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authorLaurent Pinchart <laurent.pinchart@ideasonboard.com>2021-09-06 23:22:54 +0300
committerLaurent Pinchart <laurent.pinchart@ideasonboard.com>2021-09-22 11:21:49 +0300
commita3b1539869ae53a6446a1c31bdade6560f91a46b (patch)
tree72e66a1f4f06583279ce0f9a012f0512946579d2
parent5e1b7a0f6845add01a6d7842ca34f9fbb0712810 (diff)
qcam: viewfinder_gl: Support configurable stride in shaders
The RGB and YUV conversion doesn't take the stride into account, neither when creating the textures, nor when sampling them. Fix it by using the stride as the texture width, and multiplying the x coordinate in the vertex shaders by a factor to only sample the active portion of the image. Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com> Reviewed-by: Paul Elder <paul.elder@ideasonboard.com>
-rw-r--r--src/qcam/assets/shader/identity.vert4
-rw-r--r--src/qcam/viewfinder_gl.cpp54
-rw-r--r--src/qcam/viewfinder_gl.h1
3 files changed, 47 insertions, 12 deletions
diff --git a/src/qcam/assets/shader/identity.vert b/src/qcam/assets/shader/identity.vert
index 6d6f7551..12c41377 100644
--- a/src/qcam/assets/shader/identity.vert
+++ b/src/qcam/assets/shader/identity.vert
@@ -9,8 +9,10 @@ attribute vec4 vertexIn;
attribute vec2 textureIn;
varying vec2 textureOut;
+uniform float stride_factor;
+
void main(void)
{
gl_Position = vertexIn;
- textureOut = textureIn;
+ textureOut = vec2(textureIn.x * stride_factor, textureIn.y);
}
diff --git a/src/qcam/viewfinder_gl.cpp b/src/qcam/viewfinder_gl.cpp
index aeb1ea02..3ae8b03a 100644
--- a/src/qcam/viewfinder_gl.cpp
+++ b/src/qcam/viewfinder_gl.cpp
@@ -395,6 +395,7 @@ bool ViewFinderGL::createFragmentShader()
textureUniformV_ = shaderProgram_.uniformLocation("tex_v");
textureUniformStep_ = shaderProgram_.uniformLocation("tex_step");
textureUniformSize_ = shaderProgram_.uniformLocation("tex_size");
+ textureUniformStrideFactor_ = shaderProgram_.uniformLocation("stride_factor");
textureUniformBayerFirstRed_ = shaderProgram_.uniformLocation("tex_bayer_first_red");
/* Create the textures. */
@@ -464,6 +465,9 @@ void ViewFinderGL::initializeGL()
void ViewFinderGL::doRender()
{
+ /* Stride of the first plane, in pixels. */
+ unsigned int stridePixels;
+
switch (format_) {
case libcamera::formats::NV12:
case libcamera::formats::NV21:
@@ -477,7 +481,7 @@ void ViewFinderGL::doRender()
glTexImage2D(GL_TEXTURE_2D,
0,
GL_LUMINANCE,
- size_.width(),
+ stride_,
size_.height(),
0,
GL_LUMINANCE,
@@ -491,13 +495,15 @@ void ViewFinderGL::doRender()
glTexImage2D(GL_TEXTURE_2D,
0,
GL_LUMINANCE_ALPHA,
- size_.width() / horzSubSample_,
+ stride_ / horzSubSample_,
size_.height() / vertSubSample_,
0,
GL_LUMINANCE_ALPHA,
GL_UNSIGNED_BYTE,
image_->data(1).data());
shaderProgram_.setUniformValue(textureUniformU_, 1);
+
+ stridePixels = stride_;
break;
case libcamera::formats::YUV420:
@@ -507,7 +513,7 @@ void ViewFinderGL::doRender()
glTexImage2D(GL_TEXTURE_2D,
0,
GL_LUMINANCE,
- size_.width(),
+ stride_,
size_.height(),
0,
GL_LUMINANCE,
@@ -521,7 +527,7 @@ void ViewFinderGL::doRender()
glTexImage2D(GL_TEXTURE_2D,
0,
GL_LUMINANCE,
- size_.width() / horzSubSample_,
+ stride_ / horzSubSample_,
size_.height() / vertSubSample_,
0,
GL_LUMINANCE,
@@ -535,13 +541,15 @@ void ViewFinderGL::doRender()
glTexImage2D(GL_TEXTURE_2D,
0,
GL_LUMINANCE,
- size_.width() / horzSubSample_,
+ stride_ / horzSubSample_,
size_.height() / vertSubSample_,
0,
GL_LUMINANCE,
GL_UNSIGNED_BYTE,
image_->data(2).data());
shaderProgram_.setUniformValue(textureUniformV_, 2);
+
+ stridePixels = stride_;
break;
case libcamera::formats::YVU420:
@@ -551,7 +559,7 @@ void ViewFinderGL::doRender()
glTexImage2D(GL_TEXTURE_2D,
0,
GL_LUMINANCE,
- size_.width(),
+ stride_,
size_.height(),
0,
GL_LUMINANCE,
@@ -565,7 +573,7 @@ void ViewFinderGL::doRender()
glTexImage2D(GL_TEXTURE_2D,
0,
GL_LUMINANCE,
- size_.width() / horzSubSample_,
+ stride_ / horzSubSample_,
size_.height() / vertSubSample_,
0,
GL_LUMINANCE,
@@ -579,13 +587,15 @@ void ViewFinderGL::doRender()
glTexImage2D(GL_TEXTURE_2D,
0,
GL_LUMINANCE,
- size_.width() / horzSubSample_,
+ stride_ / horzSubSample_,
size_.height() / vertSubSample_,
0,
GL_LUMINANCE,
GL_UNSIGNED_BYTE,
image_->data(2).data());
shaderProgram_.setUniformValue(textureUniformU_, 1);
+
+ stridePixels = stride_;
break;
case libcamera::formats::UYVY:
@@ -602,7 +612,7 @@ void ViewFinderGL::doRender()
glTexImage2D(GL_TEXTURE_2D,
0,
GL_RGBA,
- size_.width() / 2,
+ stride_ / 4,
size_.height(),
0,
GL_RGBA,
@@ -619,6 +629,8 @@ void ViewFinderGL::doRender()
shaderProgram_.setUniformValue(textureUniformStep_,
1.0f / (size_.width() / 2 - 1),
1.0f /* not used */);
+
+ stridePixels = stride_ / 2;
break;
case libcamera::formats::ABGR8888:
@@ -630,13 +642,15 @@ void ViewFinderGL::doRender()
glTexImage2D(GL_TEXTURE_2D,
0,
GL_RGBA,
- size_.width(),
+ stride_ / 4,
size_.height(),
0,
GL_RGBA,
GL_UNSIGNED_BYTE,
image_->data(0).data());
shaderProgram_.setUniformValue(textureUniformY_, 0);
+
+ stridePixels = stride_ / 4;
break;
case libcamera::formats::BGR888:
@@ -646,13 +660,15 @@ void ViewFinderGL::doRender()
glTexImage2D(GL_TEXTURE_2D,
0,
GL_RGB,
- size_.width(),
+ stride_ / 3,
size_.height(),
0,
GL_RGB,
GL_UNSIGNED_BYTE,
image_->data(0).data());
shaderProgram_.setUniformValue(textureUniformY_, 0);
+
+ stridePixels = stride_ / 3;
break;
case libcamera::formats::SBGGR8:
@@ -692,11 +708,27 @@ void ViewFinderGL::doRender()
shaderProgram_.setUniformValue(textureUniformStep_,
1.0f / (stride_ - 1),
1.0f / (size_.height() - 1));
+
+ /*
+ * The stride is already taken into account in the shaders, set
+ * the generic stride factor to 1.0.
+ */
+ stridePixels = size_.width();
break;
default:
+ stridePixels = size_.width();
break;
};
+
+ /*
+ * Compute the stride factor for the vertex shader, to map the
+ * horizontal texture coordinate range [0.0, 1.0] to the active portion
+ * of the image.
+ */
+ shaderProgram_.setUniformValue(textureUniformStrideFactor_,
+ static_cast<float>(size_.width() - 1) /
+ (stridePixels - 1));
}
void ViewFinderGL::paintGL()
diff --git a/src/qcam/viewfinder_gl.h b/src/qcam/viewfinder_gl.h
index 2b2b1e86..37b1ddd0 100644
--- a/src/qcam/viewfinder_gl.h
+++ b/src/qcam/viewfinder_gl.h
@@ -97,6 +97,7 @@ private:
/* Raw Bayer texture parameters */
GLuint textureUniformSize_;
+ GLuint textureUniformStrideFactor_;
GLuint textureUniformBayerFirstRed_;
QPointF firstRed_;