diff options
Diffstat (limited to 'main.cpp')
| -rw-r--r-- | main.cpp | 68 |
1 files changed, 61 insertions, 7 deletions
@@ -490,11 +490,42 @@ void mainLoop(void){ void render(){ /* - * TODO fix this dense garbage ANDY :D lol hahahaha XDSSDSDDDDD + * These functions run everyloop to update the current stacks presets + * + * Matrix ---- A matrix is a blank "canvas" for the renderer to draw on, + * this canvas can be rotated, scales, skewed, etc.. + * + * Stack ---- A stack is exactly what it sounds like, it is a stack.. A + * stack is a "stack" of matrices for the renderer to draw on. + * Each stack can be made up of varying amounts of matricies. + * + * glMatrixMode This changes our current stacks mode so the drawings below + * it can take on certain traits. + * + * GL_PROJECTION This is the matrix mode that sets the cameras position, + * GL_PROJECTION is made up of a stack with two matrices which + * means we can make up to 2 seperate changes to the camera. + * + * GL_MODELVIEW This matrix mode is set to have the dimensions defined above + * by GL_PROJECTION so the renderer can draw only what the camera + * is looking at. GL_MODELVIEW has a total of 32 matrices on it's + * stack, so this way we can make up to 32 matrix changes like, + * scaling, rotating, translating, or flipping. + * + * glOrtho glOrtho sets our ortho, or our cameras resolution. This can also + * be used to set the position of the camera on the x and y axis + * like we have done. The glOrtho must be set while the stack is in + * GL_PROJECTION mode, as this is the mode that gives the + * camera properties. + * + * glPushMatrix This creates a "new" matrix. What it really does is pull a matrix + * off the bottom of the stack and puts it on the top so the renderer + * can draw on it. + * + * glLoadIdentity This scales the current matrix back to the origin so the + * translations are seen normally on a stack. */ - //a matrix is a blank canvas for the computer to draw on, the matrices are stored in a "stack" - //GL_PROJECTION has 2 matrices - //GL_MODELVIEW has 32 matrices + glMatrixMode(GL_PROJECTION); //set the matrix mode as projection so we can set the ortho size and the camera settings later on glPushMatrix(); //push the matrix to the top of the matrix stack glLoadIdentity(); //replace the entire matrix stack with the updated GL_PROJECTION mode @@ -503,8 +534,20 @@ void render(){ glPushMatrix(); //push the matrix to the top of the matrix stack glLoadIdentity(); //replace the entire matrix stack with the updated GL_MODELVIEW mode glPushMatrix(); //basically here we put a blank canvas (new matrix) on the screen to draw on + + /* + * glPushAttrib This passes attributes to the renderer so it knows what it can + * render. In our case, GL_DEPTH_BUFFER_BIT allows the renderer to + * draw multiple objects on top of one another without blending the + * objects together; GL_LIGHING_BIT allows the renderer to use shaders + * and other lighting effects to affect the scene. + * + * glClear This clears the new matrices using the type passed. In our case: + * GL_COLOR_BUFFER_BIT allows the matrices to have color on them + */ + glPushAttrib( GL_DEPTH_BUFFER_BIT | GL_LIGHTING_BIT ); - glClear(GL_COLOR_BUFFER_BIT); //clear the matrix on the top of the stack + glClear(GL_COLOR_BUFFER_BIT); /************************** **** RENDER STUFF HERE **** @@ -582,8 +625,19 @@ void render(){ **** END RENDERING **** **************************/ - glPopMatrix(); //take the matrix(s) off the stack to pass them to the renderer - SDL_GL_SwapWindow(window); //give the stack to SDL to render it + /* + * These next two function finish the rendering\ + * + * glPopMatrix This anchors all of the matrices and blends them to a single + * matrix so the renderer can draw this to the screen, since screens + * are only 2 dimensions, we have to combine the matrixes to be 2d. + * + * SDL_GL_SwapWindow Since SDL has control over our renderer, we need to now give our + * new matrix to SDL so it can pass it to the window. + */ + + glPopMatrix(); + SDL_GL_SwapWindow(window); } void logic(){ |