Implement support for NV_path_rendering on OpenGL ES. Use
glProgramPathFragmentInputGenNV function call instead of glPathTexGenNV to
communicate transforms to fragment shader.
The intention is that the NVPR paths will be drawn with the same shader program
as non-NVPR geometry. For NVPR calls, the GPU will skip the vertex shader and
just run the fragment shader.
After program is linked, query the locations of the fragment shader inputs with
glGetResourceLocation. The location will be used to set the transforms with
glProgramPathFragmentInputGenNV.
The functions and their workings are documented in:
glProgramPathFragmentInputGenNV
https://www.opengl.org/registry/specs/NV/path_rendering.txt
(note: addition as of API version 1.3)
glGetResourceLocation
https://www.opengl.org/registry/specs/ARB/program_interface_query.txthttp://www.opengl.org/registry/doc/glspec44.core.pdf
(function is in core Open GL 4.4)
Note: glProgramPathFragmentInputGenNV could be used also for OpenGL. However,
using seems to trigger a bug in the driver. Disable this feature on OpenGL at
least until the driver is fixed and released. The bug manifests in shadertext
test, where the lower-left text pair is missing. Valgrind catches a bad read
for the test and causes the context to OOM reproducibly.
R=bsalomon@google.com, cdalton@nvidia.com, joshualitt@google.com, joshualitt@chromium.org
Author: kkinnunen@nvidia.com
Review URL: https://codereview.chromium.org/367643004
Adds GrEffect::willUseInputColor() which indicates whether or not the
input color affects the output of the effect. This is needed for
certain Xfermodes, such as kSrc_Mode. For these modes the color filter
will not use the input color.
An effect with GrEffect::willUseInputColor() true will cause all color
or coverage effects before it to be discarded, as their computations
cannot affect the output. In these cases program is marked as having
white input color.
This fixes an assert when Skia is compiled in a mode that prefers
using uniforms instead of attributes for constants. (Flags
GR_GL_USE_NV_PATH_RENDERING or GR_GL_NO_CONSTANT_ATTRIBUTES). Using
attributes hides the problem where the fragment shader does not need
input color for color filters that ignore DST part of the filter. The
assert would be hit when uniform manager tries to bind an uniform which
has been optimized away by the shader compiler.
Adds specific GrGLSLExpr4 and GrGLSLExpr1 classes. This way the GLSL
expressions like "(v - src.a)" can remain somewhat readable in form of
"(v - src.a())". The GrGLSLExpr<typename> template implements the
generic functionality, GrGLSLExprX is the specialization that exposes
the type-safe interface to this functionality.
Also adds operators so that GLSL binary operators of the form
"(float * vecX)" can be expressed in C++. Before only the equivalent
"(vecX * float)" was possible. This reverts the common blending
calculations to more conventional order, such as "(1-a) * c" instead of
"c * (1-a)".
Changes GrGLSLExpr1::OnesStr from 1 to 1.0 in order to preserve the
color filter blending formula string the same (with the exception of
variable name change).
Shaders change in case of input color being needed:
- vec4 filteredColor;
- filteredColor = (((1.0 - uFilterColor.a) * output_Stage0) + uFilterColor);
- fsColorOut = filteredColor;
+ vec4 output_Stage1;
+ { // Stage 1: ModeColorFilterEffect
+ output_Stage1 = (((1.0 - uFilterColor_Stage1.a) * output_Stage0) + uFilterColor_Stage1);
+ }
+ fsColorOut = output_Stage1;
Shaders change in case of input color being not needed:
-uniform vec4 uFilterColor;
-in vec4 vColor;
+uniform vec4 uFilterColor_Stage0;
out vec4 fsColorOut;
void main() {
- vec4 filteredColor;
- filteredColor = uFilterColor;
- fsColorOut = filteredColor;
+ vec4 output_Stage0;
+ { // Stage 0: ModeColorFilterEffect
+ output_Stage0 = uFilterColor_Stage0;
+ }
+ fsColorOut = output_Stage0;
}
R=bsalomon@google.com, robertphillips@google.com, jvanverth@google.com
Author: kkinnunen@nvidia.com
Review URL: https://codereview.chromium.org/25023003
git-svn-id: http://skia.googlecode.com/svn/trunk@11912 2bbb7eff-a529-9590-31e7-b0007b416f81
Adds a 'hasVertexCode' method to GrEffect and a 'fHasVertexCode' field
to GrGLProgramDesc::KeyHeader. Also adds a GrVertexEffect class that
effects have to inherit from in order to set the 'hasVertexCode' flag
and be able to emit vertex code, and updates the existing effects to
use it as needed.
R=bsalomon@google.com
Author: cdalton@nvidia.com
Review URL: https://codereview.chromium.org/23653059
git-svn-id: http://skia.googlecode.com/svn/trunk@11537 2bbb7eff-a529-9590-31e7-b0007b416f81
Extracts a GrCustomCoordsTextureEffect class from
GrSimpleTextureEffect. This way there are no effects that can
conditionally require a vertex shader. They either always need one or
never do. Also removes kCustom_CoordsType from the CoordsType enum in
GrEffect (that enum is really only meant for coords provided by the
framework), and updates GrSimpleTextureEffect::TestCreate to make the
effect with position as well, instead of just local coords.
R=bsalomon@google.com
Author: cdalton@nvidia.com
Review URL: https://codereview.chromium.org/24018007
git-svn-id: http://skia.googlecode.com/svn/trunk@11531 2bbb7eff-a529-9590-31e7-b0007b416f81
The current implementation is to always make a copy of the entire dst before the draw.
It will only succeed if the RT is also a texture.
Obviously, there is lots of room for improvement.
Review URL: https://codereview.chromium.org/13314002
git-svn-id: http://skia.googlecode.com/svn/trunk@8449 2bbb7eff-a529-9590-31e7-b0007b416f81
Effects can ask the builder for local coords which may or may not be distinct from positions.
GrEffectStage tracks changes to relationship between pos and local coords.
GrGLEffectMatrix and GrSingleTextureEffect can use either pos or textures as intput coords
GrSimpleTextureEffect now allows for an explicit texture coords attribute.
Review URL: https://codereview.chromium.org/12531015
git-svn-id: http://skia.googlecode.com/svn/trunk@8264 2bbb7eff-a529-9590-31e7-b0007b416f81
