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36107cb7e1
0ad/source/renderer/ShadowMap.cpp
Ykkrosh 36107cb7e1 GLES compatibility for particles and shadows. 
Fix invalid enum errors.
Fix shader texture binding.

This was SVN commit r11372.
2012-03-19 21:10:14 +00:00

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/* Copyright (C) 2012 Wildfire Games.
* This file is part of 0 A.D.
*
* 0 A.D. is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 2 of the License, or
* (at your option) any later version.
*
* 0 A.D. 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.
*
* You should have received a copy of the GNU General Public License
* along with 0 A.D. If not, see <http://www.gnu.org/licenses/>.
*/
/*
* Shadow mapping related texture and matrix management
*/
#include "precompiled.h"
#include "gui/GUIutil.h"
#include "lib/bits.h"
#include "lib/ogl.h"
#include "ps/CLogger.h"
#include "ps/Profile.h"
#include "graphics/LightEnv.h"
#include "graphics/ShaderManager.h"
#include "maths/BoundingBoxAligned.h"
#include "maths/MathUtil.h"
#include "maths/Matrix3D.h"
#include "renderer/Renderer.h"
#include "renderer/ShadowMap.h"
///////////////////////////////////////////////////////////////////////////////////////////////////
// ShadowMap implementation
/**
* Struct ShadowMapInternals: Internal data for the ShadowMap implementation
*/
struct ShadowMapInternals
{
// bit depth for the depth texture
int DepthTextureBits;
// the EXT_framebuffer_object framebuffer
GLuint Framebuffer;
// handle of shadow map
GLuint Texture;
// width, height of shadow map
int Width, Height;
// used width, height of shadow map
int EffectiveWidth, EffectiveHeight;
// transform light space into projected light space
// in projected light space, the shadowbound box occupies the [-1..1] cube
// calculated on BeginRender, after the final shadow bounds are known
CMatrix3D LightProjection;
// Transform world space into light space; calculated on SetupFrame
CMatrix3D LightTransform;
// Transform world space into texture space of the shadow map;
// calculated on BeginRender, after the final shadow bounds are known
CMatrix3D TextureMatrix;
// transform light space into world space
CMatrix3D InvLightTransform;
// bounding box of shadowed objects in light space
CBoundingBoxAligned ShadowBound;
// Camera transformed into light space
CCamera LightspaceCamera;
// Some drivers (at least some Intel Mesa ones) appear to handle alpha testing
// incorrectly when the FBO has only a depth attachment.
// When m_ShadowAlphaFix is true, we use DummyTexture to store a useless
// alpha texture which is attached to the FBO as a workaround.
GLuint DummyTexture;
// Copy of renderer's standard view camera, saved between
// BeginRender and EndRender while we replace it with the shadow camera
CCamera SavedViewCamera;
float FilterOffsets[8];
// Helper functions
void CalcShadowMatrices();
void CreateTexture();
};
///////////////////////////////////////////////////////////////////////////////////////////////////
// Construction/Destruction
ShadowMap::ShadowMap()
{
m = new ShadowMapInternals;
m->Framebuffer = 0;
m->Texture = 0;
m->DummyTexture = 0;
m->Width = 0;
m->Height = 0;
m->EffectiveWidth = 0;
m->EffectiveHeight = 0;
m->DepthTextureBits = 0;
// DepthTextureBits: 24/32 are very much faster than 16, on GeForce 4 and FX;
// but they're very much slower on Radeon 9800.
// In both cases, the default (no specified depth) is fast, so we just use
// that by default and hope it's alright. (Otherwise, we'd probably need to
// do some kind of hardware detection to work out what to use.)
// Avoid using uninitialised values in AddShadowedBound if SetupFrame wasn't called first
m->LightTransform.SetIdentity();
}
ShadowMap::~ShadowMap()
{
if (m->Texture)
glDeleteTextures(1, &m->Texture);
if (m->DummyTexture)
glDeleteTextures(1, &m->DummyTexture);
if (m->Framebuffer)
pglDeleteFramebuffersEXT(1, &m->Framebuffer);
delete m;
}
///////////////////////////////////////////////////////////////////////////////////////////////////
// Force the texture/buffer/etc to be recreated, particularly when the renderer's
// size has changed
void ShadowMap::RecreateTexture()
{
if (m->Texture)
glDeleteTextures(1, &m->Texture);
if (m->DummyTexture)
glDeleteTextures(1, &m->DummyTexture);
if (m->Framebuffer)
pglDeleteFramebuffersEXT(1, &m->Framebuffer);
m->Texture = 0;
m->DummyTexture = 0;
m->Framebuffer = 0;
// (Texture will be constructed in next SetupFrame)
}
//////////////////////////////////////////////////////////////////////////////
// SetupFrame: camera and light direction for this frame
void ShadowMap::SetupFrame(const CCamera& camera, const CVector3D& lightdir)
{
if (!m->Texture)
m->CreateTexture();
CVector3D z = lightdir;
CVector3D y;
CVector3D x = camera.m_Orientation.GetIn();
CVector3D eyepos = camera.m_Orientation.GetTranslation();
z.Normalize();
x -= z * z.Dot(x);
if (x.Length() < 0.001)
{
// this is invoked if the camera and light directions almost coincide
// assumption: light direction has a significant Z component
x = CVector3D(1.0, 0.0, 0.0);
x -= z * z.Dot(x);
}
x.Normalize();
y = z.Cross(x);
// X axis perpendicular to light direction, flowing along with view direction
m->LightTransform._11 = x.X;
m->LightTransform._12 = x.Y;
m->LightTransform._13 = x.Z;
// Y axis perpendicular to light and view direction
m->LightTransform._21 = y.X;
m->LightTransform._22 = y.Y;
m->LightTransform._23 = y.Z;
// Z axis is in direction of light
m->LightTransform._31 = z.X;
m->LightTransform._32 = z.Y;
m->LightTransform._33 = z.Z;
// eye is at the origin of the coordinate system
m->LightTransform._14 = -x.Dot(eyepos);
m->LightTransform._24 = -y.Dot(eyepos);
m->LightTransform._34 = -z.Dot(eyepos);
m->LightTransform._41 = 0.0;
m->LightTransform._42 = 0.0;
m->LightTransform._43 = 0.0;
m->LightTransform._44 = 1.0;
m->LightTransform.GetInverse(m->InvLightTransform);
m->ShadowBound.SetEmpty();
//
m->LightspaceCamera = camera;
m->LightspaceCamera.m_Orientation = m->LightTransform * camera.m_Orientation;
m->LightspaceCamera.UpdateFrustum();
}
//////////////////////////////////////////////////////////////////////////////
// AddShadowedBound: add a world-space bounding box to the bounds of shadowed
// objects
void ShadowMap::AddShadowedBound(const CBoundingBoxAligned& bounds)
{
CBoundingBoxAligned lightspacebounds;
bounds.Transform(m->LightTransform, lightspacebounds);
m->ShadowBound += lightspacebounds;
}
///////////////////////////////////////////////////////////////////////////////////////////////////
// CalcShadowMatrices: calculate required matrices for shadow map generation - the light's
// projection and transformation matrices
void ShadowMapInternals::CalcShadowMatrices()
{
CRenderer& renderer = g_Renderer;
float minZ = ShadowBound[0].Z;
ShadowBound.IntersectFrustumConservative(LightspaceCamera.GetFrustum());
// round off the shadow boundaries to sane increments to help reduce swim effect
float boundInc = 16.0f;
ShadowBound[0].X = floor(ShadowBound[0].X / boundInc) * boundInc;
ShadowBound[0].Y = floor(ShadowBound[0].Y / boundInc) * boundInc;
ShadowBound[1].X = ceil(ShadowBound[1].X / boundInc) * boundInc;
ShadowBound[1].Y = ceil(ShadowBound[1].Y / boundInc) * boundInc;
// minimum Z bound must not be clipped too much, because objects that lie outside
// the shadow bounds cannot cast shadows either
// the 2.0 is rather arbitrary: it should be big enough so that we won't accidentally miss
// a shadow generator, and small enough not to affect Z precision
ShadowBound[0].Z = minZ - 2.0;
// Setup orthogonal projection (lightspace -> clip space) for shadowmap rendering
CVector3D scale = ShadowBound[1] - ShadowBound[0];
CVector3D shift = (ShadowBound[1] + ShadowBound[0]) * -0.5;
if (scale.X < 1.0)
scale.X = 1.0;
if (scale.Y < 1.0)
scale.Y = 1.0;
if (scale.Z < 1.0)
scale.Z = 1.0;
scale.X = 2.0 / scale.X;
scale.Y = 2.0 / scale.Y;
scale.Z = 2.0 / scale.Z;
// make sure a given world position falls on a consistent shadowmap texel fractional offset
float offsetX = fmod(ShadowBound[0].X - LightTransform._14, 2.0f/(scale.X*EffectiveWidth));
float offsetY = fmod(ShadowBound[0].Y - LightTransform._24, 2.0f/(scale.Y*EffectiveHeight));
LightProjection.SetZero();
LightProjection._11 = scale.X;
LightProjection._14 = (shift.X + offsetX) * scale.X;
LightProjection._22 = scale.Y;
LightProjection._24 = (shift.Y + offsetY) * scale.Y;
LightProjection._33 = scale.Z;
LightProjection._34 = shift.Z * scale.Z + renderer.m_ShadowZBias;
LightProjection._44 = 1.0;
// Calculate texture matrix by creating the clip space to texture coordinate matrix
// and then concatenating all matrices that have been calculated so far
CMatrix3D lightToTex;
float texscalex = scale.X * 0.5f * (float)EffectiveWidth / (float)Width;
float texscaley = scale.Y * 0.5f * (float)EffectiveHeight / (float)Height;
float texscalez = scale.Z * 0.5f;
lightToTex.SetZero();
lightToTex._11 = texscalex;
lightToTex._14 = (offsetX - ShadowBound[0].X) * texscalex;
lightToTex._22 = texscaley;
lightToTex._24 = (offsetY - ShadowBound[0].Y) * texscaley;
lightToTex._33 = texscalez;
lightToTex._34 = -ShadowBound[0].Z * texscalez;
lightToTex._44 = 1.0;
TextureMatrix = lightToTex * LightTransform;
}
//////////////////////////////////////////////////////////////////////////
// Create the shadow map
void ShadowMapInternals::CreateTexture()
{
// Cleanup
if (Texture)
{
glDeleteTextures(1, &Texture);
Texture = 0;
}
if (DummyTexture)
{
glDeleteTextures(1, &DummyTexture);
DummyTexture = 0;
}
if (Framebuffer)
{
pglDeleteFramebuffersEXT(1, &Framebuffer);
Framebuffer = 0;
}
pglGenFramebuffersEXT(1, &Framebuffer);
if (g_Renderer.m_ShadowMapSize != 0)
{
// non-default option to override the size
Width = Height = g_Renderer.m_ShadowMapSize;
}
else
{
// get shadow map size as next power of two up from view width/height
Width = Height = (int)round_up_to_pow2((unsigned)std::max(g_Renderer.GetWidth(), g_Renderer.GetHeight()));
}
// Clamp to the maximum texture size
Width = std::min(Width, (int)ogl_max_tex_size);
Height = std::min(Height, (int)ogl_max_tex_size);
// Since we're using a framebuffer object, the whole texture is available
EffectiveWidth = Width;
EffectiveHeight = Height;
const char* formatname;
switch(DepthTextureBits)
{
case 16: formatname = "DEPTH_COMPONENT16"; break;
case 24: formatname = "DEPTH_COMPONENT24"; break;
case 32: formatname = "DEPTH_COMPONENT32"; break;
default: formatname = "DEPTH_COMPONENT"; break;
}
LOGMESSAGE(L"Creating shadow texture (size %dx%d) (format = %hs)",
Width, Height, formatname);
if (g_Renderer.m_Options.m_ShadowAlphaFix)
{
glGenTextures(1, &DummyTexture);
g_Renderer.BindTexture(0, DummyTexture);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, Width, Height, 0, GL_RGBA, GL_UNSIGNED_BYTE, NULL);
}
glGenTextures(1, &Texture);
g_Renderer.BindTexture(0, Texture);
GLenum format;
#if CONFIG2_GLES
format = GL_DEPTH_COMPONENT;
#else
switch (DepthTextureBits)
{
case 16: format = GL_DEPTH_COMPONENT16; break;
case 24: format = GL_DEPTH_COMPONENT24; break;
case 32: format = GL_DEPTH_COMPONENT32; break;
default: format = GL_DEPTH_COMPONENT; break;
}
#endif
glTexImage2D(GL_TEXTURE_2D, 0, format, Width, Height, 0, GL_DEPTH_COMPONENT, GL_UNSIGNED_SHORT, NULL);
// GLES requires type == UNSIGNED_SHORT or UNSIGNED_INT
// set texture parameters
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
#if CONFIG2_GLES
// GLES doesn't do depth comparisons, so treat it as a
// basic unfiltered depth texture
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
#else
// Enable automatic depth comparisons
glTexParameteri(GL_TEXTURE_2D, GL_DEPTH_TEXTURE_MODE, GL_INTENSITY);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_COMPARE_MODE, GL_COMPARE_R_TO_TEXTURE);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_COMPARE_FUNC, GL_LEQUAL);
// Use GL_LINEAR to trigger automatic PCF on some devices
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
#endif
ogl_WarnIfError();
// bind to framebuffer object
glBindTexture(GL_TEXTURE_2D, 0);
pglBindFramebufferEXT(GL_FRAMEBUFFER_EXT, Framebuffer);
pglFramebufferTexture2DEXT(GL_FRAMEBUFFER_EXT, GL_DEPTH_ATTACHMENT_EXT, GL_TEXTURE_2D, Texture, 0);
if (g_Renderer.m_Options.m_ShadowAlphaFix)
{
pglFramebufferTexture2DEXT(GL_FRAMEBUFFER_EXT, GL_COLOR_ATTACHMENT0_EXT, GL_TEXTURE_2D, DummyTexture, 0);
}
else
{
#if CONFIG2_GLES
#warning TODO: figure out whether the glDrawBuffer/glReadBuffer stuff is needed, since it is not supported by GLES
#else
glDrawBuffer(GL_NONE);
#endif
}
#if !CONFIG2_GLES
glReadBuffer(GL_NONE);
#endif
ogl_WarnIfError();
GLenum status = pglCheckFramebufferStatusEXT(GL_FRAMEBUFFER_EXT);
pglBindFramebufferEXT(GL_FRAMEBUFFER_EXT, 0);
if (status != GL_FRAMEBUFFER_COMPLETE_EXT)
{
LOGWARNING(L"Framebuffer object incomplete: 0x%04X", status);
// Disable shadow rendering (but let the user try again if they want)
g_Renderer.m_Options.m_Shadows = false;
}
FilterOffsets[0] = -0.4f/Width;
FilterOffsets[1] = 1.0f/Height;
FilterOffsets[2] = -1.0f/Width;
FilterOffsets[3] = -0.4f/Height;
FilterOffsets[4] = 0.4f/Width;
FilterOffsets[5] = -1.0f/Height;
FilterOffsets[6] = 1.0f/Width;
FilterOffsets[7] = 0.4f/Height;
}
///////////////////////////////////////////////////////////////////////////////////////////////////
// Set up to render into shadow map texture
void ShadowMap::BeginRender()
{
// HACK HACK: this depends in non-obvious ways on the behaviour of the caller
// Calc remaining shadow matrices
m->CalcShadowMatrices();
{
PROFILE("bind framebuffer");
glBindTexture(GL_TEXTURE_2D, 0);
pglBindFramebufferEXT(GL_FRAMEBUFFER_EXT, m->Framebuffer);
}
// clear buffers
{
PROFILE("clear depth texture");
// In case we used m_ShadowAlphaFix, we ought to clear the unused
// color buffer too, else Mali 400 drivers get confused.
// Might as well clear stencil too for completeness.
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT | GL_STENCIL_BUFFER_BIT);
glColorMask(0,0,0,0);
}
// setup viewport
glViewport(0, 0, m->EffectiveWidth, m->EffectiveHeight);
m->SavedViewCamera = g_Renderer.GetViewCamera();
CCamera c = m->SavedViewCamera;
c.SetProjection(m->LightProjection);
c.GetOrientation() = m->InvLightTransform;
g_Renderer.SetViewCamera(c);
#if !CONFIG2_GLES
glMatrixMode(GL_PROJECTION);
glLoadMatrixf(&m->LightProjection._11);
glMatrixMode(GL_MODELVIEW);
glLoadMatrixf(&m->LightTransform._11);
#endif
glEnable(GL_SCISSOR_TEST);
glScissor(1,1, m->EffectiveWidth-2, m->EffectiveHeight-2);
}
///////////////////////////////////////////////////////////////////////////////////////////////////
// Finish rendering into shadow map texture
void ShadowMap::EndRender()
{
glDisable(GL_SCISSOR_TEST);
g_Renderer.SetViewCamera(m->SavedViewCamera);
{
PROFILE("unbind framebuffer");
pglBindFramebufferEXT(GL_FRAMEBUFFER_EXT, 0);
}
glViewport(0, 0, g_Renderer.GetWidth(), g_Renderer.GetHeight());
glColorMask(1,1,1,1);
}
///////////////////////////////////////////////////////////////////////////////////////////////////
// Retrieve the texture handle and texture matrix for shadowing
GLuint ShadowMap::GetTexture() const
{
return m->Texture;
}
const CMatrix3D& ShadowMap::GetTextureMatrix() const
{
return m->TextureMatrix;
}
///////////////////////////////////////////////////////////////////////////////////////////////////
// Depth texture bits
int ShadowMap::GetDepthTextureBits() const
{
return m->DepthTextureBits;
}
void ShadowMap::SetDepthTextureBits(int bits)
{
if (bits != m->DepthTextureBits)
{
if (m->Texture)
{
glDeleteTextures(1, &m->Texture);
m->Texture = 0;
}
m->Width = m->Height = 0;
m->DepthTextureBits = bits;
}
}
const float* ShadowMap::GetFilterOffsets() const
{
return m->FilterOffsets;
}
//////////////////////////////////////////////////////////////////////////////
void ShadowMap::RenderDebugBounds()
{
CShaderTechniquePtr shaderTech = g_Renderer.GetShaderManager().LoadEffect("gui_solid");
shaderTech->BeginPass();
CShaderProgramPtr shader = shaderTech->GetShader();
glDepthMask(0);
glDisable(GL_CULL_FACE);
// Render shadow bound
shader->Uniform("transform", g_Renderer.GetViewCamera().GetViewProjection() * m->InvLightTransform);
glEnable(GL_BLEND);
glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
shader->Uniform("color", 0.0f, 0.0f, 1.0f, 0.25f);
m->ShadowBound.Render(shader);
glDisable(GL_BLEND);
shader->Uniform("color", 0.0f, 0.0f, 1.0f, 1.0f);
m->ShadowBound.RenderOutline(shader);
// Draw a funny line/triangle direction indicator thing for unknown reasons
float shadowLineVerts[] = {
0.0, 0.0, 0.0,
0.0, 0.0, 50.0,
0.0, 0.0, 50.0,
50.0, 0.0, 50.0,
50.0, 0.0, 50.0,
0.0, 50.0, 50.0,
0.0, 50.0, 50.0,
0.0, 0.0, 50.0
};
shader->VertexPointer(3, GL_FLOAT, 0, shadowLineVerts);
shader->AssertPointersBound();
glDrawArrays(GL_LINES, 0, 8);
shaderTech->EndPass();
#if 0
CMatrix3D InvTexTransform;
m->TextureMatrix.GetInverse(InvTexTransform);
// Render representative texture rectangle
glPushMatrix();
glMultMatrixf(&InvTexTransform._11);
glEnable(GL_BLEND);
glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
glColor4ub(255,0,0,64);
glBegin(GL_QUADS);
glVertex3f(0.0, 0.0, 0.0);
glVertex3f(1.0, 0.0, 0.0);
glVertex3f(1.0, 1.0, 0.0);
glVertex3f(0.0, 1.0, 0.0);
glEnd();
glDisable(GL_BLEND);
glPolygonMode(GL_FRONT_AND_BACK, GL_LINE);
glColor3ub(255,0,0);
glBegin(GL_QUADS);
glVertex3f(0.0, 0.0, 0.0);
glVertex3f(1.0, 0.0, 0.0);
glVertex3f(1.0, 1.0, 0.0);
glVertex3f(0.0, 1.0, 0.0);
glEnd();
glPolygonMode(GL_FRONT_AND_BACK, GL_FILL);
glPopMatrix();
#endif
glEnable(GL_CULL_FACE);
glDepthMask(1);
}
void ShadowMap::RenderDebugTexture()
{
glDepthMask(0);
glDisable(GL_DEPTH_TEST);
#if !CONFIG2_GLES
g_Renderer.BindTexture(0, m->Texture);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_COMPARE_MODE, GL_NONE);
#endif
CShaderTechniquePtr texTech = g_Renderer.GetShaderManager().LoadEffect("gui_basic");
texTech->BeginPass();
CShaderProgramPtr texShader = texTech->GetShader();
texShader->Uniform("transform", GetDefaultGuiMatrix());
texShader->BindTexture("tex", m->Texture);
float s = 256.f;
float boxVerts[] = {
0,0, 0,s, s,0,
s,0, 0,s, s,s
};
float boxUV[] = {
0,0, 0,1, 1,0,
1,0, 0,1, 1,1
};
texShader->VertexPointer(2, GL_FLOAT, 0, boxVerts);
texShader->TexCoordPointer(GL_TEXTURE0, 2, GL_FLOAT, 0, boxUV);
texShader->AssertPointersBound();
glDrawArrays(GL_TRIANGLES, 0, 6);
texTech->EndPass();
#if !CONFIG2_GLES
g_Renderer.BindTexture(0, m->Texture);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_COMPARE_MODE, GL_COMPARE_R_TO_TEXTURE);
#endif
glEnable(GL_DEPTH_TEST);
glDepthMask(1);
}
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