[Glamor] [PATCH 5/7] Fix the problem of vertical and horizontal case error in linear gradient.

[He Junyan]

于 2012/5/15 12:51, Zhigang Gong 写道:
> On Tue, May 08, 2012 at 08:45:03AM +0800, junyan.he at linux.intel.com wrote:
>> From: Junyan He<junyan.he at linux.intel.com>
>>
>>   1. The vertical and horizontal judgement in linear
>>   gradient have problem when p1 point and p2 point
>>   distance is very small but the gradient pict have a
>>   transform matrix which will convert the X Y coordinates
>>   to small values. So the judgement is not suitable.
>>   Because this judgement's purpose is to assure the
>>   divisor not to be zero, so we simply it to enter
>>   horizontal judgement when p1 and p2's Y is same.
>>   Vertical case is deleted.
> If we have non-int transform matrix, both the vertical and
> horizontal check are invalid here, right? You may need to
> check whether we have a non-int transform matrix, and then
> choose different method to check the hor/vert condition?
It is not the case. The coordinate of P1 and P2 do not be affected by 
the matrix.
Only X and Y of the texture will be re-caculated by the matrix. So in 
the old code,
when the P1 and P2 is very close, we judge the case is vertical or 
horizontal, but
after X and Y re-caculated by the matix, P1 and P2's distance is 
enlarged, comparing
to the X Y. The re-caculated of X Y happens in the shader and the 
judgement happens
before the shader, no causes this problem.


>>   2. Delete the unused p1 p2 uniform variable.
>>
>>
>> Signed-off-by: Junyan He<junyan.he at linux.intel.com>
>> ---
>>   src/glamor_gradient.c |   28 ++++------------------------
>>   1 files changed, 4 insertions(+), 24 deletions(-)
>>
>> diff --git a/src/glamor_gradient.c b/src/glamor_gradient.c
>> index 7263c2b..12eff03 100644
>> --- a/src/glamor_gradient.c
>> +++ b/src/glamor_gradient.c
>> @@ -491,8 +491,6 @@ _glamor_create_linear_gradient_program(ScreenPtr screen, int stops_count, int dy
>>   	    "uniform mat3 transform_mat;\n"
>>   	    "uniform int repeat_type;\n"
>>   	    "uniform int hor_ver;\n"
>> -	    "uniform vec4 pt1;\n"
>> -	    "uniform vec4 pt2;\n"
>>   	    "uniform float pt_slope;\n"
>>   	    "uniform float cos_val;\n"
>>   	    "uniform float p1_distance;\n"
>> @@ -529,10 +527,6 @@ _glamor_create_linear_gradient_program(ScreenPtr screen, int stops_count, int dy
>>   	    "        distance = source_texture_trans.x;\n"
>>   	    "        _p1_distance = p1_distance * source_texture_trans.z;\n"
>>   	    "        _pt_distance = pt_distance * source_texture_trans.z;\n"
>> -	    "    } else if (hor_ver == 2) {\n"//vertical case.
>> -	    "        distance = source_texture_trans.y;\n"
>> -	    "        _p1_distance = p1_distance * source_texture_trans.z;\n"
>> -	    "        _pt_distance = pt_distance * source_texture_trans.z;\n"
>>   	    "    } \n"
>>   	    "    \n"
>>   	    "    distance = distance - _p1_distance; \n"
>> @@ -1301,8 +1295,6 @@ glamor_generate_linear_gradient_picture(ScreenPtr screen,
>>   	GLfloat n_stops_st[LINEAR_SMALL_STOPS];
>>
>>   	GLint transform_mat_uniform_location;
>> -	GLint pt1_uniform_location;
>> -	GLint pt2_uniform_location;
>>   	GLint n_stop_uniform_location;
>>   	GLint stops_uniform_location;
>>   	GLint stop0_uniform_location;
>> @@ -1369,10 +1361,6 @@ glamor_generate_linear_gradient_picture(ScreenPtr screen,
>>   	}
>>
>>   	/* Bind all the uniform vars .*/
>> -	pt1_uniform_location =
>> -	    dispatch->glGetUniformLocation(gradient_prog, "pt1");
>> -	pt2_uniform_location =
>> -	    dispatch->glGetUniformLocation(gradient_prog, "pt2");
>>   	n_stop_uniform_location =
>>   	    dispatch->glGetUniformLocation(gradient_prog, "n_stop");
>>   	pt_slope_uniform_location =
>> @@ -1460,7 +1448,6 @@ glamor_generate_linear_gradient_picture(ScreenPtr screen,
>>   	                        y_source,
>>   	                        glamor_priv->yInverted,
>>   	                        pt1);
>> -	dispatch->glUniform4fv(pt1_uniform_location, 1, pt1);
>>   	DEBUGF("pt1:(%f %f)\n", pt1[0], pt1[1]);
>>
>>   	glamor_set_normalize_pt(xscale, yscale,
>> @@ -1470,7 +1457,6 @@ glamor_generate_linear_gradient_picture(ScreenPtr screen,
>>   	                        y_source,
>>   	                        glamor_priv->yInverted,
>>   	                        pt2);
>> -	dispatch->glUniform4fv(pt2_uniform_location, 1, pt2);
>>   	DEBUGF("pt2:(%f %f)\n", pt2[0], pt2[1]);
>>
>>   	/* Set all the stops and colors to shader. */
>> @@ -1545,22 +1531,16 @@ glamor_generate_linear_gradient_picture(ScreenPtr screen,
>>   		dispatch->glUniform1i(n_stop_uniform_location, count);
>>   	}
>>
>> -	if (abs((pt2[1] - pt1[1]) / yscale)<  1.0) { // The horizontal case.
>> +	if (src_picture->pSourcePict->linear.p2.y ==
>> +	              src_picture->pSourcePict->linear.p1.y) { // The horizontal case.
>>   		dispatch->glUniform1i(hor_ver_uniform_location, 1);
>> -		DEBUGF("p1.x: %f, p2.x: %f, enter the horizontal case\n", pt1[1], pt2[1]);
>> +		DEBUGF("p1.y: %f, p2.y: %f, enter the horizontal case\n",
>> +		       pt1[1], pt2[1]);
>>
>>   		p1_distance = pt1[0];
>>   		pt_distance = (pt2[0] - p1_distance);
>>   		dispatch->glUniform1f(p1_distance_uniform_location, p1_distance);
>>   		dispatch->glUniform1f(pt_distance_uniform_location, pt_distance);
>> -	} else if (abs((pt2[0] - pt1[0]) / xscale)<  1.0) { //The vertical case.
>> -		dispatch->glUniform1i(hor_ver_uniform_location, 2);
>> -		DEBUGF("p1.y: %f, p2.y: %f, enter the vertical case\n", pt1[0], pt2[0]);
>> -
>> -		p1_distance = pt1[1];
>> -		pt_distance = (pt2[1] - p1_distance);
>> -		dispatch->glUniform1f(p1_distance_uniform_location, p1_distance);
>> -		dispatch->glUniform1f(pt_distance_uniform_location, pt_distance);
>>   	} else {
>>   		/* The slope need to compute here. In shader, the viewport set will change
>>   		   the orginal slope and the slope which is vertical to it will not be correct.*/
>> --
>> 1.7.7.6
>>
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