[apps] Create a curve view to draw curves from any expression

Change-Id: I6e1183a560042688c596e3aa2385ab3bf0dcda2c
This commit is contained in:
Émilie Feral
2016-12-06 09:41:43 +01:00
parent cb4eb743fb
commit eeb17625d1
5 changed files with 247 additions and 207 deletions

View File

@@ -7,6 +7,7 @@ include apps/calculation/Makefile
app_objs += $(addprefix apps/,\
apps_container.o\
constant.o\
curve_view.o\
expression_text_field_delegate.o\
float_parameter_controller.o\
main.o\

176
apps/curve_view.cpp Normal file
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@@ -0,0 +1,176 @@
#include "curve_view.h"
#include "constant.h"
#include <assert.h>
#include <math.h>
#include <float.h>
constexpr KDColor CurveView::k_axisColor;
CurveView::CurveView() :
View()
{
}
void CurveView::reload() {
markRectAsDirty(bounds());
}
KDCoordinate CurveView::pixelLength(Axis axis) const {
assert(axis == Axis::Horizontal || axis == Axis::Vertical);
return (axis == Axis::Horizontal ? m_frame.width() : m_frame.height());
}
float CurveView::pixelToFloat(Axis axis, KDCoordinate p) const {
KDCoordinate pixels = axis == Axis::Horizontal ? p : pixelLength(axis)-p;
return min(axis) + pixels*(max(axis)-min(axis))/pixelLength(axis);
}
float CurveView::floatToPixel(Axis axis, float f) const {
float fraction = (f-min(axis))/(max(axis)-min(axis));
fraction = axis == Axis::Horizontal ? fraction : 1.0f - fraction;
return pixelLength(axis)*fraction;
}
void CurveView::drawLine(KDContext * ctx, KDRect rect, Axis axis, float coordinate, KDColor color, KDCoordinate thickness) const {
KDRect lineRect = KDRectZero;
switch(axis) {
// WARNING TODO: anti-aliasing?
case Axis::Horizontal:
lineRect = KDRect(
rect.x(), floatToPixel(Axis::Vertical, coordinate),
rect.width(), thickness
);
break;
case Axis::Vertical:
lineRect = KDRect(
floatToPixel(Axis::Horizontal, coordinate), rect.y(),
thickness, rect.height()
);
break;
}
ctx->fillRect(lineRect, color);
}
void CurveView::drawAxes(Axis axis, KDContext * ctx, KDRect rect) const {
drawLine(ctx, rect, axis, 0.0f, k_axisColor, 2);
}
#define LINE_THICKNESS 3
#if LINE_THICKNESS == 3
constexpr KDCoordinate circleDiameter = 3;
constexpr KDCoordinate stampSize = circleDiameter+1;
const uint8_t stampMask[stampSize+1][stampSize+1] = {
{0xFF, 0xFF, 0xFF, 0xFF, 0xFF},
{0xFF, 0x7A, 0x0C, 0x7A, 0xFF},
{0xFF, 0x0C, 0x00, 0x0C, 0xFF},
{0xFF, 0x7A, 0x0C, 0x7A, 0xFF},
{0xFF, 0xFF, 0xFF, 0xFF, 0xFF}
};
#elif LINE_THICKNESS == 5
constexpr KDCoordinate circleDiameter = 5;
constexpr KDCoordinate stampSize = circleDiameter+1;
const uint8_t stampMask[stampSize+1][stampSize+1] = {
{0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF},
{0xFF, 0xE1, 0x45, 0x0C, 0x45, 0xE1, 0xFF},
{0xFF, 0x45, 0x00, 0x00, 0x00, 0x45, 0xFF},
{0xFF, 0x0C, 0x00, 0x00, 0x00, 0x0C, 0xFF},
{0xFF, 0x45, 0x00, 0x00, 0x00, 0x45, 0xFF},
{0xFF, 0xE1, 0x45, 0x0C, 0x45, 0xE1, 0xFF},
{0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF},
};
#endif
constexpr static int k_maxNumberOfIterations = 10;
void CurveView::drawExpression(Expression * expression, KDColor color, KDContext * ctx, KDRect rect) const {
float xMin = min(Axis::Horizontal);
float xMax = max(Axis::Horizontal);
float xStep = (xMax-xMin)/320.0f;
for (float x = xMin; x < xMax; x += xStep) {
float y = evaluateExpressionAtAbscissa(expression, x);
float pxf = floatToPixel(Axis::Horizontal, x);
float pyf = floatToPixel(Axis::Vertical, y);
stampAtLocation(pxf, pyf, color, ctx);
if (x > xMin) {
jointDots(expression, x - xStep, evaluateExpressionAtAbscissa(expression, x-xStep), x, y, color, k_maxNumberOfIterations, ctx);
}
}
}
void CurveView::stampAtLocation(float pxf, float pyf, KDColor color, KDContext * ctx) const {
// We avoid drawing when no part of the stamp is visible
if (pyf < -stampSize || pyf > pixelLength(Axis::Vertical)+stampSize) {
return;
}
uint8_t shiftedMask[stampSize][stampSize];
KDColor workingBuffer[stampSize*stampSize];
KDCoordinate px = pxf;
KDCoordinate py = pyf;
float dx = pxf - floorf(pxf);
float dy = pyf - floorf(pyf);
/* TODO: this could be optimized by precomputing 10 or 100 shifted masks. The
* dx and dy would be rounded to one tenth or one hundredth to choose the
* right shifted mask. */
for (int i=0; i<stampSize; i++) {
for (int j=0; j<stampSize; j++) {
shiftedMask[i][j] = dx * (stampMask[i][j]*dy+stampMask[i+1][j]*(1.0f-dy))
+ (1.0f-dx) * (stampMask[i][j+1]*dy + stampMask[i+1][j+1]*(1.0f-dy));
}
}
KDRect stampRect(px-circleDiameter/2, py-circleDiameter/2, stampSize, stampSize);
ctx->blendRectWithMask(stampRect, color, (const uint8_t *)shiftedMask, workingBuffer);
}
void CurveView::jointDots(Expression * expression, float x, float y, float u, float v, KDColor color, int maxNumberOfRecursion, KDContext * ctx) const {
float pyf = floatToPixel(Axis::Vertical, y);
float pvf = floatToPixel(Axis::Vertical, v);
// No need to draw if both dots are outside visible area
if ((pyf < -stampSize && pvf < -stampSize) || (pyf > pixelLength(Axis::Vertical)+stampSize && pvf > pixelLength(Axis::Vertical)+stampSize)) {
return;
}
// If one of the dot is infinite, we cap it with a dot outside area
if (isinf(pyf)) {
pyf = pyf > 0 ? pixelLength(Axis::Vertical)+stampSize : -stampSize;
}
if (isinf(pvf)) {
pvf = pvf > 0 ? pixelLength(Axis::Vertical)+stampSize : -stampSize;
}
if (pyf - (float)circleDiameter/2.0f < pvf && pvf < pyf + (float)circleDiameter/2.0f) {
// the dots are already joined
return;
}
// C is the dot whose abscissa is between x and u
float cx = (x + u)/2.0f;
float cy = evaluateExpressionAtAbscissa(expression, cx);
if ((y < cy && cy < v) || (v < cy && cy < y)) {
/* As the middle dot is vertically between the two dots, we assume that we
* can draw a 'straight' line between the two */
float pxf = floatToPixel(Axis::Horizontal, x);
float puf = floatToPixel(Axis::Horizontal, u);
straightJoinDots(pxf, pyf, puf, pvf, color, ctx);
return;
}
float pcxf = floatToPixel(Axis::Horizontal, cx);
float pcyf = floatToPixel(Axis::Vertical, cy);
if (maxNumberOfRecursion > 0) {
stampAtLocation(pcxf, pcyf, color, ctx);
jointDots(expression, x, y, cx, cy, color, maxNumberOfRecursion-1, ctx);
jointDots(expression, cx, cy, u, v, color, maxNumberOfRecursion-1, ctx);
}
}
void CurveView::straightJoinDots(float pxf, float pyf, float puf, float pvf, KDColor color, KDContext * ctx) const {
if (pyf < pvf) {
for (float pnf = pyf; pnf<pvf; pnf+= 1.0f) {
float pmf = pxf + (pnf - pyf)*(puf - pxf)/(pvf - pyf);
stampAtLocation(pmf, pnf, color, ctx);
}
return;
}
straightJoinDots(puf, pvf, pxf, pyf, color, ctx);
}

39
apps/curve_view.h Normal file
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@@ -0,0 +1,39 @@
#ifndef APPS_CURVE_VIEW_H
#define APPS_CURVE_VIEW_H
#include <escher.h>
#include <poincare.h>
class CurveView : public View {
public:
CurveView();
void reload();
protected:
enum class Axis {
Horizontal = 0,
Vertical = 1
};
constexpr static KDColor k_axisColor = KDColor::RGB24(0x000000);
virtual float min(Axis axis) const = 0;
virtual float max(Axis axis) const = 0;
KDCoordinate pixelLength(Axis axis) const;
float pixelToFloat(Axis axis, KDCoordinate p) const;
float floatToPixel(Axis axis, float f) const;
void drawLine(KDContext * ctx, KDRect rect, Axis axis,
float coordinate, KDColor color, KDCoordinate thickness = 1) const;
void drawAxes(Axis axis, KDContext * ctx, KDRect rect) const;
void drawExpression(Expression * expression, KDColor color, KDContext * ctx, KDRect rect) const;
private:
virtual float evaluateExpressionAtAbscissa(Expression * expression, float abscissa) const = 0;
/* Recursively join two dots (dichotomy). The method stops when the
* maxNumberOfRecursion in reached. */
void jointDots(Expression * expression, float x, float y, float u, float v, KDColor color, int maxNumberOfRecursion, KDContext * ctx) const;
/* Join two dots with a straight line. */
void straightJoinDots(float pxf, float pyf, float puf, float pvf, KDColor color, KDContext * ctx) const;
/* Stamp centered around (pxf, pyf). If pxf and pyf are not round number, the
* function shifts the stamp (by blending adjacent pixel colors) to draw with
* anti alising. */
void stampAtLocation(float pxf, float pyf, KDColor color, KDContext * ctx) const;
};
#endif

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@@ -6,11 +6,10 @@
namespace Graph {
constexpr KDColor GraphView::k_axisColor;
constexpr KDColor GraphView::k_gridColor;
GraphView::GraphView(FunctionStore * functionStore, AxisInterval * axisInterval) :
View(),
CurveView(),
m_cursorView(CursorView()),
m_xCursorPosition(-1.0f),
m_yCursorPosition(-1.0f),
@@ -233,33 +232,12 @@ void GraphView::layoutSubviews() {
void GraphView::drawRect(KDContext * ctx, KDRect rect) const {
ctx->fillRect(rect, KDColorWhite);
drawGrid(ctx, rect);
drawAxes(ctx, rect);
drawFunction(ctx, rect);
}
void GraphView::drawLine(KDContext * ctx, KDRect rect, Axis axis, float coordinate, KDColor color, KDCoordinate thickness) const {
KDRect lineRect = KDRectZero;
switch(axis) {
// WARNING TODO: anti-aliasing?
case Axis::Horizontal:
lineRect = KDRect(
rect.x(), floatToPixel(Axis::Vertical, coordinate),
rect.width(), thickness
);
break;
case Axis::Vertical:
lineRect = KDRect(
floatToPixel(Axis::Horizontal, coordinate), rect.y(),
thickness, rect.height()
);
break;
drawAxes(Axis::Horizontal, ctx, rect);
drawAxes(Axis::Vertical, ctx, rect);
for (int i = 0; i < m_functionStore->numberOfActiveFunctions(); i++) {
Function * f = m_functionStore->activeFunctionAtIndex(i);
drawExpression(f->expression(), f->color(), ctx, rect);
}
ctx->fillRect(lineRect, color);
}
void GraphView::drawAxes(KDContext * ctx, KDRect rect) const {
drawLine(ctx, rect, Axis::Horizontal, 0.0f, k_axisColor, 2);
drawLine(ctx, rect, Axis::Vertical, 0.0f, k_axisColor, 2);
}
void GraphView::drawGridLines(KDContext * ctx, KDRect rect, Axis axis, float step, KDColor color) const {
@@ -285,143 +263,9 @@ float GraphView::max(Axis axis) const {
return (axis == Axis::Horizontal ? m_axisInterval->xMax() : m_axisInterval->yMax());
}
KDCoordinate GraphView::pixelLength(Axis axis) const {
assert(axis == Axis::Horizontal || axis == Axis::Vertical);
return (axis == Axis::Horizontal ? m_frame.width() : m_frame.height());
}
float GraphView::pixelToFloat(Axis axis, KDCoordinate p) const {
KDCoordinate pixels = axis == Axis::Horizontal ? p : pixelLength(axis)-p;
return min(axis) + pixels*(max(axis)-min(axis))/pixelLength(axis);
}
float GraphView::floatToPixel(Axis axis, float f) const {
float fraction = (f-min(axis))/(max(axis)-min(axis));
fraction = axis == Axis::Horizontal ? fraction : 1.0f - fraction;
return pixelLength(axis)*fraction;
}
#define LINE_THICKNESS 3
#if LINE_THICKNESS == 3
constexpr KDCoordinate circleDiameter = 3;
constexpr KDCoordinate stampSize = circleDiameter+1;
const uint8_t stampMask[stampSize+1][stampSize+1] = {
{0xFF, 0xFF, 0xFF, 0xFF, 0xFF},
{0xFF, 0x7A, 0x0C, 0x7A, 0xFF},
{0xFF, 0x0C, 0x00, 0x0C, 0xFF},
{0xFF, 0x7A, 0x0C, 0x7A, 0xFF},
{0xFF, 0xFF, 0xFF, 0xFF, 0xFF}
};
#elif LINE_THICKNESS == 5
constexpr KDCoordinate circleDiameter = 5;
constexpr KDCoordinate stampSize = circleDiameter+1;
const uint8_t stampMask[stampSize+1][stampSize+1] = {
{0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF},
{0xFF, 0xE1, 0x45, 0x0C, 0x45, 0xE1, 0xFF},
{0xFF, 0x45, 0x00, 0x00, 0x00, 0x45, 0xFF},
{0xFF, 0x0C, 0x00, 0x00, 0x00, 0x0C, 0xFF},
{0xFF, 0x45, 0x00, 0x00, 0x00, 0x45, 0xFF},
{0xFF, 0xE1, 0x45, 0x0C, 0x45, 0xE1, 0xFF},
{0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF},
};
#endif
constexpr static int k_maxNumberOfIterations = 10;
void GraphView::drawFunction(KDContext * ctx, KDRect rect) const {
float xMin = m_axisInterval->xMin();
float xMax = m_axisInterval->xMax();
float xStep = (xMax-xMin)/320.0f;
for (int i = 0; i < m_functionStore->numberOfActiveFunctions(); i++) {
Function * f = m_functionStore->activeFunctionAtIndex(i);
for (float x = xMin; x < xMax; x += xStep) {
float y = f->evaluateAtAbscissa(x, m_evaluateContext);
float pxf = floatToPixel(Axis::Horizontal, x);
float pyf = floatToPixel(Axis::Vertical, y);
stampAtLocation(pxf, pyf, f->color(), ctx);
if (x > xMin) {
jointDots(x - xStep, f->evaluateAtAbscissa(x-xStep, m_evaluateContext), x, y, f, k_maxNumberOfIterations, ctx);
}
}
}
}
void GraphView::stampAtLocation(float pxf, float pyf, KDColor color, KDContext * ctx) const {
// We avoid drawing when no part of the stamp is visible
if (pyf < -stampSize || pyf > pixelLength(Axis::Vertical)+stampSize) {
return;
}
uint8_t shiftedMask[stampSize][stampSize];
KDColor workingBuffer[stampSize*stampSize];
KDCoordinate px = pxf;
KDCoordinate py = pyf;
float dx = pxf - floorf(pxf);
float dy = pyf - floorf(pyf);
/* TODO: this could be optimized by precomputing 10 or 100 shifted masks. The
* dx and dy would be rounded to one tenth or one hundredth to choose the
* right shifted mask. */
for (int i=0; i<stampSize; i++) {
for (int j=0; j<stampSize; j++) {
shiftedMask[i][j] = dx * (stampMask[i][j]*dy+stampMask[i+1][j]*(1.0f-dy))
+ (1.0f-dx) * (stampMask[i][j+1]*dy + stampMask[i+1][j+1]*(1.0f-dy));
}
}
KDRect stampRect(px-circleDiameter/2, py-circleDiameter/2, stampSize, stampSize);
ctx->blendRectWithMask(stampRect, color, (const uint8_t *)shiftedMask, workingBuffer);
}
void GraphView::jointDots(float x, float y, float u, float v, Function * function, int maxNumberOfRecursion, KDContext * ctx) const {
float pyf = floatToPixel(Axis::Vertical, y);
float pvf = floatToPixel(Axis::Vertical, v);
// No need to draw if both dots are outside visible area
if ((pyf < -stampSize && pvf < -stampSize) || (pyf > pixelLength(Axis::Vertical)+stampSize && pvf > pixelLength(Axis::Vertical)+stampSize)) {
return;
}
// If one of the dot is infinite, we cap it with a dot outside area
if (isinf(pyf)) {
pyf = pyf > 0 ? pixelLength(Axis::Vertical)+stampSize : -stampSize;
}
if (isinf(pvf)) {
pvf = pvf > 0 ? pixelLength(Axis::Vertical)+stampSize : -stampSize;
}
if (pyf - (float)circleDiameter/2.0f < pvf && pvf < pyf + (float)circleDiameter/2.0f) {
// the dots are already joined
return;
}
// C is the dot whose abscissa is between x and u
float cx = (x + u)/2.0f;
float cy = function->evaluateAtAbscissa(cx, m_evaluateContext);
if ((y < cy && cy < v) || (v < cy && cy < y)) {
/* As the middle dot is vertically between the two dots, we assume that we
* can draw a 'straight' line between the two */
float pxf = floatToPixel(Axis::Horizontal, x);
float puf = floatToPixel(Axis::Horizontal, u);
straightJoinDots(pxf, pyf, puf, pvf, function->color(), ctx);
return;
}
float pcxf = floatToPixel(Axis::Horizontal, cx);
float pcyf = floatToPixel(Axis::Vertical, cy);
if (maxNumberOfRecursion > 0) {
stampAtLocation(pcxf, pcyf, function->color(), ctx);
jointDots(x, y, cx, cy, function, maxNumberOfRecursion-1, ctx);
jointDots(cx, cy, u, v, function, maxNumberOfRecursion-1, ctx);
}
}
void GraphView::straightJoinDots(float pxf, float pyf, float puf, float pvf, KDColor color, KDContext * ctx) const {
if (pyf < pvf) {
for (float pnf = pyf; pnf<pvf; pnf+= 1.0f) {
float pmf = pxf + (pnf - pyf)*(puf - pxf)/(pvf - pyf);
stampAtLocation(pmf, pnf, color, ctx);
}
return;
}
straightJoinDots(puf, pvf, pxf, pyf, color, ctx);
float GraphView::evaluateExpressionAtAbscissa(Expression * expression, float abscissa) const {
m_evaluateContext->setOverridenValueForSymbolX(abscissa);
return expression->approximate(*m_evaluateContext);
}
}

View File

@@ -4,12 +4,13 @@
#include <escher.h>
#include "cursor_view.h"
#include "axis_interval.h"
#include "../../curve_view.h"
#include "../function_store.h"
#include "../evaluate_context.h"
namespace Graph {
class GraphView : public View {
class GraphView : public CurveView {
public:
GraphView(FunctionStore * functionStore, AxisInterval * axisInterval);
void drawRect(KDContext * ctx, KDRect rect) const override;
@@ -27,47 +28,7 @@ public:
int indexFunctionSelectedByCursor();
void reload();
private:
constexpr static KDColor k_axisColor = KDColor::RGB24(0x000000);
constexpr static KDColor k_gridColor = KDColor::RGB24(0xEEEEEE);
int numberOfSubviews() const override;
View * subviewAtIndex(int index) override;
void layoutSubviews() override;
enum class Axis {
Horizontal = 0,
Vertical = 1
};
float min(Axis axis) const;
float max(Axis axis) const;
KDCoordinate pixelLength(Axis axis) const;
float pixelToFloat(Axis axis, KDCoordinate p) const;
float floatToPixel(Axis axis, float f) const;
void drawLine(KDContext * ctx, KDRect rect, Axis axis,
float coordinate, KDColor color, KDCoordinate thickness = 1) const;
void drawAxes(KDContext * ctx, KDRect rect) const;
void drawGrid(KDContext * ctx, KDRect rect) const;
void drawGridLines(KDContext * ctx, KDRect rect, Axis axis, float step, KDColor color) const;
void drawFunction(KDContext * ctx, KDRect rect) const;
/* Recursively join two dots (dichotomy). The method stops when the
* maxNumberOfRecursion in reached. */
void jointDots(float x, float y, float u, float v, Function * function, int maxNumberOfRecursion, KDContext * ctx) const;
/* Join two dots with a straight line. */
void straightJoinDots(float pxf, float pyf, float puf, float pvf, KDColor color, KDContext * ctx) const;
/* Stamp centered around (pxf, pyf). If pxf and pyf are not round number, the
* function shifts the stamp (by blending adjacent pixel colors) to draw with
* anti alising. */
void stampAtLocation(float pxf, float pyf, KDColor color, KDContext * ctx) const;
int numberOfXLabels() const;
int numberOfYLabels() const;
CursorView m_cursorView;
float m_xCursorPosition;
float m_yCursorPosition;
int m_indexFunctionSelectedByCursor;
bool m_visibleCursor;
constexpr static KDCoordinate k_cursorSize = 10;
constexpr static float k_cursorMarginToBorder = 5.0f;
constexpr static KDCoordinate k_labelWidth = 32;
@@ -75,11 +36,30 @@ private:
constexpr static KDCoordinate k_labelMargin = 4;
constexpr static int k_maxNumberOfXLabels = 18;
constexpr static int k_maxNumberOfYLabels = 13;
int numberOfSubviews() const override;
View * subviewAtIndex(int index) override;
void layoutSubviews() override;
float min(Axis axis) const override;
float max(Axis axis) const override;
float evaluateExpressionAtAbscissa(Expression * expression, float abscissa) const override;
void drawGrid(KDContext * ctx, KDRect rect) const;
void drawGridLines(KDContext * ctx, KDRect rect, Axis axis, float step, KDColor color) const;
int numberOfXLabels() const;
int numberOfYLabels() const;
CursorView m_cursorView;
float m_xCursorPosition;
float m_yCursorPosition;
int m_indexFunctionSelectedByCursor;
bool m_visibleCursor;
BufferTextView m_xLabels[k_maxNumberOfXLabels];
BufferTextView m_yLabels[k_maxNumberOfYLabels];
AxisInterval * m_axisInterval;
FunctionStore * m_functionStore;
EvaluateContext * m_evaluateContext;
};