/* * Graphics library * Mostly Assembly code, because efficiency in both space and time * More complex functions are written in C * Int arguments from C are stored in order of r4, r5, r6, r7 * Return value in r2, but should be written on stack using write -4 r14 r2 (add variable in C) */ // uses math.c #define GFX_WINDOW_PATTERN_ADDR 0xC01420 #define GFX_WINDOW_PALETTE_ADDR 0xC01C20 #define GFX_CURSOR_ASCII 219 word GFX_cursor = 0; // Prints to screen in window plane, with color, data is accessed in words // INPUT: // r4 = address of data to print // r5 = length of data // r6 = position on screen // r7 = palette index void GFX_printWindowColored(word addr, word len, word pos, word palette) { asm( "; backup registers\n" "push r1\n" "push r2\n" "push r3\n" "push r4\n" "push r5\n" "push r6\n" "push r7\n" "push r8\n" "push r9\n" ); asm( "; vram address\n" "load32 0xC01420 r9 ; r9 = vram addr 1056+4096 0xC01420\n" "; loop variables\n" "load 0 r1 ; r1 = loopvar\n" "or r9 r0 r3 ; r3 = vram addr with offset\n" "or r4 r0 r2 ; r2 = data addr with offset\n" "add r6 r3 r3 ; apply offset from r6\n" "; copy loop\n" "GFX_printWindowColoredLoop:\n" " read 0 r2 r8 ; read 32 bits\n" " write 0 r3 r8 ; write char to vram\n" " write 2048 r3 r7 ; write palette index to vram\n" " add r3 1 r3 ; incr vram address\n" " add r2 1 r2 ; incr data address\n" " add r1 1 r1 ; incr counter\n" " bge r1 r5 2 ; keep looping until all data is copied\n" " jump GFX_printWindowColoredLoop\n" ); asm( "; restore registers\n" "pop r9\n" "pop r8\n" "pop r7\n" "pop r6\n" "pop r5\n" "pop r4\n" "pop r3\n" "pop r2\n" "pop r1\n" ); } // Prints to screen in background plane, with color, data is accessed in words // INPUT: // r4 = address of data to print // r5 = length of data // r6 = position on screen // r7 = palette index void GFX_printBGColored(word addr, word len, word pos, word palette) { asm( "; backup registers\n" "push r1\n" "push r2\n" "push r3\n" "push r4\n" "push r5\n" "push r6\n" "push r7\n" "push r8\n" "push r9\n" ); asm( "; vram address\n" "load32 0xC00420 r9 ; r9 = vram addr 1056 0xC00420\n" "; loop variables\n" "load 0 r1 ; r1 = loopvar\n" "or r9 r0 r3 ; r3 = vram addr with offset\n" "or r4 r0 r2 ; r2 = data addr with offset\n" "add r6 r3 r3 ; apply offset from r6\n" "; copy loop\n" "GFX_printBGColoredLoop:\n" " read 0 r2 r8 ; read 32 bits\n" " write 0 r3 r8 ; write char to vram\n" " write 2048 r3 r7 ; write palette index to vram\n" " add r3 1 r3 ; incr vram address\n" " add r2 1 r2 ; incr data address\n" " add r1 1 r1 ; incr counter\n" " bge r1 r5 2 ; keep looping until all data is copied\n" " jump GFX_printBGColoredLoop\n" ); asm( "; restore registers\n" "pop r9\n" "pop r8\n" "pop r7\n" "pop r6\n" "pop r5\n" "pop r4\n" "pop r3\n" "pop r2\n" "pop r1\n" ); } // Loads entire pattern table // INPUT: // r4 = address of pattern table to copy void GFX_copyPatternTable(word addr) { asm( "; backup registers\n" "push r1\n" "push r2\n" "push r3\n" "push r4\n" "push r5\n" "push r6\n" "push r7\n" "; vram address\n" "load32 0xC00000 r2 ; r2 = vram addr 0 0xC00000\n" "; loop variables\n" "load 0 r3 ; r3 = loopvar\n" "load 1024 r5 ; r5 = loopmax\n" "or r2 r0 r1 ; r1 = vram addr with offset\n" "add r4 3 r6 ; r6 = ascii addr with offset\n" "; copy loop\n" "GFX_initPatternTableLoop:\n" " read 0 r6 r7 ; copy ascii to vram\n" " write 0 r1 r7 ;\n" " add r1 1 r1 ; incr vram address\n" " add r6 1 r6 ; incr ascii address\n" " add r3 1 r3 ; incr counter\n" " beq r3 r5 2 ; keep looping until all data is copied\n" " jump GFX_initPatternTableLoop\n" "; restore registers\n" "pop r7\n" "pop r6\n" "pop r5\n" "pop r4\n" "pop r3\n" "pop r2\n" "pop r1\n" ); } // Loads entire palette table // INPUT: // r4 = address of palette table to copy void GFX_copyPaletteTable(word addr) { asm( "; backup registers\n" "push r1\n" "push r2\n" "push r3\n" "push r4\n" "push r5\n" "push r6\n" "push r7\n" "; vram address\n" "load32 0xC00400 r2 ; r2 = vram addr 1024 0xC00400\n" "; loop variables\n" "load 0 r3 ; r3 = loopvar\n" "load 32 r5 ; r5 = loopmax\n" "or r2 r0 r1 ; r1 = vram addr with offset\n" "add r4 3 r6 ; r6 = palette addr with offset\n" "; copy loop\n" "GFX_initPaletteTableLoop:\n" " read 0 r6 r7 ; copy ascii to vram\n" " write 0 r1 r7 ;\n" " add r1 1 r1 ; incr vram address\n" " add r6 1 r6 ; incr palette address\n" " add r3 1 r3 ; incr counter\n" " beq r3 r5 2 ; keep looping until all data is copied\n" " jump GFX_initPaletteTableLoop\n" "; restore registers\n" "pop r7\n" "pop r6\n" "pop r5\n" "pop r4\n" "pop r3\n" "pop r2\n" "pop r1\n" ); } // Clear BG tile table void GFX_clearBGtileTable() { asm( "; backup registers\n" "push r1\n" "push r2\n" "push r3\n" "push r4\n" "push r5\n" "; vram address\n" "load32 0xC00420 r1 ; r1 = vram addr 1056 0xC00420\n" "; loop variables\n" "load 0 r3 ; r3 = loopvar\n" "load 2048 r4 ; r4 = loopmax\n" "or r1 r0 r5 ; r5 = vram addr with offset\n" "; copy loop\n" "GFX_clearBGtileTableLoop:\n" " write 0 r5 r0 ; clear tile\n" " add r5 1 r5 ; incr vram address\n" " add r3 1 r3 ; incr counter\n" " beq r3 r4 2 ; keep looping until all tiles are cleared\n" " jump GFX_clearBGtileTableLoop\n" "; restore registers\n" "pop r5\n" "pop r4\n" "pop r3\n" "pop r2\n" "pop r1\n" ); } // Clear BG palette table void GFX_clearBGpaletteTable() { asm( "; backup registers\n" "push r1\n" "push r2\n" "push r3\n" "push r4\n" "push r5\n" "; vram address\n" "load32 0xC00C20 r1 ; r1 = vram addr 1056+2048 0xC00C20\n" "; loop variables\n" "load 0 r3 ; r3 = loopvar\n" "load 2048 r4 ; r4 = loopmax\n" "or r1 r0 r5 ; r5 = vram addr with offset\n" "; copy loop\n" "GFX_clearBGpaletteTableLoop:\n" " write 0 r5 r0 ; clear tile\n" " add r5 1 r5 ; incr vram address\n" " add r3 1 r3 ; incr counter\n" " beq r3 r4 2 ; keep looping until all tiles are cleared\n" " jump GFX_clearBGpaletteTableLoop\n" "; restore registers\n" "pop r5\n" "pop r4\n" "pop r3\n" "pop r2\n" "pop r1\n" ); } // Clear Window tile table void GFX_clearWindowtileTable() { asm( "; backup registers\n" "push r1\n" "push r2\n" "push r3\n" "push r4\n" "push r5\n" "; vram address\n" "load32 0xC01420 r1 ; r1 = vram addr 1056+2048 0xC01420\n" "; loop variables\n" "load 0 r3 ; r3 = loopvar\n" "load 1920 r4 ; r4 = loopmax\n" "or r1 r0 r5 ; r5 = vram addr with offset\n" "; copy loop\n" "GFX_clearWindowtileTableLoop:\n" " write 0 r5 r0 ; clear tile\n" " add r5 1 r5 ; incr vram address\n" " add r3 1 r3 ; incr counter\n" " beq r3 r4 2 ; keep looping until all tiles are cleared\n" " jump GFX_clearWindowtileTableLoop\n" "; restore registers\n" "pop r5\n" "pop r4\n" "pop r3\n" "pop r2\n" "pop r1\n" ); } // Clear Window palette table void GFX_clearWindowpaletteTable() { asm( "; backup registers\n" "push r1\n" "push r2\n" "push r3\n" "push r4\n" "push r5\n" "; vram address\n" "load32 0xC01C20 r1 ; r1 = vram addr 1056+2048 0xC01C20\n" "; loop variables\n" "load 0 r3 ; r3 = loopvar\n" "load 1920 r4 ; r4 = loopmax\n" "or r1 r0 r5 ; r5 = vram addr with offset\n" "; copy loop\n" "GFX_clearWindowpaletteTableLoop:\n" " write 0 r5 r0 ; clear tile\n" " add r5 1 r5 ; incr vram address\n" " add r3 1 r3 ; incr counter\n" " beq r3 r4 2 ; keep looping until all tiles are cleared\n" " jump GFX_clearWindowpaletteTableLoop\n" "; restore registers\n" "pop r5\n" "pop r4\n" "pop r3\n" "pop r2\n" "pop r1\n" ); } // Clear Sprites void GFX_clearSprites() { asm( "; backup registers\n" "push r1\n" "push r2\n" "push r3\n" "push r4\n" "push r5\n" "; vram address\n" "load32 0xC02422 r1 ; r1 = vram addr 0xC02422\n" "; loop variables\n" "load 0 r3 ; r3 = loopvar\n" "load 64 r4 ; r4 = loopmax\n" "or r1 r0 r5 ; r5 = vram addr with offset\n" "; copy loop\n" "GFX_clearSpritesLoop:\n" " write 0 r5 r0 ; clear x\n" " write 1 r5 r0 ; clear y\n" " write 2 r5 r0 ; clear tile\n" " write 3 r5 r0 ; clear color+attrib\n" " add r5 4 r5 ; incr vram address by 4\n" " add r3 1 r3 ; incr counter\n" " beq r3 r4 2 ; keep looping until all tiles are cleared\n" " jump GFX_clearSpritesLoop\n" "; restore registers\n" "pop r5\n" "pop r4\n" "pop r3\n" "pop r2\n" "pop r1\n" ); } // Clear parameters void GFX_clearParameters() { asm( "; backup registers\n" "push r1\n" "; vram address\n" "load32 0xC02420 r1 ; r1 = vram addr 0xC02420\n" "write 0 r1 r0 ; clear tile scroll\n" "write 1 r1 r0 ; clear fine scroll\n" "; restore registers\n" "pop r1\n" ); } // Clear Pixel Engine framebuffer void GFX_clearPXframebuffer() { asm( "; backup registers\n" "push r1\n" "push r2\n" "push r3\n" "push r4\n" "push r5\n" "; vram address\n" "load32 0xD00000 r1 ; r1 = framebuffer base addr 0xD00000\n" "; loop variables\n" "load 0 r3 ; r3 = loopvar\n" "load32 76800 r4 ; r4 = loopmax\n" "or r1 r0 r5 ; r5 = fb addr with offset\n" "; copy loop\n" "GFX_clearPXframebufferLoop:\n" " write 0 r5 r0 ; clear pixel\n" " add r5 1 r5 ; incr vram address\n" " add r3 1 r3 ; incr counter\n" " beq r3 r4 2 ; keep looping until all pixels are cleared\n" " jump GFX_clearPXframebufferLoop\n" "; restore registers\n" "pop r5\n" "pop r4\n" "pop r3\n" "pop r2\n" "pop r1\n" ); } // clears and initializes VRAM (excluding pattern and palette data table) void GFX_initVram() { GFX_clearBGtileTable(); GFX_clearBGpaletteTable(); GFX_clearWindowtileTable(); GFX_clearWindowpaletteTable(); GFX_clearSprites(); GFX_clearParameters(); } // convert x and y to position for window table word GFX_WindowPosFromXY(word x, word y) { return y*40 + x; } // convert x and y to position for background table word GFX_BackgroundPosFromXY(word x, word y) { return y*64 + x; } // scrolls up screen, clearing last line void GFX_ScrollUp() { asm( "; backup registers\n" "push r1\n" "push r2\n" "push r3\n" "push r4\n" "; GFX_WINDOW_PATTERN_ADDR address\n" "load32 0xC01420 r1 ; r1 = window pattern addr 0xC01420\n" "load32 0 r2 ; r2 = loopvar\n" "load32 960 r3 ; r3 = loopmax\n" "GFX_scrollUpLoop:\n" " read 40 r1 r4 ; read r1+40 to tmp r4\n" " write 0 r1 r4 ; write tmp r4 to r1\n" " add r1 1 r1 ; incr addr r1\n" " add r2 1 r2 ; incr loopvar r2\n" " beq r2 r3 2 ; keep looping for r3 times\n" " jump GFX_scrollUpLoop\n" "load32 0 r2 ; r2 = loopvar\n" "load32 40 r3 ; r3 = loopmax\n" "GFX_clearLastLineLoop:\n" " write 0 r1 r0 ; clear at r1\n" " add r1 1 r1 ; incr addr r1\n" " add r2 1 r2 ; incr loopvar r2\n" " beq r2 r3 2 ; keep looping for r3 times\n" " jump GFX_clearLastLineLoop\n" "; restore registers\n" "pop r4\n" "pop r3\n" "pop r2\n" "pop r1\n" ); } // Prints cursor character at cursor void GFX_printCursor() { // print character at cursor word *v = (word *) GFX_WINDOW_PATTERN_ADDR; *(v+GFX_cursor) = GFX_CURSOR_ASCII; } // Prints character to console // Handles scrolling, newline and backspace // Uses cursor from memory // TODO: could convert this to assembly for speed void GFX_PrintcConsole(char c) { // if newline if (c == 0xa) { // remove current cursor word *v = (word *) GFX_WINDOW_PATTERN_ADDR; *(v+GFX_cursor) = 0; // get next line number word nl = MATH_divU(GFX_cursor, 40) + 1; // multiply by 40 to get the correct line GFX_cursor = nl * 40; } // if backspace else if (c == 0x8) { // NOTE: by commenting this out it now is allowed to backspace to the previous line // This is done since the shell checks for valid backspaces now, // so we can remove multiline arguments // if we are not at the start of a line //if (MATH_mod(GFX_cursor, 40) != 0) // if we are not at the first character if ((unsigned int) GFX_cursor > 0) { // set current and previous character to 0 word *v = (word *) GFX_WINDOW_PATTERN_ADDR; *(v+GFX_cursor) = 0; *(v+GFX_cursor-1) = 0; // decrement cursor GFX_cursor -= 1; } } // if\r else if (c == '\r') { // ignore } // else (character) else { // print character at cursor word *v = (word *) GFX_WINDOW_PATTERN_ADDR; *(v+GFX_cursor) = (word) c; // increment cursor GFX_cursor += 1; } // if we went offscreen, scroll screen up and set cursor to last line if ((unsigned int) GFX_cursor >= 1000) { GFX_ScrollUp(); // set cursor to 960 GFX_cursor = 960; } // add cursor at end GFX_printCursor(); } // Prints string on console untill terminator // Does not add newline at end // TODO: could convert this to assembly for speed void GFX_PrintConsole(char* str) { char chr = *str; // first character of str while (chr != 0) // continue until null value { GFX_PrintcConsole((word)chr); str++; // go to next character address chr = *str; // get character from address } } // Clears console by removing all tiles and resetting the cursor void GFX_clearConsole() { GFX_clearWindowtileTable(); GFX_clearBGtileTable(); GFX_cursor = 0; }