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JUCE/modules/juce_opengl/opengl/juce_OpenGLHelpers.cpp
2011-10-08 19:04:43 +01:00

265 lines
10 KiB
C++

/*
==============================================================================
This file is part of the JUCE library - "Jules' Utility Class Extensions"
Copyright 2004-11 by Raw Material Software Ltd.
------------------------------------------------------------------------------
JUCE can be redistributed and/or modified under the terms of the GNU General
Public License (Version 2), as published by the Free Software Foundation.
A copy of the license is included in the JUCE distribution, or can be found
online at www.gnu.org/licenses.
JUCE is distributed in the hope that it will be useful, but WITHOUT ANY
WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
A PARTICULAR PURPOSE. See the GNU General Public License for more details.
------------------------------------------------------------------------------
To release a closed-source product which uses JUCE, commercial licenses are
available: visit www.rawmaterialsoftware.com/juce for more information.
==============================================================================
*/
BEGIN_JUCE_NAMESPACE
void OpenGLHelpers::resetErrorState()
{
while (glGetError() != GL_NO_ERROR) {}
}
void OpenGLHelpers::clear (const Colour& colour)
{
glClearColor (colour.getFloatRed(), colour.getFloatGreen(),
colour.getFloatBlue(), colour.getFloatAlpha());
glClear (GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT | GL_STENCIL_BUFFER_BIT);
}
void OpenGLHelpers::setColour (const Colour& colour)
{
glColor4f (colour.getFloatRed(), colour.getFloatGreen(),
colour.getFloatBlue(), colour.getFloatAlpha());
}
void OpenGLHelpers::prepareFor2D (int width, int height)
{
glMatrixMode (GL_PROJECTION);
glLoadIdentity();
#if JUCE_OPENGL_ES
glOrthof (0.0f, (float) width, 0.0f, (float) height, 0.0f, 1.0f);
#else
glOrtho (0.0, width, 0.0, height, 0, 1);
#endif
glViewport (0, 0, width, height);
}
void OpenGLHelpers::setPerspective (double fovy, double aspect, double zNear, double zFar)
{
glLoadIdentity();
#if JUCE_OPENGL_ES
const float ymax = (float) (zNear * tan (fovy * double_Pi / 360.0));
const float ymin = -ymax;
glFrustumf (ymin * (float) aspect, ymax * (float) aspect, ymin, ymax, (float) zNear, (float) zFar);
#else
const double ymax = zNear * tan (fovy * double_Pi / 360.0);
const double ymin = -ymax;
glFrustum (ymin * aspect, ymax * aspect, ymin, ymax, zNear, zFar);
#endif
}
void OpenGLHelpers::drawQuad2D (float x1, float y1,
float x2, float y2,
float x3, float y3,
float x4, float y4,
const Colour& colour)
{
const GLfloat vertices[] = { x1, y1, x2, y2, x4, y4, x3, y3 };
const GLfloat textureCoords[] = { 0, 0, 1.0f, 0, 0, 1.0f, 1.0f, 1.0f };
setColour (colour);
glEnableClientState (GL_VERTEX_ARRAY);
glVertexPointer (2, GL_FLOAT, 0, vertices);
glEnableClientState (GL_TEXTURE_COORD_ARRAY);
glTexCoordPointer (2, GL_FLOAT, 0, textureCoords);
glDisableClientState (GL_COLOR_ARRAY);
glDisableClientState (GL_NORMAL_ARRAY);
glDrawArrays (GL_TRIANGLE_STRIP, 0, 4);
}
void OpenGLHelpers::drawQuad3D (float x1, float y1, float z1,
float x2, float y2, float z2,
float x3, float y3, float z3,
float x4, float y4, float z4,
const Colour& colour)
{
const GLfloat vertices[] = { x1, y1, z1, x2, y2, z2, x4, y4, z4, x3, y3, z3 };
const GLfloat textureCoords[] = { 0, 0, 1.0f, 0, 0, 1.0f, 1.0f, 1.0f };
setColour (colour);
glEnableClientState (GL_VERTEX_ARRAY);
glVertexPointer (3, GL_FLOAT, 0, vertices);
glEnableClientState (GL_TEXTURE_COORD_ARRAY);
glTexCoordPointer (2, GL_FLOAT, 0, textureCoords);
glDisableClientState (GL_COLOR_ARRAY);
glDisableClientState (GL_NORMAL_ARRAY);
glDrawArrays (GL_TRIANGLE_STRIP, 0, 4);
}
namespace OpenGLGradientHelpers
{
void drawTriangles (GLenum mode, const GLfloat* vertices, const GLfloat* textureCoords, const int numElements)
{
glEnableClientState (GL_VERTEX_ARRAY);
glEnableClientState (GL_TEXTURE_COORD_ARRAY);
glDisableClientState (GL_COLOR_ARRAY);
glDisableClientState (GL_NORMAL_ARRAY);
glVertexPointer (2, GL_FLOAT, 0, vertices);
glTexCoordPointer (2, GL_FLOAT, 0, textureCoords);
glColor4f (1.0f, 1.0f, 1.0f, 1.0f);
glDrawArrays (mode, 0, numElements);
}
void fillWithLinearGradient (const Rectangle<int>& rect,
const ColourGradient& grad,
const AffineTransform& transform,
const int textureSize)
{
const Point<float> p1 (grad.point1.transformedBy (transform));
const Point<float> p2 (grad.point2.transformedBy (transform));
const Point<float> p3 (Point<float> (grad.point1.getX() - (grad.point2.getY() - grad.point1.getY()) / textureSize,
grad.point1.getY() + (grad.point2.getX() - grad.point1.getX()) / textureSize).transformedBy (transform));
const AffineTransform textureTransform (AffineTransform::fromTargetPoints (p1.getX(), p1.getY(), 0.0f, 0.0f,
p2.getX(), p2.getY(), 1.0f, 0.0f,
p3.getX(), p3.getY(), 0.0f, 1.0f));
const float l = (float) rect.getX();
const float r = (float) rect.getRight();
const float t = (float) rect.getY();
const float b = (float) rect.getBottom();
const GLfloat vertices[] = { l, t, r, t, l, b, r, b };
GLfloat textureCoords[] = { l, t, r, t, l, b, r, b };
textureTransform.transformPoints (textureCoords[0], textureCoords[1], textureCoords[2], textureCoords[3]);
textureTransform.transformPoints (textureCoords[4], textureCoords[5], textureCoords[6], textureCoords[7]);
drawTriangles (GL_TRIANGLE_STRIP, vertices, textureCoords, 4);
}
void fillWithRadialGradient (const Rectangle<int>& rect,
const ColourGradient& grad,
const AffineTransform& transform)
{
const Point<float> centre (grad.point1.transformedBy (transform));
const float screenRadius = centre.getDistanceFrom (rect.getCentre().toFloat())
+ Point<int> (rect.getWidth() / 2,
rect.getHeight() / 2).getDistanceFromOrigin()
+ 8.0f;
const AffineTransform inverse (transform.inverted());
const float sourceRadius = jmax (Point<float> (screenRadius, 0.0f).transformedBy (inverse).getDistanceFromOrigin(),
Point<float> (0.0f, screenRadius).transformedBy (inverse).getDistanceFromOrigin());
const int numDivisions = 80;
GLfloat vertices [6 + numDivisions * 4];
GLfloat textureCoords [6 + numDivisions * 4];
{
const float originalRadius = grad.point1.getDistanceFrom (grad.point2);
const float texturePos = sourceRadius / originalRadius;
GLfloat* t = textureCoords;
*t++ = 0.0f;
*t++ = 0.0f;
for (int i = numDivisions + 1; --i >= 0;)
{
*t++ = texturePos;
*t++ = 0.0f;
*t++ = texturePos;
*t++ = 1.0f;
}
jassert (t == textureCoords + numElementsInArray (vertices));
}
{
GLfloat* v = vertices;
*v++ = centre.getX();
*v++ = centre.getY();
const Point<float> first (grad.point1.translated (sourceRadius, -sourceRadius).transformedBy (transform));
Point<float> last (first);
for (int i = 0; i < numDivisions; ++i)
{
const float angle = (i + 1) * (float_Pi * 4.0f / numDivisions);
const Point<float> next (grad.point1.translated (std::sin (angle) * sourceRadius,
std::cos (angle) * -sourceRadius)
.transformedBy (transform));
*v++ = last.getX();
*v++ = last.getY();
*v++ = next.getX();
*v++ = next.getY();
last = next;
}
*v++ = last.getX();
*v++ = last.getY();
*v++ = first.getX();
*v++ = first.getY();
jassert (v == vertices + numElementsInArray (vertices));
}
glEnable (GL_SCISSOR_TEST);
glScissor (rect.getX(), rect.getY(), rect.getWidth(), rect.getHeight());
drawTriangles (GL_TRIANGLE_FAN, vertices, textureCoords, numDivisions + 3);
glDisable (GL_SCISSOR_TEST);
}
}
void OpenGLHelpers::fillRectWithColourGradient (const Rectangle<int>& rect,
const ColourGradient& gradient,
const AffineTransform& transform)
{
const int textureSize = 256;
OpenGLTexture texture;
HeapBlock<PixelARGB> lookup (textureSize);
gradient.createLookupTable (lookup, textureSize);
texture.load (lookup, textureSize, 1);
texture.bind();
if (gradient.isOpaque())
glDisable (GL_BLEND);
else
glEnable (GL_BLEND);
if (gradient.isRadial)
OpenGLGradientHelpers::fillWithRadialGradient (rect, gradient, transform);
else
OpenGLGradientHelpers::fillWithLinearGradient (rect, gradient, transform, textureSize);
}
END_JUCE_NAMESPACE