// Copyright (c) 2013 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#ifndef CONTENT_BROWSER_COMPOSITOR_GL_HELPER_SCALING_H_
#define CONTENT_BROWSER_COMPOSITOR_GL_HELPER_SCALING_H_
#include <deque>
#include <map>
#include <vector>
#include "base/macros.h"
#include "content/browser/compositor/gl_helper.h"
#include "ui/gfx/geometry/rect.h"
#include "ui/gfx/geometry/size.h"
namespace content {
class ShaderProgram;
class ScalerImpl;
class GLHelperTest;
// Implements GPU texture scaling methods.
// Note that you should probably not use this class directly.
// See gl_helper.cc::CreateScaler instead.
class CONTENT_EXPORT GLHelperScaling {
public:
enum ShaderType {
SHADER_BILINEAR,
SHADER_BILINEAR2,
SHADER_BILINEAR3,
SHADER_BILINEAR4,
SHADER_BILINEAR2X2,
SHADER_BICUBIC_UPSCALE,
SHADER_BICUBIC_HALF_1D,
SHADER_PLANAR,
SHADER_YUV_MRT_PASS1,
SHADER_YUV_MRT_PASS2,
};
// Similar to ScalerInterface, but can generate multiple outputs.
// Used for YUV conversion in gl_helper.c
class CONTENT_EXPORT ShaderInterface {
public:
ShaderInterface() {}
virtual ~ShaderInterface() {}
// Note that the src_texture will have the min/mag filter set to GL_LINEAR
// and wrap_s/t set to CLAMP_TO_EDGE in this call.
virtual void Execute(GLuint source_texture,
const std::vector<GLuint>& dest_textures) = 0;
};
typedef std::pair<ShaderType, bool> ShaderProgramKeyType;
GLHelperScaling(gpu::gles2::GLES2Interface* gl, GLHelper* helper);
~GLHelperScaling();
void InitBuffer();
GLHelper::ScalerInterface* CreateScaler(GLHelper::ScalerQuality quality,
gfx::Size src_size,
gfx::Rect src_subrect,
const gfx::Size& dst_size,
bool vertically_flip_texture,
bool swizzle);
GLHelper::ScalerInterface* CreatePlanarScaler(const gfx::Size& src_size,
const gfx::Rect& src_subrect,
const gfx::Size& dst_size,
bool vertically_flip_texture,
bool swizzle,
const float color_weights[4]);
ShaderInterface* CreateYuvMrtShader(const gfx::Size& src_size,
const gfx::Rect& src_subrect,
const gfx::Size& dst_size,
bool vertically_flip_texture,
bool swizzle,
ShaderType shader);
private:
// A ScaleOp represents a pass in a scaler pipeline, in one dimension.
// Note that when quality is GOOD, multiple scaler passes will be
// combined into one operation for increased performance.
// Exposed in the header file for testing purposes.
struct ScaleOp {
ScaleOp(int factor, bool x, int size)
: scale_factor(factor), scale_x(x), scale_size(size) {}
// Calculate a set of ScaleOp needed to convert an image of size
// |src| into an image of size |dst|. If |scale_x| is true, then
// the calculations are for the X axis of the image, otherwise Y.
// If |allow3| is true, we can use a SHADER_BILINEAR3 to replace
// a scale up and scale down with a 3-tap bilinear scale.
// The calculated ScaleOps are added to |ops|.
static void AddOps(int src,
int dst,
bool scale_x,
bool allow3,
std::deque<ScaleOp>* ops) {
int num_downscales = 0;
if (allow3 && dst * 3 >= src && dst * 2 < src) {
// Technically, this should be a scale up and then a
// scale down, but it makes the optimization code more
// complicated.
ops->push_back(ScaleOp(3, scale_x, dst));
return;
}
while ((dst << num_downscales) < src) {
num_downscales++;
}
if ((dst << num_downscales) != src) {
ops->push_back(ScaleOp(0, scale_x, dst << num_downscales));
}
while (num_downscales) {
num_downscales--;
ops->push_back(ScaleOp(2, scale_x, dst << num_downscales));
}
}
// Update |size| to its new size. Before calling this function
// |size| should be the size of the input image. After calling it,
// |size| will be the size of the image after this particular
// scaling operation.
void UpdateSize(gfx::Size* subrect) {
if (scale_x) {
subrect->set_width(scale_size);
} else {
subrect->set_height(scale_size);
}
}
// A scale factor of 0 means upscale
// 2 means 50% scale
// 3 means 33% scale, etc.
int scale_factor;
bool scale_x; // Otherwise y
int scale_size; // Size to scale to.
};
// Full specification for a single scaling stage.
struct ScalerStage {
ScalerStage(ShaderType shader_,
gfx::Size src_size_,
gfx::Rect src_subrect_,
gfx::Size dst_size_,
bool scale_x_,
bool vertically_flip_texture_,
bool swizzle_);
ScalerStage(const ScalerStage& other);
ShaderType shader;
gfx::Size src_size;
gfx::Rect src_subrect;
gfx::Size dst_size;
bool scale_x;
bool vertically_flip_texture;
bool swizzle;
};
// Compute a vector of scaler stages for a particular
// set of input/output parameters.
void ComputeScalerStages(GLHelper::ScalerQuality quality,
const gfx::Size& src_size,
const gfx::Rect& src_subrect,
const gfx::Size& dst_size,
bool vertically_flip_texture,
bool swizzle,
std::vector<ScalerStage>* scaler_stages);
// Take two queues of ScaleOp structs and generate a
// vector of scaler stages. This is the second half of
// ComputeScalerStages.
void ConvertScalerOpsToScalerStages(
GLHelper::ScalerQuality quality,
gfx::Size src_size,
gfx::Rect src_subrect,
const gfx::Size& dst_size,
bool vertically_flip_texture,
bool swizzle,
std::deque<GLHelperScaling::ScaleOp>* x_ops,
std::deque<GLHelperScaling::ScaleOp>* y_ops,
std::vector<ScalerStage>* scaler_stages);
scoped_refptr<ShaderProgram> GetShaderProgram(ShaderType type, bool swizzle);
// Interleaved array of 2-dimentional vertex positions (x, y) and
// 2-dimentional texture coordinates (s, t).
static const GLfloat kVertexAttributes[];
gpu::gles2::GLES2Interface* gl_;
GLHelper* helper_;
// The buffer that holds the vertices and the texture coordinates data for
// drawing a quad.
ScopedBuffer vertex_attributes_buffer_;
std::map<ShaderProgramKeyType, scoped_refptr<ShaderProgram>> shader_programs_;
friend class ShaderProgram;
friend class ScalerImpl;
friend class GLHelperTest;
DISALLOW_COPY_AND_ASSIGN(GLHelperScaling);
};
} // namespace content
#endif // CONTENT_BROWSER_COMPOSITOR_GL_HELPER_SCALING_H_