drawing lines with triangles

5 files changed, 74 insertions, 34 deletions

diff --git a/include/llmr/geometry/buffer.hpp b/include/llmr/geometry/buffer.hpp
index 1177bb196e..1b9e5c6307 100644
--- a/include/llmr/geometry/buffer.hpp
+++ b/include/llmr/geometry/buffer.hpp
@@ -8,7 +8,7 @@
 namespace llmr {
 
 template <
-    size_t itemSize,
+    size_t item_size,
     int bufferType = GL_ARRAY_BUFFER,
     size_t defaultLength = 8192
 >
@@ -44,6 +44,7 @@ public:
         }
     }
 
+
 protected:
     // increase the buffer size by at least /required/ bytes.
     void *addElement() {
@@ -57,6 +58,9 @@ protected:
         return static_cast<char *>(array) + (pos - itemSize);
     }
 
+public:
+    const size_t itemSize = item_size;
+
 private:
     // CPU buffer
     void *array = nullptr;
diff --git a/include/llmr/geometry/elements_buffer.hpp b/include/llmr/geometry/elements_buffer.hpp
new file mode 100644
index 0000000000..82d97f8b6d
--- /dev/null
+++ b/include/llmr/geometry/elements_buffer.hpp
@@ -0,0 +1,30 @@
+#ifndef LLMR_GEOMETRY_TRIANGLE_ELEMENTS_BUFFER
+#define LLMR_GEOMETRY_TRIANGLE_ELEMENTS_BUFFER
+
+#include "buffer.hpp"
+
+namespace llmr {
+
+class TriangleElementsBuffer : public Buffer<
+    6, // bytes per triangle (3 * unsigned short == 6 bytes)
+    GL_ELEMENT_ARRAY_BUFFER
+> {
+public:
+    typedef uint16_t element_type;
+
+    void add(element_type a, element_type b, element_type c);
+};
+
+class PointElementsBuffer : public Buffer<
+    2, // bytes per point (1 unsigned short)
+    GL_ELEMENT_ARRAY_BUFFER
+> {
+public:
+    typedef uint16_t element_type;
+
+    void add(element_type a);
+};
+
+}
+
+#endif
diff --git a/include/llmr/geometry/fill_buffer.hpp b/include/llmr/geometry/fill_buffer.hpp
index f413715042..90265b8b97 100644
--- a/include/llmr/geometry/fill_buffer.hpp
+++ b/include/llmr/geometry/fill_buffer.hpp
@@ -7,7 +7,6 @@
 
 namespace llmr {
 
-
 class FillVertexBuffer : public Buffer<
     4 // bytes per coordinates (2 * unsigned short == 4 bytes)
 > {
@@ -18,17 +17,6 @@ public:
     void add(vertex_type x, vertex_type y);
 };
 
-
-class FillElementsBuffer : public Buffer<
-    6, // bytes per triangle (3 * unsigned short == 6 bytes)
-    GL_ELEMENT_ARRAY_BUFFER
-> {
-public:
-    typedef uint16_t element_type;
-
-    void add(element_type a, element_type b, element_type c);
-};
-
 }
 
 #endif
diff --git a/include/llmr/geometry/line_buffer.hpp b/include/llmr/geometry/line_buffer.hpp
index ccbdce1191..a18ea810ae 100644
--- a/include/llmr/geometry/line_buffer.hpp
+++ b/include/llmr/geometry/line_buffer.hpp
@@ -5,8 +5,7 @@
 
 namespace llmr {
 
-
-class LineBuffer : public Buffer<
+class LineVertexBuffer : public Buffer<
     8 // 2 coordinates per vertex + 1 linesofar + 1 extrude coord pair == 4 (== 8 bytes)
 > {
 public:
@@ -31,20 +30,10 @@ public:
      * @param {number} tx texture normal
      * @param {number} ty texture normal
      */
-    void add(vertex_type x, vertex_type y, float ex, float ey, int8_t tx, int8_t ty, int32_t linesofar = 0);
-
-    /*
-     * Add a degenerate triangle to the buffer
-     *
-     * > So we need a way to get from the end of one triangle strip
-     * to the beginning of the next strip without actually filling triangles
-     * on the way. We can do this with "degenerate" triangles: We simply
-     * repeat the last coordinate of the first triangle strip and the first
-     * coordinate of the next triangle strip.
-     */
-    void addDegenerate();
+    size_t add(vertex_type x, vertex_type y, float ex, float ey, int8_t tx, int8_t ty, int32_t linesofar = 0);
 };
 
+
 }
 
 #endif
diff --git a/include/llmr/geometry/vao.hpp b/include/llmr/geometry/vao.hpp
index 49401e01d2..a2a5a8a0d0 100644
--- a/include/llmr/geometry/vao.hpp
+++ b/include/llmr/geometry/vao.hpp
@@ -10,19 +10,47 @@ namespace llmr {
 template <typename Shader>
 class VertexArrayObject {
 public:
-    template <typename Buffer>
-    void bind(Shader& shader, Buffer& buffer, char *offset) {
+    template <typename VertexBuffer>
+    void bind(Shader& shader, VertexBuffer& vertex_buffer, char *offset) {
         if (!vao) {
             glGenVertexArrays(1, &vao);
             glBindVertexArray(vao);
 
-            buffer.bind();
+            vertex_buffer.bind();
             shader.bind(offset);
 
-            buffer_ptr = &buffer;
+            vertex_buffer_ptr = &vertex_buffer;
+            elements_buffer_ptr = nullptr;
             offset_ptr = offset;
-        } else if (buffer_ptr != &buffer) {
-            throw std::runtime_error("trying to bind VAO to another buffer");
+        } else if (vertex_buffer_ptr != &vertex_buffer) {
+            throw std::runtime_error("trying to bind VAO to another vertex buffer");
+        } else if (elements_buffer_ptr != nullptr) {
+            throw std::runtime_error("trying to bind VAO to another elements buffer");
+        } else if (offset_ptr != offset) {
+            throw std::runtime_error("trying to bind VAO to another offset");
+        } else {
+            // We have been given the correct information.
+            glBindVertexArray(vao);
+        }
+    }
+
+    template <typename VertexBuffer, typename ElementsBuffer>
+    void bind(Shader& shader, VertexBuffer& vertex_buffer, ElementsBuffer& elements_buffer, char *offset) {
+        if (!vao) {
+            glGenVertexArrays(1, &vao);
+            glBindVertexArray(vao);
+
+            vertex_buffer.bind();
+            elements_buffer.bind();
+            shader.bind(offset);
+
+            vertex_buffer_ptr = &vertex_buffer;
+            elements_buffer_ptr = &elements_buffer;
+            offset_ptr = offset;
+        } else if (vertex_buffer_ptr != &vertex_buffer) {
+            throw std::runtime_error("trying to bind VAO to another vertex buffer");
+        } else if (elements_buffer_ptr != &elements_buffer) {
+            throw std::runtime_error("trying to bind VAO to another elements buffer");
         } else if (offset_ptr != offset) {
             throw std::runtime_error("trying to bind VAO to another offset");
         } else {
@@ -42,7 +70,8 @@ private:
 
     // For debug reasons, we're storing the bind information so that we can
     // detect errors and report
-    void *buffer_ptr = nullptr;
+    void *vertex_buffer_ptr = nullptr;
+    void *elements_buffer_ptr = nullptr;
     char *offset_ptr = 0;
 };