refactor nehe08 slightly

samples/nehe08/main.c

@@ -39,6 +39,9 @@ static GLfloat yrot;        /* Y Rotation */
 static GLfloat xspeed;      /* X Rotation Speed */
 static GLfloat yspeed;      /* Y Rotation Speed */
 static GLfloat z = -5.0f;   /* Depth Into The Screen */
+GLboolean xp = GL_FALSE;
+GLboolean yp = GL_FALSE;
+GLboolean blend = GL_FALSE;
 
 static GLuint filter;       /* Which Filter To Use */
 static GLuint texture[2];   /* Storage For Two Textures */
@@ -46,7 +49,40 @@ static GLuint texture[2];   /* Storage For Two Textures */
 /* Load a PVR texture - located in pvr-texture.c */
 extern GLuint glTextureLoadPVR(char *fname, unsigned char isMipMapped, unsigned char glMipMap);
 
-void draw_gl(void) {
+/* A general OpenGL initialization function.  Sets all of the initial parameters. */
+void InitGL(int Width, int Height)	        // We call this right after our OpenGL window is created.
+{
+    glMatrixMode(GL_PROJECTION);
+    glLoadIdentity();
+    gluPerspective(45.0f, (GLfloat)Width/(GLfloat)Height, 0.1f, 100.0f);
+    glMatrixMode(GL_MODELVIEW);
+    glLoadIdentity();
+
+    glEnable(GL_TEXTURE_2D);
+    glShadeModel(GL_SMOOTH);
+    glClearColor(0.0f, 0.0f, 0.0f, 0.5f);
+    glClearDepth(1.0f);
+    glEnable(GL_DEPTH_TEST);
+    glDepthFunc(GL_LEQUAL);
+
+    glColor4f(1.0f, 1.0f, 1.0f, 0.5);
+    glBlendFunc(GL_SRC_ALPHA, GL_ONE);
+
+    /* Enable Lighting and GL_LIGHT0 */
+    glEnable(GL_LIGHTING);
+    glEnable(GL_LIGHT0);
+
+    /* Set up the textures */
+    texture[0] = glTextureLoadPVR(IMG_PATH, 0, 0);
+    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
+    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
+
+    texture[1] = glTextureLoadPVR(IMG_PATH, 0, 0);
+    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
+    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
+}
+
+void DrawGLScene(void) {
     glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
     glLoadIdentity();
     glTranslatef(0.0f, 0.0f, z);
@@ -121,122 +157,93 @@ void draw_gl(void) {
 
     xrot += xspeed;
     yrot += yspeed;
+
+    /* Finish the frame */
+    glKosSwapBuffers();
 }
 
-int main(int argc, char **argv) {
+int ReadController(void) {
 #ifdef __DREAMCAST__
     maple_device_t *cont;
     cont_state_t *state;
+
+    cont = maple_enum_type(0, MAPLE_FUNC_CONTROLLER);
+
+    /* Check key status */
+    state = (cont_state_t *)maple_dev_status(cont);
+    if(!state) {
+        printf("Error reading controller\n");
+        return 0;
+    }
+
+    if(state->buttons & CONT_START)
+        return 0;
+
+    if(state->buttons & CONT_A)
+        z -= 0.02f;
+
+    if(state->buttons & CONT_B)
+        z += 0.02f;
+
+    if((state->buttons & CONT_X) && !xp) {
+        xp = GL_TRUE;
+        filter += 1;
+
+        if(filter > 1)
+            filter = 0;
+    }
+
+    if(!(state->buttons & CONT_X))
+        xp = GL_FALSE;
+
+    if((state->buttons & CONT_Y) && !yp) {
+        yp = GL_TRUE;
+        blend = !blend;
+    }
+
+    if(!(state->buttons & CONT_Y))
+        yp = GL_FALSE;
+
+    if(state->buttons & CONT_DPAD_UP)
+        xspeed -= 0.01f;
+
+    if(state->buttons & CONT_DPAD_DOWN)
+        xspeed += 0.01f;
+
+    if(state->buttons & CONT_DPAD_LEFT)
+        yspeed -= 0.01f;
+
+    if(state->buttons & CONT_DPAD_RIGHT)
+        yspeed += 0.01f;
 #endif
 
-    GLboolean xp = GL_FALSE;
+    /* Switch to the blended polygon list if needed */
-    GLboolean yp = GL_FALSE;
+    if(blend) {
-    GLboolean blend = GL_FALSE;
+        glEnable(GL_BLEND);
+        glDepthMask(0);
+    }
+    else {
+        glDisable(GL_BLEND);
+        glDepthMask(1);
+    }
 
+    return 1;
+}
+
+int main(int argc, char **argv) {
     printf("nehe08 beginning\n");
 
     /* Get basic stuff initialized */
     glKosInit();
 
-    glMatrixMode(GL_PROJECTION);
+    InitGL(640, 480);
-    glLoadIdentity();
-    gluPerspective(45.0f, 640.0f / 480.0f, 0.1f, 100.0f);
-    glMatrixMode(GL_MODELVIEW);
-    glLoadIdentity();
-
-    glEnable(GL_TEXTURE_2D);
-    glShadeModel(GL_SMOOTH);
-    glClearColor(0.0f, 0.0f, 0.0f, 0.5f);
-    glClearDepth(1.0f);
-    glEnable(GL_DEPTH_TEST);
-    glDepthFunc(GL_LEQUAL);
-
-    glColor4f(1.0f, 1.0f, 1.0f, 0.5);
-    glBlendFunc(GL_SRC_ALPHA, GL_ONE);
-
-    /* Enable Lighting and GL_LIGHT0 */
-    glEnable(GL_LIGHTING);
-    glEnable(GL_LIGHT0);
-
-    /* Set up the textures */
-    texture[0] = glTextureLoadPVR(IMG_PATH, 0, 0);
-    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
-    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
-
-    texture[1] = glTextureLoadPVR(IMG_PATH, 0, 0);
-    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
-    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
 
     while(1) {
-#ifdef __DREAMCAST__
+        if (!ReadController())
-        cont = maple_enum_type(0, MAPLE_FUNC_CONTROLLER);
-
-        /* Check key status */
-        state = (cont_state_t *)maple_dev_status(cont);
-
-        if(!state) {
-            printf("Error reading controller\n");
-            break;
-        }
-
-        if(state->buttons & CONT_START)
             break;
 
-        if(state->buttons & CONT_A)
+        DrawGLScene();
-            z -= 0.02f;
-
-        if(state->buttons & CONT_B)
-            z += 0.02f;
-
-        if((state->buttons & CONT_X) && !xp) {
-            xp = GL_TRUE;
-            filter += 1;
-
-            if(filter > 1)
-                filter = 0;
-        }
-
-        if(!(state->buttons & CONT_X))
-            xp = GL_FALSE;
-
-        if((state->buttons & CONT_Y) && !yp) {
-            yp = GL_TRUE;
-            blend = !blend;
-        }
-
-        if(!(state->buttons & CONT_Y))
-            yp = GL_FALSE;
-
-        if(state->buttons & CONT_DPAD_UP)
-            xspeed -= 0.01f;
-
-        if(state->buttons & CONT_DPAD_DOWN)
-            xspeed += 0.01f;
-
-        if(state->buttons & CONT_DPAD_LEFT)
-            yspeed -= 0.01f;
-
-        if(state->buttons & CONT_DPAD_RIGHT)
-            yspeed += 0.01f;
-#endif
-
-        /* Switch to the blended polygon list if needed */
-        if(blend) {
-            glEnable(GL_BLEND);
-            glDepthMask(0);
-        }
-        else {
-            glDisable(GL_BLEND);
-            glDepthMask(1);
-        }
-
-        /* Draw the GL "scene" */
-        draw_gl();
-
-        /* Finish the frame */
-        glKosSwapBuffers();
     }
 
     return 0;
 }
-