--- /dev/null
+#include "image_loader.h"
+#include <cmath>
+
+#include "wx/image.h"
+#include "wx/wx.h"
+
+
+GLuint* loadImage(wxString path, int* imageWidth, int* imageHeight, int* textureWidth, int* textureHeight)
+{
+
+ GLuint* ID=new GLuint[1];
+ glGenTextures( 1, &ID[0] );
+
+ glBindTexture( GL_TEXTURE_2D, *ID );
+
+ // the first time, init image handlers (remove this part if you do it somewhere else in your app)
+ static bool is_first_time = true;
+ if(is_first_time)
+ {
+ wxInitAllImageHandlers();
+
+ is_first_time = false;
+ }
+
+ // check the file exists
+ if(!wxFileExists(path))
+ {
+ wxMessageBox( _("Failed to load resource image") );
+ exit(1);
+ }
+
+ wxImage* img=new wxImage( path );
+
+ (*imageWidth)=img->GetWidth();
+ (*imageHeight)=img->GetHeight();
+
+ glPixelStorei(GL_UNPACK_ALIGNMENT, 1 );
+
+ /*
+ * Many graphics card require that textures be power of two.
+ * Below is a simple implementation, probably not optimal but working.
+ * If your texture sizes are not restricted to power of 2s, you can
+ * of course adapt the bit below as needed.
+ */
+
+ float power_of_two_that_gives_correct_width=std::log((float)(*imageWidth))/std::log(2.0);
+ float power_of_two_that_gives_correct_height=std::log((float)(*imageHeight))/std::log(2.0);
+
+ // check if image dimensions are a power of two
+ if( (int)power_of_two_that_gives_correct_width == power_of_two_that_gives_correct_width &&
+ (int)power_of_two_that_gives_correct_height == power_of_two_that_gives_correct_height)
+ {
+ // note: must make a local copy before passing the data to OpenGL, as GetData() returns RGB
+ // and we want the Alpha channel if it's present. Additionally OpenGL seems to interpret the
+ // data upside-down so we need to compensate for that.
+ GLubyte *bitmapData=img->GetData();
+ GLubyte *alphaData=img->GetAlpha();
+
+ int bytesPerPixel = img->HasAlpha() ? 4 : 3;
+
+ int imageSize = (*imageWidth) * (*imageHeight) * bytesPerPixel;
+ GLubyte *imageData=new GLubyte[imageSize];
+
+ int rev_val=(*imageHeight)-1;
+
+ for(int y=0; y<(*imageHeight); y++)
+ {
+ for(int x=0; x<(*imageWidth); x++)
+ {
+ imageData[(x+y*(*imageWidth))*bytesPerPixel+0]=
+ bitmapData[( x+(rev_val-y)*(*imageWidth))*3];
+
+ imageData[(x+y*(*imageWidth))*bytesPerPixel+1]=
+ bitmapData[( x+(rev_val-y)*(*imageWidth))*3 + 1];
+
+ imageData[(x+y*(*imageWidth))*bytesPerPixel+2]=
+ bitmapData[( x+(rev_val-y)*(*imageWidth))*3 + 2];
+
+ if(bytesPerPixel==4) imageData[(x+y*(*imageWidth))*bytesPerPixel+3]=
+ alphaData[ x+(rev_val-y)*(*imageWidth) ];
+ }//next
+ }//next
+
+ // if yes, everything is fine
+ glTexImage2D(GL_TEXTURE_2D,
+ 0,
+ bytesPerPixel,
+ *imageWidth,
+ *imageHeight,
+ 0,
+ img->HasAlpha() ? GL_RGBA : GL_RGB,
+ GL_UNSIGNED_BYTE,
+ imageData);
+
+ (*textureWidth) = (*imageWidth);
+ (*textureHeight) = (*imageHeight);
+
+ delete [] imageData;
+ }
+ else // texture is not a power of two. We need to resize it
+ {
+
+ int newWidth=(int)std::pow( 2.0, (int)(std::ceil(power_of_two_that_gives_correct_width)) );
+ int newHeight=(int)std::pow( 2.0, (int)(std::ceil(power_of_two_that_gives_correct_height)) );
+
+ //printf("Unsupported image size. Recommand values: %i %i\n",newWidth,newHeight);
+
+ GLubyte *bitmapData=img->GetData();
+ GLubyte *alphaData=img->GetAlpha();
+
+ int old_bytesPerPixel = 3;
+ int bytesPerPixel = img->HasAlpha() ? 4 : 3;
+
+ int imageSize = newWidth * newHeight * bytesPerPixel;
+ GLubyte *imageData=new GLubyte[imageSize];
+
+ int rev_val=(*imageHeight)-1;
+
+ for(int y=0; y<newHeight; y++)
+ {
+ for(int x=0; x<newWidth; x++)
+ {
+
+ if( x<(*imageWidth) && y<(*imageHeight) ){
+ imageData[(x+y*newWidth)*bytesPerPixel+0]=
+ bitmapData[( x+(rev_val-y)*(*imageWidth))*old_bytesPerPixel + 0];
+
+ imageData[(x+y*newWidth)*bytesPerPixel+1]=
+ bitmapData[( x+(rev_val-y)*(*imageWidth))*old_bytesPerPixel + 1];
+
+ imageData[(x+y*newWidth)*bytesPerPixel+2]=
+ bitmapData[( x+(rev_val-y)*(*imageWidth))*old_bytesPerPixel + 2];
+
+ if(bytesPerPixel==4) imageData[(x+y*newWidth)*bytesPerPixel+3]=
+ alphaData[ x+(rev_val-y)*(*imageWidth) ];
+
+ }
+ else
+ {
+
+ imageData[(x+y*newWidth)*bytesPerPixel+0] = 0;
+ imageData[(x+y*newWidth)*bytesPerPixel+1] = 0;
+ imageData[(x+y*newWidth)*bytesPerPixel+2] = 0;
+ if(bytesPerPixel==4) imageData[(x+y*newWidth)*bytesPerPixel+3] = 0;
+ }
+
+ }//next
+ }//next
+
+
+ glTexImage2D(GL_TEXTURE_2D,
+ 0,
+ img->HasAlpha() ? 4 : 3,
+ newWidth,
+ newHeight,
+ 0,
+ img->HasAlpha() ? GL_RGBA : GL_RGB,
+ GL_UNSIGNED_BYTE,
+ imageData);
+
+ (*textureWidth)=newWidth;
+ (*textureHeight)=newHeight;
+
+ delete [] imageData;
+ }
+
+ // set texture parameters as you wish
+ glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST); // GL_LINEAR
+ glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST); // GL_LINEAR
+
+ glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
+ glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
+
+ return ID;
+
+}
projects / dcpomatic.git / blobdiff