesn't matter
379 * (we set that in GL). We don't want a menu in this Window so we set it to NULL,
380 * and the class name can be any name you want. I'll use "OpenGL" for simplicity.
381 */
382 hInstance = GetModuleHandle(NULL); // Grab an instance for our window
383 wc.style = CS_HREDRAW | CS_VREDRAW | CS_OWNDC; // Redraw on move, and own DC for window
384 wc.lpfnWndProc = (WNDPROC)WndProc; // WndProc handles message
385 wc.cbClsExtra = 0; // No extra window date
386 wc.cbWndExtra = 0; // No extra window date
387 wc.hInstance = hInstance; // set the instance
388 wc.hIcon = LoadIcon(NULL, IDI_WINLOGO); // Load the default icon
389 wc.hCursor = LoadCursor(NULL, IDC_ARROW); // Load the arrow pointer
390 wc.hbrBackground = NULL; // No background requried for GL
391 wc.lpszMenuName = NULL; // We don't want a menu
392 wc.lpszClassName = "OpenGL"; // set the class name
393
394 EnumDisplaySettings(NULL, ENUM_CURRENT_SETTINGS, &DMsaved); // Save the current display state
395
396 if (!RegisterClass(&wc)) { // Attempt to register the window class
397 MessageBox(NULL, "Failed to register the window class.", "ERROR", MB_OK | MB_ICONEXCLAMATION);
398 return FALSE; // Exit and return false
399 }
400
401 if (fullscreen) { // attempt fullsreen model
402
403 /*
404 T* here are a few very important things you should keep in mind when switching to full screen mode.
405 * Make sure the width and height that you use in fullscreen mode is the same as
406 * the width and height you plan to use for your window, and most importantly,
407 * set fullscreen mode BEFORE you create your window.
408 */
409 DEVMODE dmScreenSettings; // Device mode
410 memset(&dmScreenSettings, 0, sizeof(dmScreenSettings)); // Make sure memory's cleared
411 dmScreenSettings.dmSize = sizeof(dmScreenSettings); // Size of devmode structure
412 dmScreenSettings.dmPelsWidth = width; // Select window width
413 dmScreenSettings.dmPelsHeight = height; // Select window height
414 dmScreenSettings.dmBitsPerPel = bits; // Select bits per pixel
415 dmScreenSettings.dmFields = DM_BITSPERPEL | DM_PELSWIDTH | DM_PELSHEIGHT;
416
417 /*
418 * In the line below ChangeDisplaySettings tries to switch to a mode that matches
419 * what we stored in dmScreenSettings. I use the parameter CDS_FULLSCREEN when switching modes,
420 * because it's supposed to remove the start bar at the bottom of the screen,
421 * plus it doesn't move or resize the windows on your desktop when you switch to
422 * fullscreen mode and back.
423 */
424 //Try to set selected mode and get results. Note: CDS_FULLSCREEN gets rid of start bar
425 if (ChangeDisplaySettings(&dmScreenSettings, CDS_FULLSCREEN) != DISP_CHANGE_SUCCESSFUL) {
426 //If the mode fails, offer two options. Quit or run in a window
427 if (MessageBox(NULL, "The requested fullscreen mode is not supported by\n your video card. Use"
428 "windowed mode instead?", "GL", MB_YESNO | MB_ICONEXCLAMATION) == IDYES)
429 {
430 fullscreen = FALSE; // Select windowed mode (fullscreen=FLASE)
431 }
432 else {
433 // Pop up a message box letting user know the programe is closing.
434 MessageBox(NULL, "Program will now close.", "ERROR", MB_OK | MB_ICONSTOP);
435 return FALSE; // Exit and return FALSE
436 }
437 }
438 }
439
440 if (fullscreen) { // Are we still in fullscreen mode
441
442 /*
443 * If we are still in fullscreen mode we'll set the extended style to WS_EX_APPWINDOW,
444 * which force a top level window down to the taskbar once our window is visible.
445 * For the window style we'll create a WS_POPUP window.
446 * This type of window has no border around it, making it perfect for fullscreen mode.
447
448 * Finally, we disable the mouse pointer. If your program is not interactive,
449 * it's usually nice to disable the mouse pointer when in fullscreen mode. It's up to you though.
450 */
451 dwExStyle = WS_EX_APPWINDOW; // Window extended style
452 dwStyle = WS_POPUP; // Window style
453 ShowCursor(FALSE); // Hide mosue pointer
454 }
455 else {
456
457 /*
458 * If we're using a window instead of fullscreen mode,
459 * we'll add WS_EX_WINDOWEDGE to the extended style. This gives the window a more 3D look.
460 * For style we'll use WS_OVERLAPPEDWINDOW instead of WS_POPUP.
461 * WS_OVERLAPPEDWINDOW creates a window with a title bar, sizing border,
462 * window menu, and minimize / maximize buttons.
463 */
464 dwExStyle = WS_EX_APPWINDOW | WS_EX_WINDOWEDGE; // Window extended style
465 dwStyle = WS_OVERLAPPEDWINDOW; // Window style
466 }
467
468 /*
469 * By using the AdjustWindowRectEx command none of our OpenGL scene will be covered up by the borders,
470 * instead, the window will be made larger to account for the pixels needed to draw the window border.
471 * In fullscreen mode, this command has no effect.
472 */
473 AdjustWindowRectEx(&WindowRect, dwStyle, FALSE, dwExStyle); // Adjust window to true resqusted
474
475 /*
476 * WS_CLIPSIBLINGS and WS_CLIPCHILDREN are both REQUIRED for OpenGL to work properly.
477 * These styles prevent other windows from drawing over or into our OpenGL Window.
478 */
479 if (!(hWnd = CreateWindowEx(dwExStyle, // Extended style for the window
480 "OpenGL", // Class name
481 title, // Window title
482 WS_CLIPSIBLINGS | // Requried window style
483 WS_CLIPCHILDREN | // Requried window style
484 dwStyle, // Select window style
485 0, 0, // Window position
486 WindowRect.right - WindowRect.left, // Calculate adjusted window width
487 WindowRect.bottom - WindowRect.top, // Calculate adjusted window height
488 NULL, // No parent window
489 NULL, // No menu
490 hInstance, // Instance
491 NULL))) // Don't pass anything to WM_CREATE
492 {
493 KillGLWindow(); //Reset the display
494 MessageBox(NULL, "Window creation error.", "ERROR", MB_OK | MB_ICONEXCLAMATION);
495 return FALSE; // Retrurn FALSE;
496 }
497
498 /*
499 * aside from the stencil buffer and the (slow) accumulation buffer
500 */
501 static PIXELFORMATDESCRIPTOR pfd = // pfd tells windows how we want things to be
502 {
503 sizeof(PIXELFORMATDESCRIPTOR), // Size of this pixel format descriptor
504 1, // Version number
505 PFD_DRAW_TO_WINDOW | // Format must support window
506 PFD_SUPPORT_OPENGL | // Format must support OpenGL
507 PFD_DOUBLEBUFFER, // Must support double buffer
508 PFD_TYPE_RGBA, // Request an RGBA format
509 bits, // Select our color depth
510 0, 0, 0, 0, 0, 0, // Color bits ignored
511 0, // No alpha buffer
512 0, // shift bit ignored
513 0, // No accumulation buffer
514 0, 0, 0, 0, // Accumulation bits ignored
515 16, // 16Bits Z_Buffer (depth buffer)
516 0, // No stencil buffer
517 0, // No auxiliary buffer
518 PFD_MAIN_PLANE, // Main drawing layer
519 0, // Reserved
520 0, 0, 0 // Layer makes ignored
521 };
522
523 if (!(hDC = GetDC(hWnd))) { // Did we get a device context
524 KillGLWindow(); // Reset the display
525 MessageBox(NULL, "Can't create a GL device context.", "ERROR", MB_OK | MB_ICONEXCLAMATION);
526 return FALSE; // Return FALSE
527 }
528
529 if (!(PixelFormat = ChoosePixelFormat(hDC, &pfd))) { // Did window find a matching pixel format
530 KillGLWindow(); // Reset the display
531 MessageBox(NULL, "Can't find a suitable pixelformat.", "ERROR", MB_OK | MB_ICONEXCLAMATION);
532 return FALSE; // Return FALSE;
533 }
534
535 if (!SetPixelFormat(hDC, PixelFormat, &pfd)) { // Are we able to set the pixel format
536 KillGLWindow(); // Reset the display
537 MessageBox(NULL, "Can't set the pixelformat.", "ERROR", MB_OK | MB_ICONEXCLAMATION);
538 return FALSE; // Return FALSE;
539 }
540
541 if (!(hRC = wglCreateContext(hDC))) { // Are we able to rendering context
542 KillGLWindow(); // Reset the display
543 MessageBox(NULL, "Can't create a GL rendering context.", "ERROR", MB_OK | MB_ICONEXCLAMATION);
544 return FALSE; // Return FASLE;
545 }
546
547 if (!wglMakeCurrent(hDC, hRC)) { // Try to activate the rendering context
548 KillGLWindow(); // Reset the display
549 MessageBox(NULL, "Can't activate the GL rendering context.", "ERROR", MB_OK | MB_ICONEXCLAMATION);
550 return FALSE; // Return FALSE
551 }
552
553 /*
554 * ReSizeGLScene passing the screen width and height to set up our perspective OpenGL screen.
555 */
556 ShowWindow(hWnd, SW_SHOW); // Show the window
557 SetForegroundWindow(hWnd); // slightly higher priority
558 SetFocus(hWnd); // Sets keyboard focus to the window
559 ReSizeGLScene(width, height); // Set up our perspective GL screen
560
561 /*
562 * we can set up lighting, textures, and anything else that needs to be setup in InitGL().
563 */
564 if (!InitGL()) { // Initialize our newly created GL window
565 KillGLWindow(); // Reset the display
566 MessageBox(NULL, "Initialize Failed.", "ERROR", MB_OK | MB_ICONEXCLAMATION);
567 return FALSE; // Return FALSE
568 }
569 return TRUE;
570 }
571
572 LRESULT CALLBACK WndProc(HWND hWnd, // Handle for this window
573 UINT uMsg, // Message for this window
574 WPARAM wParam, // Additional message information
575 LPARAM lParam) // Additional message information
576 {
577 switch (uMsg) { // Check for window message
578 case WM_ACTIVATE: { // Check minimization state
579 if (!HIWORD(wParam)) {
580 active = TRUE; // Program is active
581 }
582 else {
583 active = FALSE; // Program is no longer active
584 }
585 return 0; // Return to the message loop
586 }
587 case WM_SYSCOMMAND: { // Intercept system commands
588 switch (wParam) { // Check system calls
589 case SC_SCREENSAVE: // Screensaver trying to start
590 case SC_MONITORPOWER: // Monitor trying to enter powersave
591 return 0; // Prevent form happening
592 }
593 break; // Exit
594 }
595 case WM_CLOSE: { // Did we receive a close message
596 PostQuitMessage(0); // Send a quit message
597 return 0;
598 }
599 case WM_KEYDOWN: { // Is a key being held down
600 keys[wParam] = TRUE; // if so, mark it as TRUE
601 return 0; // Jump back
602 }
603 case WM_KEYUP: { // Has a key been released
604 keys[wParam] = FALSE; // if so, mark it as FALSE
605 return 0; // Jump back
606 }
607 case WM_SIZE: { // Resize the OpenGL window
608 ReSizeGLScene(LOWORD(lParam), HIWORD(lParam)); // LoWord = width HiWord = height
609 return 0; // Jump back
610 }
611 }
612 return DefWindowProc(hWnd, uMsg, wParam, lParam); // Pass all unhandled message to DefWindwProc
613 }
614
615 int WINAPI WinMain(HINSTANCE hInstance, // Instance
616 HINSTANCE hPrevInstance, // Previous instance
617 LPSTR lpCmdLine, // Command line parameters
618 int nCmdShow) // Window show state
619 {
620 MSG msg; // Window message structure
621 BOOL done = FALSE; // Bool variable to exit loop
622 // Ask the user which screen mode they prefer
623 if (MessageBox(NULL, "Would you like to run in fullscreen mode?",
624 "Start fullscreen?", MB_YESNO | MB_ICONQUESTION) == IDNO)
625 {
626 fullscreen = FALSE; // Window mode
627 }
628 // Create our OpenGL window
629 if (!CreateGLWindow("3D Shapes", 800, 600, 32, fullscreen)) { // (Modified)
630 return 0; // Quit if window was not create
631 }
632 while (!done) { // Loop that runs until donw = TRUE
633 if (PeekMessage(&msg, NULL, 0, 0, PM_REMOVE)) { // Is there a message wating
634 if (msg.message == WM_QUIT) { // Havw we received a quit message
635 done = TRUE; // if so done = TRUE
636 }
637 else { // If not, deal with window message
638 TranslateMessage(&msg); // Translate message
639 DispatchMessage(&msg); // Dispatch message
640 }
641 }
642 else {
643 // Draw the scene. Watch for ESC key and quit message from DrawGLScene()
644 if (active) { // Program active
645 if (keys[VK_ESCAPE]) { // Was ESC pressed
646 done = TRUE; // ESC signalled a quit
647 }
648 else { // Not time to quit, update screen
649 DrawGLScene(); // Draw scene
650 SwapBuffers(hDC); // Swap buffers (double buffering)
651 //******************************************************************************************************************************************/
652 //******************************************************************************************************************************************/
653 }
654 }
655 //******************************************************************************************************************************************/
656 //******************************************************************************************************************************************/
657
658 /*
659 * It allows us to press the F1 key to switch from fullscreen mode to
660 * windowed mode or windowed mode to fullscreen mode.
661 */
662 if (keys[VK_F1]) { // Is F1 being pressed
663 keys[VK_F1] = FALSE; // If so make key FASLE
664 KillGLWindow(); // Kill our current window
665 fullscreen = !fullscreen; // Toggle fullscreen / window mode
666 //Recreate our OpenGL window(modified)
667 if (!CreateGLWindow("3D Shapes", 640, 480, 16, fullscreen)) {
668 return 0; // Quit if window was not create
669 }
670 }
671 }
672 }
673 // Shutdown
674 KillGLWindow(); // Kill the window
675 return (msg.wParam); // Exit the program
676 }blitter.cpp
Thanks for Nehe's tutorials, this is his home.
转载于:https://www.cnblogs.com/clairvoyant/p/5767508.html
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