wmesa.c

Mesa is an open-source implementation of the OpenGL specification - a system for rendering interacti

/*
 * Windows (Win32/Win64) device driver for Mesa
 *
 */

#include "wmesadef.h"
#include "colors.h"
#include <GL/wmesa.h>
#include <winuser.h>
#include "context.h"
#include "extensions.h"
#include "framebuffer.h"
#include "renderbuffer.h"
#include "drivers/common/driverfuncs.h"
#include "vbo/vbo.h"
#include "swrast/swrast.h"
#include "swrast_setup/swrast_setup.h"
#include "tnl/tnl.h"
#include "tnl/t_context.h"
#include "tnl/t_pipeline.h"


/* linked list of our Framebuffers (windows) */
static WMesaFramebuffer FirstFramebuffer = NULL;


/**
 * Create a new WMesaFramebuffer object which will correspond to the
 * given HDC (Window handle).
 */
WMesaFramebuffer
wmesa_new_framebuffer(HDC hdc, GLvisual *visual)
{
    WMesaFramebuffer pwfb
        = (WMesaFramebuffer) malloc(sizeof(struct wmesa_framebuffer));
    if (pwfb) {
        _mesa_initialize_framebuffer(&pwfb->Base, visual);
        pwfb->hDC = hdc;
        /* insert at head of list */
        pwfb->next = FirstFramebuffer;
        FirstFramebuffer = pwfb;
    }
    return pwfb;
}

/**
 * Given an hdc, free the corresponding WMesaFramebuffer
 */
void
wmesa_free_framebuffer(HDC hdc)
{
    WMesaFramebuffer pwfb, prev;
    for (pwfb = FirstFramebuffer; pwfb; pwfb = pwfb->next) {
        if (pwfb->hDC == hdc)
            break;
	prev = pwfb;
    }
    if (pwfb) {
	if (pwfb == FirstFramebuffer)
	    FirstFramebuffer = pwfb->next;
	else
	    prev->next = pwfb->next;
	free(pwfb);
    }
}

/**
 * Given an hdc, return the corresponding WMesaFramebuffer
 */
WMesaFramebuffer
wmesa_lookup_framebuffer(HDC hdc)
{
    WMesaFramebuffer pwfb;
    for (pwfb = FirstFramebuffer; pwfb; pwfb = pwfb->next) {
        if (pwfb->hDC == hdc)
            return pwfb;
    }
    return NULL;
}


/**
 * Given a GLframebuffer, return the corresponding WMesaFramebuffer.
 */
static WMesaFramebuffer wmesa_framebuffer(GLframebuffer *fb)
{
    return (WMesaFramebuffer) fb;
}


/**
 * Given a GLcontext, return the corresponding WMesaContext.
 */
static WMesaContext wmesa_context(const GLcontext *ctx)
{
    return (WMesaContext) ctx;
}


/*
 * Every driver should implement a GetString function in order to
 * return a meaningful GL_RENDERER string.
 */
static const GLubyte *wmesa_get_string(GLcontext *ctx, GLenum name)
{
    return (name == GL_RENDERER) ? 
	(GLubyte *) "Mesa Windows GDI Driver" : NULL;
}


/*
 * Determine the pixel format based on the pixel size.
 */
static void wmSetPixelFormat(WMesaFramebuffer pwfb, HDC hDC)
{
    pwfb->cColorBits = GetDeviceCaps(hDC, BITSPIXEL);

    /* Only 16 and 32 bit targets are supported now */
    assert(pwfb->cColorBits == 0 ||
	   pwfb->cColorBits == 16 || 
	   pwfb->cColorBits == 24 || 
	   pwfb->cColorBits == 32);

    switch(pwfb->cColorBits){
    case 8:
	pwfb->pixelformat = PF_INDEX8;
	break;
    case 16:
	pwfb->pixelformat = PF_5R6G5B;
	break;
    case 24:
    case 32:
	pwfb->pixelformat = PF_8R8G8B;
	break;
    default:
	pwfb->pixelformat = PF_BADFORMAT;
    }
}


/**
 * Create DIB for back buffer.
 * We write into this memory with the span routines and then blit it
 * to the window on a buffer swap.
 */
BOOL wmCreateBackingStore(WMesaFramebuffer pwfb, long lxSize, long lySize)
{
    HDC          hdc = pwfb->hDC;
    LPBITMAPINFO pbmi = &(pwfb->bmi);
    HDC          hic;

    pbmi->bmiHeader.biSize = sizeof(BITMAPINFOHEADER);
    pbmi->bmiHeader.biWidth = lxSize;
    pbmi->bmiHeader.biHeight= -lySize;
    pbmi->bmiHeader.biPlanes = 1;
    pbmi->bmiHeader.biBitCount = GetDeviceCaps(pwfb->hDC, BITSPIXEL);
    pbmi->bmiHeader.biCompression = BI_RGB;
    pbmi->bmiHeader.biSizeImage = 0;
    pbmi->bmiHeader.biXPelsPerMeter = 0;
    pbmi->bmiHeader.biYPelsPerMeter = 0;
    pbmi->bmiHeader.biClrUsed = 0;
    pbmi->bmiHeader.biClrImportant = 0;
    
    pwfb->cColorBits = pbmi->bmiHeader.biBitCount;
    pwfb->ScanWidth = (lxSize * (pwfb->cColorBits / 8) + 3) & ~3;
    
    hic = CreateIC("display", NULL, NULL, NULL);
    pwfb->dib_hDC = CreateCompatibleDC(hic);
    
    pwfb->hbmDIB = CreateDIBSection(hic,
				   &pwfb->bmi,
				   DIB_RGB_COLORS,
				   (void **)&(pwfb->pbPixels),
				   0,
				   0);
    pwfb->hOldBitmap = SelectObject(pwfb->dib_hDC, pwfb->hbmDIB);
    
    DeleteDC(hic);

    wmSetPixelFormat(pwfb, pwfb->hDC);
    return TRUE;
}


static wmDeleteBackingStore(WMesaFramebuffer pwfb)
{
    if (pwfb->hbmDIB) {
	SelectObject(pwfb->dib_hDC, pwfb->hOldBitmap);
	DeleteDC(pwfb->dib_hDC);
	DeleteObject(pwfb->hbmDIB);
    }
}


/**
 * Find the width and height of the window named by hdc.
 */
static void
get_window_size(HDC hdc, GLuint *width, GLuint *height)
{
    if (WindowFromDC(hdc)) {
        RECT rect;
        GetClientRect(WindowFromDC(hdc), &rect);
        *width = rect.right - rect.left;
        *height = rect.bottom - rect.top;
    }
    else { /* Memory context */
        /* From contributed code - use the size of the desktop
         * for the size of a memory context (?) */
        *width = GetDeviceCaps(hdc, HORZRES);
        *height = GetDeviceCaps(hdc, VERTRES);
    }
}


static void
wmesa_get_buffer_size(GLframebuffer *buffer, GLuint *width, GLuint *height)
{
    WMesaFramebuffer pwfb = wmesa_framebuffer(buffer);
    get_window_size(pwfb->hDC, width, height);
}


static void wmesa_flush(GLcontext *ctx)
{
    WMesaContext pwc = wmesa_context(ctx);
    WMesaFramebuffer pwfb = wmesa_framebuffer(ctx->WinSysDrawBuffer);

    if (ctx->Visual.doubleBufferMode == 1) {
	BitBlt(pwfb->hDC, 0, 0, pwfb->Base.Width, pwfb->Base.Height,
	       pwfb->dib_hDC, 0, 0, SRCCOPY);
    }
    else {
	/* Do nothing for single buffer */
    }
}


/**********************************************************************/
/*****                   CLEAR Functions                          *****/
/**********************************************************************/

/* If we do not implement these, Mesa clears the buffers via the pixel
 * span writing interface, which is very slow for a clear operation.
 */

/*
 * Set the color index used to clear the color buffer.
 */
static void clear_index(GLcontext *ctx, GLuint index)
{
    WMesaContext pwc = wmesa_context(ctx);
    /* Note that indexed mode is not supported yet */
    pwc->clearColorRef = RGB(0,0,0);
}

/*
 * Set the color used to clear the color buffer.
 */
static void clear_color(GLcontext *ctx, const GLfloat color[4])
{
    WMesaContext pwc = wmesa_context(ctx);
    WMesaFramebuffer pwfb = wmesa_framebuffer(ctx->DrawBuffer);
    GLubyte col[3];
    UINT    bytesPerPixel = pwfb->cColorBits / 8; 

    CLAMPED_FLOAT_TO_UBYTE(col[0], color[0]);
    CLAMPED_FLOAT_TO_UBYTE(col[1], color[1]);
    CLAMPED_FLOAT_TO_UBYTE(col[2], color[2]);
    pwc->clearColorRef = RGB(col[0], col[1], col[2]);
    DeleteObject(pwc->clearPen);
    DeleteObject(pwc->clearBrush);
    pwc->clearPen = CreatePen(PS_SOLID, 1, pwc->clearColorRef); 
    pwc->clearBrush = CreateSolidBrush(pwc->clearColorRef); 
}


/* 
 * Clear the specified region of the color buffer using the clear color 
 * or index as specified by one of the two functions above. 
 * 
 * This procedure clears either the front and/or the back COLOR buffers. 
 * Only the "left" buffer is cleared since we are not stereo. 
 * Clearing of the other non-color buffers is left to the swrast. 
 */ 

static void clear(GLcontext *ctx, GLbitfield mask)
{
#define FLIP(Y)  (ctx->DrawBuffer->Height - (Y) - 1)
    const GLint x = ctx->DrawBuffer->_Xmin;
    const GLint y = ctx->DrawBuffer->_Ymin;
    const GLint height = ctx->DrawBuffer->_Ymax - ctx->DrawBuffer->_Ymin;
    const GLint width  = ctx->DrawBuffer->_Xmax - ctx->DrawBuffer->_Xmin;

    WMesaContext pwc = wmesa_context(ctx);
    WMesaFramebuffer pwfb = wmesa_framebuffer(ctx->DrawBuffer);
    int done = 0;

    /* Let swrast do all the work if the masks are not set to
     * clear all channels. */
    if (ctx->Color.ColorMask[0] != 0xff ||
	ctx->Color.ColorMask[1] != 0xff ||
	ctx->Color.ColorMask[2] != 0xff ||
	ctx->Color.ColorMask[3] != 0xff) {
	_swrast_Clear(ctx, mask);
	return;
    }

    /* Back buffer */
    if (mask & BUFFER_BIT_BACK_LEFT) { 
	
	int     i, rowSize; 
	UINT    bytesPerPixel = pwfb->cColorBits / 8; 
	LPBYTE  lpb, clearRow;
	LPWORD  lpw;
	BYTE    bColor; 
	WORD    wColor; 
	BYTE    r, g, b; 
	DWORD   dwColor; 
	LPDWORD lpdw; 
	
	/* Try for a fast clear - clearing entire buffer with a single
	 * byte value. */
	if (width == ctx->DrawBuffer->Width &&
            height == ctx->DrawBuffer->Height) { /* entire buffer */
	    /* Now check for an easy clear value */
	    switch (bytesPerPixel) {
	    case 1:
		bColor = BGR8(GetRValue(pwc->clearColorRef), 
			      GetGValue(pwc->clearColorRef), 
			      GetBValue(pwc->clearColorRef));
		memset(pwfb->pbPixels, bColor, 
		       pwfb->ScanWidth * height);
		done = 1;
		break;
	    case 2:
		wColor = BGR16(GetRValue(pwc->clearColorRef), 
			       GetGValue(pwc->clearColorRef), 
			       GetBValue(pwc->clearColorRef)); 
		if (((wColor >> 8) & 0xff) == (wColor & 0xff)) {
		    memset(pwfb->pbPixels, wColor & 0xff, 
			   pwfb->ScanWidth * height);
		    done = 1;
		}
		break;
	    case 3:
		/* fall through */
	    case 4:
		if (GetRValue(pwc->clearColorRef) == 
		    GetGValue(pwc->clearColorRef) &&
		    GetRValue(pwc->clearColorRef) == 
		    GetBValue(pwc->clearColorRef)) {
		    memset(pwfb->pbPixels, 
			   GetRValue(pwc->clearColorRef), 
			   pwfb->ScanWidth * height);
		    done = 1;
		}
		break;
	    default:
		break;
	    }
	} /* all */

	if (!done) {
	    /* Need to clear a row at a time.  Begin by setting the first
	     * row in the area to be cleared to the clear color. */
	    
	    clearRow = pwfb->pbPixels + 
		pwfb->ScanWidth * FLIP(y) +
		bytesPerPixel * x; 
	    switch (bytesPerPixel) {
	    case 1:
		lpb = clearRow;
		bColor = BGR8(GetRValue(pwc->clearColorRef), 
			      GetGValue(pwc->clearColorRef), 
			      GetBValue(pwc->clearColorRef));
		memset(lpb, bColor, width);
		break;
	    case 2:
		lpw = (LPWORD)clearRow;
		wColor = BGR16(GetRValue(pwc->clearColorRef), 
			       GetGValue(pwc->clearColorRef), 
			       GetBValue(pwc->clearColorRef)); 
		for (i=0; i<width; i++)
		    *lpw++ = wColor;
		break;
	    case 3: 
		lpb = clearRow;
		r = GetRValue(pwc->clearColorRef); 
		g = GetGValue(pwc->clearColorRef); 
		b = GetBValue(pwc->clearColorRef); 
		for (i=0; i<width; i++) {
		    *lpb++ = b; 
		    *lpb++ = g; 
		    *lpb++ = r; 
		} 
		break;
	    case 4: 
		lpdw = (LPDWORD)clearRow; 
		dwColor = BGR32(GetRValue(pwc->clearColorRef), 
				GetGValue(pwc->clearColorRef), 
				GetBValue(pwc->clearColorRef)); 
		for (i=0; i<width; i++)
		    *lpdw++ = dwColor;
		break;
	    default:
		break;
	    } /* switch */
	    
	    /* copy cleared row to other rows in buffer */
	    lpb = clearRow - pwfb->ScanWidth;
	    rowSize = width * bytesPerPixel;
	    for (i=1; i<height; i++) { 
		memcpy(lpb, clearRow, rowSize); 
		lpb -= pwfb->ScanWidth; 
	    } 
	} /* not done */
	mask &= ~BUFFER_BIT_BACK_LEFT;
    } /* back buffer */ 

    /* front buffer */
    if (mask & BUFFER_BIT_FRONT_LEFT) { 
	HDC DC = pwc->hDC; 
	HPEN Old_Pen = SelectObject(DC, pwc->clearPen); 
	HBRUSH Old_Brush = SelectObject(DC, pwc->clearBrush);
	Rectangle(DC,
		  x,
		  FLIP(y) + 1,
		  x + width + 1,
		  FLIP(y) - height + 1);
	SelectObject(DC, Old_Pen); 
	SelectObject(DC, Old_Brush); 
	mask &= ~BUFFER_BIT_FRONT_LEFT;
    } /* front buffer */ 
    
    /* Call swrast if there is anything left to clear (like DEPTH) */ 
    if (mask) 
	_swrast_Clear(ctx, mask);