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Diffstat (limited to 'src/VBox/Additions/x11/VBoxClient/display-svga-xf86cvt.cpp')
| -rw-r--r-- | src/VBox/Additions/x11/VBoxClient/display-svga-xf86cvt.cpp | 310 |
1 files changed, 310 insertions, 0 deletions
diff --git a/src/VBox/Additions/x11/VBoxClient/display-svga-xf86cvt.cpp b/src/VBox/Additions/x11/VBoxClient/display-svga-xf86cvt.cpp new file mode 100644 index 00000000..5263ffbf --- /dev/null +++ b/src/VBox/Additions/x11/VBoxClient/display-svga-xf86cvt.cpp @@ -0,0 +1,310 @@ +/* $Id: display-svga-xf86cvt.cpp $ */ +/** @file + * Guest Additions - Our version of xf86CVTMode. + */ + +/* + * Copyright (C) 2006-2023 Oracle and/or its affiliates. + * This file is based on x.org server 1.18.0 file xf86cvt.c: + * + * Copyright 2005-2006 Luc Verhaegen. + * + * Permission is hereby granted, free of charge, to any person obtaining a + * copy of this software and associated documentation files (the "Software"), + * to deal in the Software without restriction, including without limitation + * the rights to use, copy, modify, merge, publish, distribute, sublicense, + * and/or sell copies of the Software, and to permit persons to whom the + * Software is furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice shall be included in + * all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL + * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR + * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, + * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR + * OTHER DEALINGS IN THE SOFTWARE. + */ + +#if 0 +/* + * The reason for having this function in a file of its own is + * so that ../utils/cvt/cvt can link to it, and that xf86CVTMode + * code is shared directly. + */ + +#ifdef HAVE_XORG_CONFIG_H +#include <xorg-config.h> +#else +#ifdef HAVE_CONFIG_H +#include <config.h> +#endif +#endif + +#include "xf86.h" +#include "xf86Modes.h" + +#include <string.h> +#else +# include "VBoxClient.h" +# include "display-svga-xf86cvt.h" +#endif + +/* + * This is a slightly modified version of the xf86CVTMode function from + * xf86cvt.c from the xorg xserver source code. Computes several parameters + * of a display mode out of horizontal and vertical resolutions. Replicated + * here to avoid further dependencies. + * + *---------------------------------------------------------------------------- + * + * Generate a CVT standard mode from HDisplay, VDisplay and VRefresh. + * + * These calculations are stolen from the CVT calculation spreadsheet written + * by Graham Loveridge. He seems to be claiming no copyright and there seems to + * be no license attached to this. He apparently just wants to see his name + * mentioned. + * + * This file can be found at http://www.vesa.org/Public/CVT/CVTd6r1.xls + * + * Comments and structure corresponds to the comments and structure of the xls. + * This should ease importing of future changes to the standard (not very + * likely though). + * + * About margins; i'm sure that they are to be the bit between HDisplay and + * HBlankStart, HBlankEnd and HTotal, VDisplay and VBlankStart, VBlankEnd and + * VTotal, where the overscan colour is shown. FB seems to call _all_ blanking + * outside sync "margin" for some reason. Since we prefer seeing proper + * blanking instead of the overscan colour, and since the Crtc* values will + * probably get altered after us, we will disable margins altogether. With + * these calculations, Margins will plainly expand H/VDisplay, and we don't + * want that. -- libv + * + */ +DisplayModeR VBoxClient_xf86CVTMode(int HDisplay, int VDisplay, float VRefresh /* Herz */, bool Reduced, bool Interlaced) +{ + DisplayModeR Mode; + + /* 1) top/bottom margin size (% of height) - default: 1.8 */ +#define CVT_MARGIN_PERCENTAGE 1.8 + + /* 2) character cell horizontal granularity (pixels) - default 8 */ +#define CVT_H_GRANULARITY 8 + + /* 4) Minimum vertical porch (lines) - default 3 */ +#define CVT_MIN_V_PORCH 3 + + /* 4) Minimum number of vertical back porch lines - default 6 */ +#define CVT_MIN_V_BPORCH 6 + + /* Pixel Clock step (kHz) */ +#define CVT_CLOCK_STEP 250 + + bool Margins = false; + float VFieldRate, HPeriod; + int HDisplayRnd, HMargin; + int VDisplayRnd, VMargin, VSync; + float Interlace; /* Please rename this */ + + /* CVT default is 60.0Hz */ + if (!VRefresh) + VRefresh = 60.0; + + /* 1. Required field rate */ + if (Interlaced) + VFieldRate = VRefresh * 2; + else + VFieldRate = VRefresh; + + /* 2. Horizontal pixels */ + HDisplayRnd = HDisplay - (HDisplay % CVT_H_GRANULARITY); + + /* 3. Determine left and right borders */ + if (Margins) { + /* right margin is actually exactly the same as left */ + HMargin = (int)((float)HDisplayRnd * CVT_MARGIN_PERCENTAGE / 100.0); + HMargin -= HMargin % CVT_H_GRANULARITY; + } + else + HMargin = 0; + + /* 4. Find total active pixels */ + Mode.HDisplay = HDisplayRnd + 2 * HMargin; + + /* 5. Find number of lines per field */ + if (Interlaced) + VDisplayRnd = VDisplay / 2; + else + VDisplayRnd = VDisplay; + + /* 6. Find top and bottom margins */ + /* nope. */ + if (Margins) + /* top and bottom margins are equal again. */ + VMargin = (int)((float)VDisplayRnd * CVT_MARGIN_PERCENTAGE / 100.0); + else + VMargin = 0; + + Mode.VDisplay = VDisplay + 2 * VMargin; + + /* 7. Interlace */ + if (Interlaced) + Interlace = 0.5; + else + Interlace = 0.0; + + /* Determine VSync Width from aspect ratio */ + if (!(VDisplay % 3) && ((VDisplay * 4 / 3) == HDisplay)) + VSync = 4; + else if (!(VDisplay % 9) && ((VDisplay * 16 / 9) == HDisplay)) + VSync = 5; + else if (!(VDisplay % 10) && ((VDisplay * 16 / 10) == HDisplay)) + VSync = 6; + else if (!(VDisplay % 4) && ((VDisplay * 5 / 4) == HDisplay)) + VSync = 7; + else if (!(VDisplay % 9) && ((VDisplay * 15 / 9) == HDisplay)) + VSync = 7; + else /* Custom */ + VSync = 10; + + if (!Reduced) { /* simplified GTF calculation */ + + /* 4) Minimum time of vertical sync + back porch interval (µs) + * default 550.0 */ +#define CVT_MIN_VSYNC_BP 550.0 + + /* 3) Nominal HSync width (% of line period) - default 8 */ +#define CVT_HSYNC_PERCENTAGE 8 + + float HBlankPercentage; + int VSyncAndBackPorch, VBackPorch; + int HBlank; + + /* 8. Estimated Horizontal period */ + HPeriod = ((float)(1000000.0 / VFieldRate - CVT_MIN_VSYNC_BP)) + / (VDisplayRnd + 2 * VMargin + CVT_MIN_V_PORCH + Interlace); + + /* 9. Find number of lines in sync + backporch */ + if ((int)(CVT_MIN_VSYNC_BP / HPeriod) + 1 < VSync + CVT_MIN_V_PORCH) + VSyncAndBackPorch = VSync + CVT_MIN_V_PORCH; + else + VSyncAndBackPorch = (int)(CVT_MIN_VSYNC_BP / HPeriod) + 1; + + /* 10. Find number of lines in back porch */ + VBackPorch = VSyncAndBackPorch - VSync; + (void) VBackPorch; + + /* 11. Find total number of lines in vertical field */ + Mode.VTotal = (int)(VDisplayRnd + 2 * VMargin + VSyncAndBackPorch + Interlace + CVT_MIN_V_PORCH); + + /* 5) Definition of Horizontal blanking time limitation */ + /* Gradient (%/kHz) - default 600 */ +#define CVT_M_FACTOR 600 + + /* Offset (%) - default 40 */ +#define CVT_C_FACTOR 40 + + /* Blanking time scaling factor - default 128 */ +#define CVT_K_FACTOR 128 + + /* Scaling factor weighting - default 20 */ +#define CVT_J_FACTOR 20 + +#define CVT_M_PRIME (CVT_M_FACTOR * CVT_K_FACTOR / 256) +#define CVT_C_PRIME ((CVT_C_FACTOR - CVT_J_FACTOR) * CVT_K_FACTOR / 256 + CVT_J_FACTOR) + + /* 12. Find ideal blanking duty cycle from formula */ + HBlankPercentage = CVT_C_PRIME - CVT_M_PRIME * HPeriod / 1000.0; + + /* 13. Blanking time */ + if (HBlankPercentage < 20) + HBlankPercentage = 20; + + HBlank = (int)(Mode.HDisplay * HBlankPercentage / (100.0 - HBlankPercentage)); + HBlank -= HBlank % (2 * CVT_H_GRANULARITY); + + /* 14. Find total number of pixels in a line. */ + Mode.HTotal = Mode.HDisplay + HBlank; + + /* Fill in HSync values */ + Mode.HSyncEnd = Mode.HDisplay + HBlank / 2; + + Mode.HSyncStart = Mode.HSyncEnd - (Mode.HTotal * CVT_HSYNC_PERCENTAGE) / 100; + Mode.HSyncStart += CVT_H_GRANULARITY - Mode.HSyncStart % CVT_H_GRANULARITY; + + /* Fill in VSync values */ + Mode.VSyncStart = Mode.VDisplay + CVT_MIN_V_PORCH; + Mode.VSyncEnd = Mode.VSyncStart + VSync; + + } + else { /* Reduced blanking */ + /* Minimum vertical blanking interval time (µs) - default 460 */ +#define CVT_RB_MIN_VBLANK 460.0 + + /* Fixed number of clocks for horizontal sync */ +#define CVT_RB_H_SYNC 32.0 + + /* Fixed number of clocks for horizontal blanking */ +#define CVT_RB_H_BLANK 160.0 + + /* Fixed number of lines for vertical front porch - default 3 */ +#define CVT_RB_VFPORCH 3 + + int VBILines; + + /* 8. Estimate Horizontal period. */ + HPeriod = ((float)(1000000.0 / VFieldRate - CVT_RB_MIN_VBLANK)) / (VDisplayRnd + 2 * VMargin); + + /* 9. Find number of lines in vertical blanking */ + VBILines = (int)((float)CVT_RB_MIN_VBLANK / HPeriod + 1); + + /* 10. Check if vertical blanking is sufficient */ + if (VBILines < CVT_RB_VFPORCH + VSync + CVT_MIN_V_BPORCH) + VBILines = CVT_RB_VFPORCH + VSync + CVT_MIN_V_BPORCH; + + /* 11. Find total number of lines in vertical field */ + Mode.VTotal = (int)(VDisplayRnd + 2 * VMargin + Interlace + VBILines); + + /* 12. Find total number of pixels in a line */ + Mode.HTotal = (int)(Mode.HDisplay + CVT_RB_H_BLANK); + + /* Fill in HSync values */ + Mode.HSyncEnd = (int)(Mode.HDisplay + CVT_RB_H_BLANK / 2); + Mode.HSyncStart = (int)(Mode.HSyncEnd - CVT_RB_H_SYNC); + + /* Fill in VSync values */ + Mode.VSyncStart = Mode.VDisplay + CVT_RB_VFPORCH; + Mode.VSyncEnd = Mode.VSyncStart + VSync; + } + /* 15/13. Find pixel clock frequency (kHz for xf86) */ + Mode.Clock = (int)(Mode.HTotal * 1000.0 / HPeriod); + Mode.Clock -= Mode.Clock % CVT_CLOCK_STEP; + + /* 16/14. Find actual Horizontal Frequency (kHz) */ + Mode.HSync = (float)Mode.Clock / (float)Mode.HTotal; + + /* 17/15. Find actual Field rate */ + Mode.VRefresh = (1000.0 * (float)Mode.Clock) / (float)(Mode.HTotal * Mode.VTotal); + + /* 18/16. Find actual vertical frame frequency */ + /* ignore - just set the mode flag for interlaced */ + if (Interlaced) + Mode.VTotal *= 2; + +#if 0 + XNFasprintf(&tmp, "%dx%d", HDisplay, VDisplay); + Mode->name = tmp; + + if (Reduced) + Mode->Flags |= V_PHSYNC | V_NVSYNC; + else + Mode->Flags |= V_NHSYNC | V_PVSYNC; + + if (Interlaced) + Mode->Flags |= V_INTERLACE; +#endif + + return Mode; +} |