Descent3/renderer/SoftwareSetup.cpp

#include "RendererConfig.h"
#ifdef USE_SOFTWARE_TNL

#include <stdlib.h>
#include <string.h>
#include "3d.h"
#include "pserror.h"
#include "SoftwareInternal.h"
#include "renderer.h"

//User-specified aspect ratio, stored as w/h
static float Aspect = 0.0;

//initialize the 3d system
void g3_Init(void)
{
	atexit(g3_Close);
}

//close down the 3d system
void g3_Close(void)
{
}

//allows the program to specify an aspect ratio that overrides the renderer's
//The parameter is the w/h of the screen pixels
void g3_SetAspectRatio(float aspect)
{
	Aspect = aspect;
}

void g3_GetViewPortMatrix( float *viewMat )
{
	// extract the viewport data from the renderer
	int viewportWidth, viewportHeight;
	int viewportX, viewportY;
	rend_GetProjectionScreenParameters( viewportX, viewportY, viewportWidth, viewportHeight );

	float viewportWidthOverTwo  =  ((float)viewportWidth) * 0.5f;
	float viewportHeightOverTwo = ((float)viewportHeight) * 0.5f;

	// setup the matrix
	memset( viewMat, 0, sizeof(float) * 16 );
	viewMat[0]  = viewportWidthOverTwo;
	viewMat[5]  = -viewportHeightOverTwo;
	viewMat[12] = viewportWidthOverTwo + (float)viewportX;
	viewMat[13] = viewportHeightOverTwo + (float)viewportY;	
	viewMat[10] = viewMat[15] = 1.0f;
}

void g3_GetProjectionMatrix( float zoom, float *projMat )
{
	// get window size
	int viewportWidth, viewportHeight;
	rend_GetProjectionParameters( &viewportWidth, &viewportHeight );

	// compute aspect ratio for this ViewPort
	float screenAspect = rend_GetAspectRatio();
	if( Aspect != 0.0f )
	{
		//check for user override
		screenAspect = screenAspect * 4.0 / 3.0 / Aspect;
	}
	float s = screenAspect * ((float)viewportWidth) / ((float)viewportHeight);

	// setup the matrix
	memset( projMat, 0, sizeof(float) * 16 );

	// calculate 1/tan(fov)
	float oOT = 1.0f / zoom;

	// fill in the matrix
	projMat[0]  = oOT;
	projMat[5]  = oOT * s;
	projMat[10] =  1.0f;
	projMat[11] =  1.0f;
	projMat[14] = -1.0f;
}

void g3_GetModelViewMatrix( const vector *viewPos, const matrix *viewMatrix, float *mvMat )
{
	matrix localOrient = (*viewMatrix);
	vector localPos    = -(*viewPos);
	mvMat[0]  = localOrient.rvec.x;
	mvMat[1]  = localOrient.uvec.x;
	mvMat[2]  = localOrient.fvec.x;
	mvMat[3]  = 0.0f;
	mvMat[4]  = localOrient.rvec.y;
	mvMat[5]  = localOrient.uvec.y;
	mvMat[6]  = localOrient.fvec.y;
	mvMat[7]  = 0.0f;
	mvMat[8]  = localOrient.rvec.z;
	mvMat[9]  = localOrient.uvec.z;
	mvMat[10] = localOrient.fvec.z;
	mvMat[11] = 0.0f;
	mvMat[12] = localPos * localOrient.rvec;
	mvMat[13] = localPos * localOrient.uvec;
	mvMat[14] = localPos * localOrient.fvec;
	mvMat[15] = 1.0f;
}

void g3_TransformVert( float res[4], float pt[4], float a[4][4] )
{
	int y;
	for( y = 0; y < 4; ++y )
	{
		res[y] = (pt[0] * a[0][y]) + (pt[1] * a[1][y]) + (pt[2] * a[2][y]) + (pt[3] * a[3][y]);
	}
}

void g3_TransformMult( float res[4][4], float a[4][4], float b[4][4] )
{
	float temp[4][4];

	int x, y;
	for( y = 0; y < 4; ++y )
	{
		for( x = 0; x < 4; ++x )
		{
			temp[y][x] =	(a[y][0] * b[0][x]) +
				(a[y][1] * b[1][x]) +
				(a[y][2] * b[2][x]) +
				(a[y][3] * b[3][x]);
		}
	}
	memcpy( res, temp, 16 * sizeof(float) );
}

void g3_TransformTrans( float res[4][4], float t[4][4] )
{
	float temp[4][4];
	int y;
	for( y = 0; y < 4; ++y )
	{
		int x;
		for( x = 0; x < 4; ++x )
		{
			temp[x][y] = t[y][x];
		}
	}
	memcpy( res, temp, 16 * sizeof(float) );
}

void g3_UpdateFullTransform()
{
	// ModelView -> projection
	g3_TransformMult( gTransformFull, gTransformModelView, gTransformProjection );

	// projection  -> ViewPort
	g3_TransformMult( gTransformFull, gTransformFull, gTransformViewPort );
}

//start the frame
void g3_StartFrame(vector *view_pos,matrix *view_matrix,float zoom)
{
	// initialize the viewport transform
	g3_GetViewPortMatrix( (float*)gTransformViewPort );
	g3_GetProjectionMatrix( zoom, (float*)gTransformProjection );
	g3_GetModelViewMatrix( view_pos, view_matrix, (float*)gTransformModelView );
	g3_UpdateFullTransform();

	// get window size
	rend_GetProjectionParameters( &Window_width, &Window_height );

	//Set vars for projection
	Window_w2 = ((float)Window_width)  * 0.5f;
	Window_h2 = ((float)Window_height) * 0.5f;

	//Compute aspect ratio for this window
	float screen_aspect = rend_GetAspectRatio();
	if( Aspect != 0.0f )
	{
		//check for user override
		screen_aspect = screen_aspect * 4.0 / 3.0 / Aspect;
	}
	float s = screen_aspect * (float) Window_height / (float) Window_width;

	if( s <= 0.0f )//JEFF: Should this have been 1.0f?
	{
		//scale x
		Matrix_scale.x = s;
		Matrix_scale.y = 1.0;
	}
	else 
	{
		Matrix_scale.y = 1.0 / s;
		Matrix_scale.x = 1.0;
	}

	Matrix_scale.z = 1.0;

	//Set the view variables
	View_position   = *view_pos;
	View_zoom       =  zoom;
	Unscaled_matrix = *view_matrix;

	//Compute matrix scale for zoom and aspect ratio
	if( View_zoom <= 1.0 )
	{
		//zoom in by scaling z
		Matrix_scale.z = Matrix_scale.z * View_zoom;
	}
	else
	{
		//zoom out by scaling x and y
		float oOZ = 1.0 / View_zoom;
		Matrix_scale.x = Matrix_scale.x * oOZ;
		Matrix_scale.y = Matrix_scale.y * oOZ;
	}

	//Scale the matrix elements
	View_matrix.rvec = Unscaled_matrix.rvec * Matrix_scale.x;
	View_matrix.uvec = Unscaled_matrix.uvec * Matrix_scale.y;
	View_matrix.fvec = Unscaled_matrix.fvec * Matrix_scale.z;

	//Reset the list of free points
	InitFreePoints();

	//Reset the far clip plane
	g3_ResetFarClipZ();
}

//this doesn't do anything, but is here for completeness
void g3_EndFrame(void)
{
	//make sure temp points are free
	CheckTempPoints();
}

//get the current view position
void g3_GetViewPosition(vector *vp)
{
	*vp = View_position;
}

void g3_GetViewMatrix(matrix *mat)
{
	*mat = View_matrix;
}

void g3_GetUnscaledMatrix(matrix *mat)
{
	*mat = Unscaled_matrix;
}

// Gets the matrix scale vector
void g3_GetMatrixScale(vector *matrix_scale)
{
	*matrix_scale=Matrix_scale;
}

#endif