Files
Upsilon/apps/graph/graph/graph_view.cpp
Romain Goyet 1cdb7cac9d Graph: Secondary grid
Change-Id: Ie4c38ce7b0db3c31d85300a89619883b1bf5109e
2016-06-21 14:06:01 +02:00

123 lines
3.5 KiB
C++

#include "graph_view.h"
#include <assert.h>
constexpr KDColor kAxisColor = KDColorGray(0x0);
constexpr KDColor kMainGridColor = KDColorGray(0xCC);
constexpr KDColor kSecondaryGridColor = KDColorGray(0xEE);
constexpr int kNumberOfMainGridLines = 5;
constexpr int kNumberOfSecondaryGridLines = 4;
GraphView::GraphView() :
View(),
m_cursorView(CursorView()),
m_cursorPosition(KDPointZero),
m_xMin(-2.0f),
m_xMax(2.0f),
m_yMin(-2.0f),
m_yMax(2.0f)
{
}
int GraphView::numberOfSubviews() const {
return 1;
};
View * GraphView::subviewAtIndex(int index) {
return &m_cursorView;
}
void GraphView::moveCursorRight() {
m_cursorPosition.x = m_cursorPosition.x + 2;
layoutSubviews();
}
void GraphView::layoutSubviews() {
KDRect cursorFrame;
cursorFrame.origin = m_cursorPosition;
cursorFrame.width = 10;
cursorFrame.height = 10;
m_cursorView.setFrame(cursorFrame);
}
void GraphView::drawRect(KDRect rect) const {
KDFillRect(rect, KDColorWhite);
drawGrid(rect);
drawAxes(rect);
drawFunction(rect);
}
void GraphView::drawLine(KDRect rect, Axis axis, float coordinate, KDColor color) const {
KDRect lineRect;
switch(axis) {
case Axis::Horizontal:
lineRect.x = rect.x;
lineRect.y = floatToPixel(Axis::Vertical, coordinate);
lineRect.width = rect.width;
lineRect.height = 1;
break;
case Axis::Vertical:
lineRect.x = floatToPixel(Axis::Horizontal, coordinate);
lineRect.y = rect.y;
lineRect.width = 1;
lineRect.height = rect.height;
break;
}
KDFillRect(lineRect, color);
}
void GraphView::drawAxes(KDRect rect) const {
drawLine(rect, Axis::Horizontal, 0.0f, kAxisColor);
drawLine(rect, Axis::Vertical, 0.0f, kAxisColor);
}
void GraphView::drawGridLines(KDRect rect, Axis axis, int count, KDColor color) const {
float range = max(axis)-min(axis);
float step = range/count;
float start = step*((int)(min(axis)/step));
for (int i=0; i<count; i++) {
Axis otherAxis = (axis == Axis::Horizontal) ? Axis::Vertical : Axis::Horizontal;
drawLine(rect, otherAxis, start+i*step, color);
}
}
void GraphView::drawGrid(KDRect rect) const {
drawGridLines(rect, Axis::Horizontal, kNumberOfMainGridLines*kNumberOfSecondaryGridLines, kSecondaryGridColor);
drawGridLines(rect, Axis::Vertical, kNumberOfMainGridLines*kNumberOfSecondaryGridLines, kSecondaryGridColor);
drawGridLines(rect, Axis::Horizontal, kNumberOfMainGridLines, kMainGridColor);
drawGridLines(rect, Axis::Vertical, kNumberOfMainGridLines, kMainGridColor);
}
float GraphView::min(Axis axis) const {
assert(axis == Axis::Horizontal || axis == Axis::Vertical);
return (axis == Axis::Horizontal ? m_xMin : m_yMin);
}
float GraphView::max(Axis axis) const {
assert(axis == Axis::Horizontal || axis == Axis::Vertical);
return (axis == Axis::Horizontal ? m_xMax : m_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 {
return min(axis) + p*(max(axis)-min(axis))/pixelLength(axis);
}
KDCoordinate GraphView::floatToPixel(Axis axis, float f) const {
return pixelLength(axis)*(max(axis)-f)/(max(axis)-min(axis));
}
void GraphView::drawFunction(KDRect rect) const {
KDPoint p = KDPointZero;
for (p.x=rect.x; p.x<(rect.x+rect.width); p.x++) {
float x = pixelToFloat(Axis::Horizontal, p.x);
float y = (x-1)*(x+1)*x;
p.y = floatToPixel(Axis::Vertical, y);
KDSetPixel(p, KDColorRGB(0xCF, 0, 0));
}
}