Ive been trying the graphic programming tutorials on the site, but Im having problem with the assembly code stuff, my compiler just keeps saying its undeclared, and I know nothing about assembly so I dont know how I could fix itIs there a header I have to include?
If you are using Dev-C++ you're gonna have a hard time trying to use inline assembly. Here is a little example I found (I haven't tested it myself).
Dev-C++ uses AT&T syntax, although there is a way to make it use intel: add -masm=intel to the compiler options (I think it sometimes causes linker errors though)
When I tried to use assembly before, however, I had to use a weird syntax for declaring variables. I dug this up:
With the intel syntax option, and I think that one compiled for me. Anyways if you aren't using Dev-C++ then I just wasted my time...darn...Code:static USHORT* video_buffer __asm__("asm_buf") = (USHORT *)ddsd.lpSurface; // draw the gradient for (int index_y=0; index_y < SCREEN_HEIGHT; index_y++) { // build color word up static DWORD color __asm__("asmcolor") = _RGB16BIT565(0,(index_y >> 3),0); // replicate color in upper and lower 16 bits of 32-bit word color = (color) | (color << 16); // now color has two pixel in it in 16.16 or RGB.RGB format, use a DWORD // or 32-bit copy to move the bytes into the next video line, we'll need // inline assembly though... // draw next line, use a little inline asm baby! __asm__ ( "cld;" "les edi, [asm_buf];" "mov eax, [asmcolor];" "mov ecx, 640;" "shr ecx, 1;" "rep stosd;" ); // now advance video_buffer to next line video_buffer += (ddsd.lPitch >> 1); } // end for index_y
"Think not but that I know these things; or think
I know them not: not therefore am I short
Of knowing what I ought."
-John Milton, Paradise Regained (1671)
"Work hard and it might happen."
-XSquared
Ya, I use Dev-C++. And I dont understand the funny syntax for the AT&T one
Here Ill post what Im trying in one(decided to use dev, didnt feel like changing)
Note sure if the first line is right, but it accepts it. The second one was supposed to be the geninterrupt, but I dont know how to do it.Code:void SetMCGA() { __asm("mov %ax, 0x0013"); __asm("geninterrupt, 0x10"); //error line }
Oh and, if you dotn mind, can anyone describe the basic assembler commands for this? Im guessing(guessing... lol) that mov is kinda like a 'set' command, but I dont know what any of it does. And if you do mind it, mind saying where I can find a tutorial?
The tutorial you are looking at is rather old. The techniques offered are unlikely to work with a modern Windows compiler as they are targeted at DOS.
If you want to perform graphics in Windows you have several choices:I offer these tutorials more as a relic of programming lore than a serious study in how to program graphics in todays environment; nonetheless, if you are searching for C++ DOS graphics, these tutorials may be helpful. They are written by Grant Smith, aka Denthor of Asphyxia.
- GDI
- OpenGL
- DirectX (as used in JaWiB's post)
- SDL
- Other third party libraries
If you want to continue with the tutorial you will probably need a DOS compiler.
I would advise nehe.gamedev.net if you intend to learn opengl. Thats the best site for beginners IMO.
Regards,
Psirus
