So the problem: I draw two or three textures on screen at the end of every custom display loop, based on PNGs with transparent backgrounds, using lodePNG to do so (a quick file set that works really well for just getting PNGs in, and that's it. No fancy loading bits), only sometimes the PNG textures show up as light yellow or pure white boxes of the same size (probably pure white, just hard for me to tell and screenshots aren't working) and other times they completely refuse to show up. Strangest yet is it differs from texture to texture, and sometimes one shows up fine and the other never appears, or they'll show up but freeze, or freeze and some combination of appearing well, appearing as white boxes, or not showing up.
I think it has to do with glEnable(GL_TEXTURE_2D) since moving that around influences other elements. I used to have a problem where the screen would flash a silhouette of the 3D models when leaving PNG mode (the pause screen) but got rid of that by putting glDisable(GL_TEXTURE_2D) at the beginning of every new draw call, and not putting it at the end even though usually it's main draw calls, glEnable(GL_TEXTURE_2D), pause menu draw calls/PNG usage, glDisable(GL_TEXTURE_2D).
Anyways, I'm probably butchering all that. Here's some code to clear things up:
void display() { glScissor(0,0,windowWidth,windowHeight); glViewport(0,0,windowWidth,windowHeight); // Make sure background is black first, then draw on top of it glClearColor(0.0f, 0.0f, 0.0f, 0.0f); glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT); // do not understand order, but this works // Drawing all player views for (int i=0; i<getPlayerCount(); i++) { if (getPlayerPlayable(i)) { // First take care of remnants from last menu glDisable(GL_TEXTURE_2D); // Four player splitscreen vals int posX = windowWidth/2*(i==1 || i==3); int posY = windowHeight/2*(i==2 || i==3); int viewW = windowWidth*1/2; int viewH = windowHeight*1/2; glScissor(posX,posY,viewW,viewH); glViewport(posX, posY, viewW, viewH); // custom draw commands for view of 3D world displayFor(i); // Menu drawing glEnable(GL_TEXTURE_2D); drawMenu(i); } } glutSwapBuffers(); }
And since it's referenced, may as well throw in displayFor too:
// Draw an entire player's screen void displayFor(int player) { // Paint background cyan to neon blue glClearColor(getMapRed(), getMapGreen(), getMapBlue(), 0.0f); // do this here to allow black borders glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT); glMatrixMode(GL_MODELVIEW); // must set this here to undo silhouette's effects later glLoadIdentity(); /* Push Matrix, scale, rotate, translate, and draw vertices go in here with different calls, then a pop matrix to end it */ /* There's also a shadow function in there with some stuff I'm not fully comfortable with yet, will post that if needed */ }
So finally, the drawMenu function
// Draws the 2D PNGs themselves as textures void drawMenu(int i) { // Don't use whole viewport since different menu for every player //glViewport(0, 0, windowWidth, windowHeight); // don't need? glMatrixMode(GL_PROJECTION); // necessary glLoadIdentity(); // this one seems to be necessary // Actual dimensions compared to expected dimensions (for now, my screen fullscreen) GLfloat aspect = ((GLfloat)windowWidth / (GLfloat)windowHeight)/(1600.0/1050.0); //gluPerspective(45.0, aspect*windowWidth/windowHeight, 0.050, 100.0); if (aspect > 1.0) { glOrtho(0, 1600*aspect, 1050, 0, -1, 1); // necessary } else { glOrtho(0, 1600, 1050/aspect, 0, -1, 1); // necessary } //glOrtho(0, 1600*aspect, 1050, 0, -1, 1); // necessary glMatrixMode(GL_MODELVIEW); // don't need? glLoadIdentity(); // don't need? glDisable(GL_CULL_FACE); //glDisable(GL_DEPTH_TEST); glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA); glEnable(GL_BLEND); glDisable(GL_ALPHA_TEST); // no visible effect yet // Enable the texture for OpenGL. glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR); // slight smoothing when smaller than norm glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST); // no smoothing when full size and up // Still unsure of functionality, but known importance! // glColor4ub brings back color to the PNG where it was black before glColor4ub(255, 255, 255, 255); // Where the logo is for bouncing/rotating int time; time = clock(); // Only draw any of it if paused if (!getGameplayRunning()) { // Start screen? if (getLastPause() == -1) { logoImage.draw(20.0*sin(time/1600.0),50+10.0*sin(time/800.0),aspect,false); // Blink the press start/enter image if (time%1200 < 900) { if (joystickConnected()) { pressStartImage.draw(0,700,aspect,false); } else { pressEnterImage.draw(0,700,aspect,false); } } // Regular pause! } else { int option = getOption(i); // Option currently selected float rotation = 5.0*sin(time/300.0); // Selected option rotates back and forth resumeImage.draw(0,25,aspect,(option==0)*rotation); creditsImage.draw(0,325,aspect,(option==1)*rotation); // will be options later quitImage.draw(0,625,aspect,(option==2)*rotation); } } glDisable(GL_BLEND); glEnable(GL_ALPHA_TEST); // depth test removed, was enabled here and disabled above, caused flashing //glEnable(GL_DEPTH_TEST); glEnable(GL_CULL_FACE); }
Er, and I guess you want to see how my Image class works too. This is it, I promise!
#include "image.h" #ifdef __APPLE_CC__ #include <GLUT/glut.h> #else #include <GL/glut.h> #endif #include "lodepng.h" // for 2D images, all PNG based for transparency // lodePNG copyright (c) 2005-2012 Lode Vandevenne #include <iostream> // for couts using namespace std; // No file name? Hardly an image now is it. Image::Image() { u2 = 0; u3 = 0; v2 = 0; v3 = 0; } // Constructor! Take a file name in Image::Image(const char* name) { unsigned error1 = lodepng::decode(texture, width, height, name); // Texture size must be power of two for the primitive OpenGL version this is written for. Find next power of two. u2 = 1; while(u2 < width) u2 *= 2; v2 = 1; while(v2 < height) v2 *= 2; // Ratio for power of two version compared to actual version, to render the non power of two image with proper size. u3 = (double)width / u2; v3 = (double)height / v2; } // Draw self at a location void Image::draw(int x, int y, float aspect, float rotate) { // Would like to move this out of draw if possible // Make power of two version of the image. std::vector<unsigned char> image2(u2 * v2 * 4); for(size_t y = 0; y < height; y++) for(size_t x = 0; x < width; x++) for(size_t c = 0; c < 4; c++) { image2[4 * u2 * y + 4 * x + c] = texture[4 * width * y + 4 * x + c]; } glTexImage2D(GL_TEXTURE_2D, 0, 4, u2, v2, 0, GL_RGBA, GL_UNSIGNED_BYTE, &image2[0]); float currentTextureX = x; float currentTextureY = y; //glTranslatef(0.0,0.0,10.0); glPushMatrix(); // Always keep in center of screen, regardless of size/resolution // And use aspect from earlier to do this, and 1600 as expected/base width if (aspect > 1.0) { glTranslatef(1600*aspect/2+currentTextureX, 0.0f+height/2+currentTextureY,0.0f); } else { glTranslatef(1600/2+currentTextureX, 0.0f+height/2+currentTextureY,0.0f); } glPushMatrix(); glRotatef(rotate,0.0,0.0,1.0); // Draw the texture on a quad, using u3 and v3 to correct non power of two texture size. glBegin(GL_QUADS); glTexCoord2d( 0, 0); glVertex2f(0-width/2.0, 0-height/2.0); glTexCoord2d(u3, 0); glVertex2f(0+width/2.0, 0-height/2.0); glTexCoord2d(u3, v3); glVertex2f(0+width/2.0, 0+height/2.0); glTexCoord2d( 0, v3); glVertex2f(0-width/2.0, 0+height/2.0); glEnd(); glPopMatrix(); glPopMatrix(); }
Thanks guys! I know this is a lot of code to provide... but I'm really not sure how to cut it down more than that at this point.