+#include <png.h>
+#include <msp/error.h>
+#include "texture2d.h"
+
+using namespace std;
+
+namespace Msp {
+namespace GL {
+
+Texture2D::Texture2D()
+{
+ target=GL_TEXTURE_2D;
+}
+
+/**
+Uploads an image into the texture. Direct wrapper for glTexImage2D.
+*/
+void Texture2D::image(int level, int ifmt, sizei width, sizei height, int border, GLenum fmt, GLenum type, void *data)
+{
+ if(bound!=this) bind();
+ glTexImage2D(target, level, ifmt, width, height, border, fmt, type, data);
+}
+
+/**
+Uploads an image into the texture.
+*/
+void Texture2D::image(int level, sizei width, sizei height, TextureFormat tfmt, void *data)
+{
+ int ifmt;
+ int fmt;
+ int type;
+
+ switch(tfmt)
+ {
+ case LUMINANCE8: ifmt=GL_LUMINANCE; fmt=GL_LUMINANCE; type=GL_UNSIGNED_BYTE; break;
+ case LUMINANCE8_ALPHA8: ifmt=GL_LUMINANCE_ALPHA; fmt=GL_LUMINANCE_ALPHA; type=GL_UNSIGNED_BYTE; break;
+ case RGB8: ifmt=GL_RGB; fmt=GL_RGB; type=GL_UNSIGNED_BYTE; break;
+ case RGBA8: ifmt=GL_RGBA; fmt=GL_RGBA; type=GL_UNSIGNED_INT_8_8_8_8; break;
+ case BGR8: ifmt=GL_RGB; fmt=GL_BGR; type=GL_UNSIGNED_BYTE; break;
+ case BGRA8: ifmt=GL_RGBA; fmt=GL_BGRA; type=GL_UNSIGNED_INT_8_8_8_8; break;
+ default: return;
+ }
+
+ image(level, ifmt, width, height, 0, fmt, type, data);
+}
+
+/**
+Loads an image from a file and uploads it into the texture. Currently assumes
+the file to be a PNG image.
+*/
+void Texture2D::image(const string &fn)
+{
+ FILE *file=fopen(fn.c_str(), "r");
+ if(!file) throw Exception("Couldn't open "+fn);
+
+ char sig[8];
+ fread(sig, 8, 1, file);
+ if(png_sig_cmp((png_byte *)sig, 0, 8))
+ throw Exception("Not a PNG image");
+
+ png_struct *pngs=png_create_read_struct(PNG_LIBPNG_VER_STRING, 0, 0, 0);
+ png_info *pngi=png_create_info_struct(pngs);
+
+ if(setjmp(png_jmpbuf(pngs)))
+ {
+ png_destroy_read_struct(&pngs, &pngi, 0);
+ fclose(file);
+ throw Exception("PNG error");
+ }
+ png_init_io(pngs, file);
+ png_set_sig_bytes(pngs, 8);
+
+ png_read_info(pngs, pngi);
+
+ unsigned width=png_get_image_width(pngs, pngi);
+ unsigned height=png_get_image_height(pngs, pngi);
+ unsigned depth=png_get_bit_depth(pngs, pngi);
+ unsigned ctype=png_get_color_type(pngs, pngi);
+
+ if(ctype==PNG_COLOR_TYPE_PALETTE || depth<8)
+ {
+ png_destroy_read_struct(&pngs, &pngi, 0);
+ fclose(file);
+ throw Exception("Invalid color type or bit depth");
+ }
+
+ if(depth==16)
+ png_set_strip_16(pngs);
+
+ TextureFormat fmt;
+ unsigned planes;
+
+ switch(ctype)
+ {
+ case PNG_COLOR_TYPE_GRAY: fmt=LUMINANCE8; planes=1; break;
+ case PNG_COLOR_TYPE_GRAY_ALPHA: fmt=LUMINANCE8_ALPHA8; planes=2; break;
+ case PNG_COLOR_TYPE_RGB: fmt=RGB8; planes=3; break;
+ case PNG_COLOR_TYPE_RGB_ALPHA: fmt=RGBA8; planes=4; break;
+ }
+
+ png_byte *data=(png_byte *)malloc(width*height*planes);
+ png_byte *row_ptrs[height];
+ for(unsigned i=0; i<height; ++i)
+ row_ptrs[i]=data+(height-1-i)*width*planes;
+
+ png_read_image(pngs, row_ptrs);
+
+ image(0, width, height, fmt, data);
+ free(data);
+
+ png_destroy_read_struct(&pngs, &pngi, 0);
+ fclose(file);
+}
+
+} // namespace GL
+} // namespace Msp