kitty/glfw/monitor.c

//========================================================================
// GLFW 3.4 - www.glfw.org
//------------------------------------------------------------------------
// Copyright (c) 2002-2006 Marcus Geelnard
// Copyright (c) 2006-2019 Camilla Löwy <elmindreda@glfw.org>
//
// This software is provided 'as-is', without any express or implied
// warranty. In no event will the authors be held liable for any damages
// arising from the use of this software.
//
// Permission is granted to anyone to use this software for any purpose,
// including commercial applications, and to alter it and redistribute it
// freely, subject to the following restrictions:
//
// 1. The origin of this software must not be misrepresented; you must not
//    claim that you wrote the original software. If you use this software
//    in a product, an acknowledgment in the product documentation would
//    be appreciated but is not required.
//
// 2. Altered source versions must be plainly marked as such, and must not
//    be misrepresented as being the original software.
//
// 3. This notice may not be removed or altered from any source
//    distribution.
//
//========================================================================
// Please use C89 style variable declarations in this file because VS 2010
//========================================================================

#include "internal.h"

#include <assert.h>
#include <math.h>
#include <float.h>
#include <string.h>
#include <stdlib.h>
#include <limits.h>


// Lexically compare video modes, used by qsort
//
static int
compareVideoModes(const void *fp, const void *sp) {
    const GLFWvidmode *fm = fp;
    const GLFWvidmode *sm = sp;
    const int fbpp = fm->redBits + fm->greenBits + fm->blueBits;
    const int sbpp = sm->redBits + sm->greenBits + sm->blueBits;
    const int farea = fm->width * fm->height;
    const int sarea = sm->width * sm->height;

    // First sort on color bits per pixel
    if (fbpp != sbpp) return fbpp - sbpp;

    // Then sort on screen area
    if (farea != sarea) return farea - sarea;

    // Then sort on width
    if (fm->width != sm->width) return fm->width - sm->width;

    // Lastly sort on refresh rate
    return fm->refreshRate - sm->refreshRate;
}

// Retrieves the available modes for the specified monitor
//
static bool
refreshVideoModes(_GLFWmonitor *monitor) {
    int modeCount;
    GLFWvidmode *modes;

    if (monitor->modes) return true;

    modes = _glfwPlatformGetVideoModes(monitor, &modeCount);
    if (!modes) return false;

    qsort(modes, modeCount, sizeof(modes[0]), compareVideoModes);

    free(monitor->modes);
    monitor->modes = modes;
    monitor->modeCount = modeCount;

    return true;
}


//////////////////////////////////////////////////////////////////////////
//////                         GLFW event API                       //////
//////////////////////////////////////////////////////////////////////////

// Notifies shared code of a monitor connection or disconnection
//
void
_glfwInputMonitor(_GLFWmonitor *monitor, int action, int placement) {
    if (action == GLFW_CONNECTED) {
        _glfw.monitorCount++;
        _glfw.monitors = realloc(_glfw.monitors, sizeof(_GLFWmonitor *) * _glfw.monitorCount);

        if (placement == _GLFW_INSERT_FIRST) {
            memmove(_glfw.monitors + 1, _glfw.monitors, ((size_t)_glfw.monitorCount - 1) * sizeof(_GLFWmonitor *));
            _glfw.monitors[0] = monitor;
        } else _glfw.monitors[_glfw.monitorCount - 1] = monitor;
    } else if (action == GLFW_DISCONNECTED) {
        int i;
        _GLFWwindow *window;

        for (window = _glfw.windowListHead; window; window = window->next) {
            if (window->monitor == monitor) {
                int width, height, xoff, yoff;
                _glfwPlatformGetWindowSize(window, &width, &height);
                _glfwPlatformSetWindowMonitor(window, NULL, 0, 0, width, height, 0);
                _glfwPlatformGetWindowFrameSize(window, &xoff, &yoff, NULL, NULL);
                _glfwPlatformSetWindowPos(window, xoff, yoff);
            }
        }

        for (i = 0; i < _glfw.monitorCount; i++) {
            if (_glfw.monitors[i] == monitor) {
                remove_i_from_array(_glfw.monitors, i, _glfw.monitorCount);
                break;
            }
        }
    }

    if (_glfw.callbacks.monitor) _glfw.callbacks.monitor((GLFWmonitor *)monitor, action);

    if (action == GLFW_DISCONNECTED) _glfwFreeMonitor(monitor);
}

// Notifies shared code that a full screen window has acquired or released
// a monitor
//
void
_glfwInputMonitorWindow(_GLFWmonitor *monitor, _GLFWwindow *window) {
    monitor->window = window;
}


//////////////////////////////////////////////////////////////////////////
//////                       GLFW internal API                      //////
//////////////////////////////////////////////////////////////////////////

// Allocates and returns a monitor object with the specified name and dimensions
//
_GLFWmonitor *
_glfwAllocMonitor(const char *name, int widthMM, int heightMM) {
    _GLFWmonitor *monitor = calloc(1, sizeof(_GLFWmonitor));
    monitor->widthMM = widthMM;
    monitor->heightMM = heightMM;

    if (name) monitor->name = _glfw_strdup(name);

    return monitor;
}

// Frees a monitor object and any data associated with it
//
void
_glfwFreeMonitor(_GLFWmonitor *monitor) {
    if (monitor == NULL) return;

    _glfwPlatformFreeMonitor(monitor);

    _glfwFreeGammaArrays(&monitor->originalRamp);
    _glfwFreeGammaArrays(&monitor->currentRamp);

    free(monitor->modes);
    free((void *)monitor->name);
    free((void *)monitor->description);
    free(monitor);
}

// Allocates red, green and blue value arrays of the specified size
//
void
_glfwAllocGammaArrays(GLFWgammaramp *ramp, unsigned int size) {
    ramp->red = calloc(size, sizeof(unsigned short));
    ramp->green = calloc(size, sizeof(unsigned short));
    ramp->blue = calloc(size, sizeof(unsigned short));
    ramp->size = size;
}

// Frees the red, green and blue value arrays and clears the struct
//
void
_glfwFreeGammaArrays(GLFWgammaramp *ramp) {
    free(ramp->red);
    free(ramp->green);
    free(ramp->blue);

    memset(ramp, 0, sizeof(GLFWgammaramp));
}

// Chooses the video mode most closely matching the desired one
//
const GLFWvidmode *
_glfwChooseVideoMode(_GLFWmonitor *monitor, const GLFWvidmode *desired) {
    int i;
    unsigned int sizeDiff, leastSizeDiff = UINT_MAX;
    unsigned int rateDiff, leastRateDiff = UINT_MAX;
    unsigned int colorDiff, leastColorDiff = UINT_MAX;
    const GLFWvidmode *current;
    const GLFWvidmode *closest = NULL;

    if (!refreshVideoModes(monitor)) return NULL;

    for (i = 0; i < monitor->modeCount; i++) {
        current = monitor->modes + i;

        colorDiff = 0;

        if (desired->redBits != GLFW_DONT_CARE) colorDiff += abs(current->redBits - desired->redBits);
        if (desired->greenBits != GLFW_DONT_CARE) colorDiff += abs(current->greenBits - desired->greenBits);
        if (desired->blueBits != GLFW_DONT_CARE) colorDiff += abs(current->blueBits - desired->blueBits);

        sizeDiff = abs(
            (current->width - desired->width) * (current->width - desired->width) + (current->height - desired->height) * (current->height - desired->height));

        if (desired->refreshRate != GLFW_DONT_CARE) rateDiff = abs(current->refreshRate - desired->refreshRate);
        else rateDiff = UINT_MAX - current->refreshRate;

        if ((colorDiff < leastColorDiff) || (colorDiff == leastColorDiff && sizeDiff < leastSizeDiff) ||
            (colorDiff == leastColorDiff && sizeDiff == leastSizeDiff && rateDiff < leastRateDiff)) {
            closest = current;
            leastSizeDiff = sizeDiff;
            leastRateDiff = rateDiff;
            leastColorDiff = colorDiff;
        }
    }

    return closest;
}

// Performs lexical comparison between two @ref GLFWvidmode structures
//
int
_glfwCompareVideoModes(const GLFWvidmode *fm, const GLFWvidmode *sm) {
    return compareVideoModes(fm, sm);
}

// Splits a color depth into red, green and blue bit depths
//
void
_glfwSplitBPP(int bpp, int *red, int *green, int *blue) {
    int delta;

    // We assume that by 32 the user really meant 24
    if (bpp == 32) bpp = 24;

    // Convert "bits per pixel" to red, green & blue sizes

    *red = *green = *blue = bpp / 3;
    delta = bpp - (*red * 3);
    if (delta >= 1) *green = *green + 1;

    if (delta == 2) *red = *red + 1;
}


//////////////////////////////////////////////////////////////////////////
//////                        GLFW public API                       //////
//////////////////////////////////////////////////////////////////////////

GLFWAPI GLFWmonitor **
glfwGetMonitors(int *count) {
    assert(count != NULL);

    *count = 0;

    _GLFW_REQUIRE_INIT_OR_RETURN(NULL);

    *count = _glfw.monitorCount;
    return (GLFWmonitor **)_glfw.monitors;
}

GLFWAPI GLFWmonitor *
glfwGetPrimaryMonitor(void) {
    _GLFW_REQUIRE_INIT_OR_RETURN(NULL);

    if (!_glfw.monitorCount) return NULL;

    return (GLFWmonitor *)_glfw.monitors[0];
}

GLFWAPI void
glfwGetMonitorPos(GLFWmonitor *handle, int *xpos, int *ypos) {
    _GLFWmonitor *monitor = (_GLFWmonitor *)handle;
    assert(monitor != NULL);

    if (xpos) *xpos = 0;
    if (ypos) *ypos = 0;

    _GLFW_REQUIRE_INIT();

    _glfwPlatformGetMonitorPos(monitor, xpos, ypos);
}

GLFWAPI void
glfwGetMonitorWorkarea(GLFWmonitor *handle, int *xpos, int *ypos, int *width, int *height) {
    _GLFWmonitor *monitor = (_GLFWmonitor *)handle;
    assert(monitor != NULL);

    if (xpos) *xpos = 0;
    if (ypos) *ypos = 0;
    if (width) *width = 0;
    if (height) *height = 0;

    _GLFW_REQUIRE_INIT();

    _glfwPlatformGetMonitorWorkarea(monitor, xpos, ypos, width, height);
}

GLFWAPI void
glfwGetMonitorPhysicalSize(GLFWmonitor *handle, int *widthMM, int *heightMM) {
    _GLFWmonitor *monitor = (_GLFWmonitor *)handle;
    assert(monitor != NULL);

    if (widthMM) *widthMM = 0;
    if (heightMM) *heightMM = 0;

    _GLFW_REQUIRE_INIT();

    if (widthMM) *widthMM = monitor->widthMM;
    if (heightMM) *heightMM = monitor->heightMM;
}

GLFWAPI void
glfwGetMonitorContentScale(GLFWmonitor *handle, float *xscale, float *yscale) {
    _GLFWmonitor *monitor = (_GLFWmonitor *)handle;
    assert(monitor != NULL);

    if (xscale) *xscale = 0.f;
    if (yscale) *yscale = 0.f;

    _GLFW_REQUIRE_INIT();
    _glfwPlatformGetMonitorContentScale(monitor, xscale, yscale);
}

GLFWAPI const char *
glfwGetMonitorName(GLFWmonitor *handle) {
    _GLFWmonitor *monitor = (_GLFWmonitor *)handle;
    assert(monitor != NULL);

    _GLFW_REQUIRE_INIT_OR_RETURN(NULL);
    return monitor->name ? monitor->name : "";
}

GLFWAPI const char *
glfwGetMonitorDescription(GLFWmonitor *handle) {
    _GLFWmonitor *monitor = (_GLFWmonitor *)handle;
    assert(monitor != NULL);

    _GLFW_REQUIRE_INIT_OR_RETURN(NULL);
    return monitor->description ? monitor->description : "";
}


GLFWAPI void
glfwSetMonitorUserPointer(GLFWmonitor *handle, void *pointer) {
    _GLFWmonitor *monitor = (_GLFWmonitor *)handle;
    assert(monitor != NULL);

    _GLFW_REQUIRE_INIT();
    monitor->userPointer = pointer;
}

GLFWAPI void *
glfwGetMonitorUserPointer(GLFWmonitor *handle) {
    _GLFWmonitor *monitor = (_GLFWmonitor *)handle;
    assert(monitor != NULL);

    _GLFW_REQUIRE_INIT_OR_RETURN(NULL);
    return monitor->userPointer;
}

GLFWAPI GLFWmonitorfun
glfwSetMonitorCallback(GLFWmonitorfun cbfun) {
    _GLFW_REQUIRE_INIT_OR_RETURN(NULL);
    _GLFW_SWAP_POINTERS(_glfw.callbacks.monitor, cbfun);
    return cbfun;
}

GLFWAPI const GLFWvidmode *
glfwGetVideoModes(GLFWmonitor *handle, int *count) {
    _GLFWmonitor *monitor = (_GLFWmonitor *)handle;
    assert(monitor != NULL);
    assert(count != NULL);

    *count = 0;

    _GLFW_REQUIRE_INIT_OR_RETURN(NULL);

    if (!refreshVideoModes(monitor)) return NULL;

    *count = monitor->modeCount;
    return monitor->modes;
}

GLFWAPI const GLFWvidmode *
glfwGetVideoMode(GLFWmonitor *handle) {
    _GLFWmonitor *monitor = (_GLFWmonitor *)handle;
    assert(monitor != NULL);

    _GLFW_REQUIRE_INIT_OR_RETURN(NULL);

    if (!_glfwPlatformGetVideoMode(monitor, &monitor->currentMode)) return NULL;
    return &monitor->currentMode;
}

GLFWAPI void
glfwSetGamma(GLFWmonitor *handle, float gamma) {
    unsigned int i;
    unsigned short *values;
    GLFWgammaramp ramp;
    const GLFWgammaramp *original;
    assert(handle != NULL);
    assert(gamma > 0.f);
    assert(gamma <= FLT_MAX);

    _GLFW_REQUIRE_INIT();

    if (gamma != gamma || gamma <= 0.f || gamma > FLT_MAX) {
        _glfwInputError(GLFW_INVALID_VALUE, "Invalid gamma value %f", gamma);
        return;
    }

    original = glfwGetGammaRamp(handle);
    if (!original) return;

    values = calloc(original->size, sizeof(unsigned short));

    for (i = 0; i < original->size; i++) {
        float value;

        // Calculate intensity
        value = i / (float)(original->size - 1);
        // Apply gamma curve
        value = powf(value, 1.f / gamma) * 65535.f + 0.5f;
        // Clamp to value range
        value = fminf(value, 65535.f);

        values[i] = (unsigned short)value;
    }

    ramp.red = values;
    ramp.green = values;
    ramp.blue = values;
    ramp.size = original->size;

    glfwSetGammaRamp(handle, &ramp);
    free(values);
}

GLFWAPI const GLFWgammaramp *
glfwGetGammaRamp(GLFWmonitor *handle) {
    _GLFWmonitor *monitor = (_GLFWmonitor *)handle;
    assert(monitor != NULL);

    _GLFW_REQUIRE_INIT_OR_RETURN(NULL);

    _glfwFreeGammaArrays(&monitor->currentRamp);
    if (!_glfwPlatformGetGammaRamp(monitor, &monitor->currentRamp)) return NULL;

    return &monitor->currentRamp;
}

GLFWAPI void
glfwSetGammaRamp(GLFWmonitor *handle, const GLFWgammaramp *ramp) {
    _GLFWmonitor *monitor = (_GLFWmonitor *)handle;
    assert(monitor != NULL);
    assert(ramp != NULL);
    assert(ramp->size > 0);
    assert(ramp->red != NULL);
    assert(ramp->green != NULL);
    assert(ramp->blue != NULL);

    if (ramp->size <= 0) {
        _glfwInputError(GLFW_INVALID_VALUE, "Invalid gamma ramp size %i", ramp->size);
        return;
    }

    _GLFW_REQUIRE_INIT();

    if (!monitor->originalRamp.size) {
        if (!_glfwPlatformGetGammaRamp(monitor, &monitor->originalRamp)) return;
    }

    _glfwPlatformSetGammaRamp(monitor, ramp);
}