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| author | Zolnai Tamás <tamas.zolnai@collabora.com> | 2014-09-17 08:04:36 +0200 |
|---|---|---|
| committer | Zolnai Tamás <tamas.zolnai@collabora.com> | 2014-09-17 09:59:50 +0200 |
| commit | 079c861f08d27aa8b6368aebc37f235979049286 (patch) | |
| tree | 835917e048fe884135f8fbea373579c20e7ac81d /chart2 | |
| parent | b3d50feaa87b670baf68288974005ac26ad31736 (diff) | |
fdo#81237: 2D OpenGL charts was upside-down
The problem is that LO drawinglayer uses a coordinate system
with an origin at the top-left corner of the screen, while
OpenGL uses a complete coordinate system (with all four
quarters, e.g.: allows negative values). The points in
LO are always positive values which means they are drawn
in the first quarter of the OpenGL coordinate system which
also means that the origin is at the bottom-left corner
of the scene. This difference causes the flipped scene.
* To solve that problem scale the projection matrix with -1.0f
along the y axis.
* glDisable(GL_CULL_FACE) is necessary to avoid dropping primitives
after scaling with -1.0.
* Since projection matrix mirrors also the textures we don't need to
do that inside the ConvertBitmapExToRGBATextureBuffer() method.
Change-Id: Ieba642f3e665778a12368fe50a20865ec8f73514
Diffstat (limited to 'chart2')
| -rw-r--r-- | chart2/source/view/main/OpenGLRender.cxx | 8 |
1 files changed, 5 insertions, 3 deletions
diff --git a/chart2/source/view/main/OpenGLRender.cxx b/chart2/source/view/main/OpenGLRender.cxx index 7c328b91303c..428b300c1d0e 100644 --- a/chart2/source/view/main/OpenGLRender.cxx +++ b/chart2/source/view/main/OpenGLRender.cxx @@ -87,7 +87,7 @@ GLfloat texCoords[] = { int OpenGLRender::InitOpenGL() { glEnable(GL_TEXTURE_2D); - glEnable(GL_CULL_FACE); + glDisable(GL_CULL_FACE); glCullFace(GL_BACK); glPolygonMode(GL_FRONT_AND_BACK, GL_FILL); // Enable depth test @@ -107,7 +107,8 @@ int OpenGLRender::InitOpenGL() glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT); //Init the Projection matrix - m_Projection = glm::ortho(0.f, float(m_iWidth), 0.f, float(m_iHeight), -1.f, 1.f); + m_Projection = glm::ortho(0.f, float(m_iWidth), -float(m_iHeight), 0.f, -1.f, 1.f); + m_Projection = m_Projection * glm::scale(1.0f, -1.0f, 1.0f); m_View = glm::lookAt(glm::vec3(0,0,1), // Camera is at (4,3,-3), in World Space glm::vec3(0,0,0), // and looks at the origin glm::vec3(0,1,0) // Head is up (set to 0,-1,0 to look upside-down) @@ -356,7 +357,8 @@ void OpenGLRender::SetSize(int width, int height) { m_iWidth = width; m_iHeight = height; - m_Projection = glm::ortho(0.f, float(m_iWidth), 0.f, float(m_iHeight), -4.f, 3.f); + m_Projection = glm::ortho(0.f, float(m_iWidth), -float(m_iHeight), 0.f, -4.f, 3.f); + m_Projection = m_Projection * glm::scale(1.0f, -1.0f, 1.0f); } void OpenGLRender::SetLine2DColor(sal_uInt8 r, sal_uInt8 g, sal_uInt8 b, sal_uInt8 nAlpha) |