fenbf / soil_ext

Updates to the SOIL image lib: mipmaps, core opengl

#Simple OpenGL Image Library Ext# The original SOIL from July 7, 2008 is released with Public Domain Licence.

The Ext version contains the following changes:

• [in progress] Added option to use immutable texture storage
• When possible (when extension is supported) library can create texture using glTextureStorage and then call glTexSubImage.
• See more here OpenGL wiki
• [done] Mipmap generation using glGenerateMipmap
• Original library scaled image to be POT and then used custom procedure to generate mipmaps. This can take some time.
• This change uses glGenerateMipmapEXT (if GL_EXT_framebuffer_object extension is available). This way Soil can create mipmaps for NPOT textures and use hardware support.
• New flag is added: SOIL_FLAG_GL_MIPMAPS. It can be passed to the SOIL_load_OGL_texture* procedures. If the extension (GL_EXT_framebuffer_object) is not supported then function uses the same process as when passing SOIL_FLAG_MIPMAPS.
• [done] upgraded to the version 1.33 of stb_image
• stb_image_write.c/.h were created. Those files contain missing functionality that was cut from the newer version of stbi (cut in 1.22)
• [done] Using only Modern OpenGL functionalities (when possible)
• CLAMP_TO_EDGE instead of GL_CLAMP
• glGetStringi instead of glGetString(GL_EXTENSIONS)
• [done] Visual Studio 2012 Express solution
• It compiles without any warnings: used _CRT_SECURE_NO_WARNINGS and several code changes regarding int/float cast and signed/unsigned comparisons.
• Added test_soil project to the solution. Console is showed to display basic loader info.
• Building with Debug Information Format set to "" (Empty). That way output file is smaller and there are no warnings about missing pdb files.
• [done] Added test_perf_SOIL test project
• Tests performance of SOIL_FLAG_GL_MIPMAPS vs SOIL_FLAG_MIPMAPS
• Loads 10... or 100 textures and measures elapsed time.

###Notes###

• Original functionality is preserved and should work as expected.
• Doc comments were updated to describe changes
• Needs more testing :)